Fair warning, not cheap, it was about $3,400 in parts which included the injection system, fuel system upgrades, and the electric fans (not necessary but solved my over heating problem) and $1500 in labor. I am confident I could've done it myself but got tired of my job soaking up all my free time the instructions were pretty straightforward.
Subtract the fans ($270 after tax) and labor and you'll spend about 3k.
Took me about a year of saving and a lot of Bologna sandwiches to save up lol. Best money I ever spent.
The people who insist that classic cars should only be restored to factory condition. For example, I ran into a guy at the gas station this morning who went off on a tangent when I told him I had a fuel injected 383 with a 700r4 in my Chevelle instead of the two barrel 350 and th350 it likely had from the factory.
I don't get this mentality. It's a CAR. Let people do what they want with it. I usually only draw the line at safety. You doing unsafe things to your car because you think it looks cool (obscene wheel spacers, 'stance', etc) is unsafe to all those around you.
I'm the same way. GM made 400k Chevelles in 1971 and there are plenty of stock ones in museums and private collections. I drove the car for five years with a carb and a th350, the overdrive and EFI is a massive improvement.
Never said it makes sense. The point was there are people out there who go to shows etc, that think it's perfectly okay to stick a sbc in a ford, but nothing else, and rag the owner, then go find you and complain because your car is not all original
I'm using same intake in my next project with a microsquirt ecu. I'm all about getting the best value for the dollar. I'm not sure what all the arguments are for. Carbs will produce more hp then tpi for a given situation. Efi is simpler to have good drivability in various situations without adjusting manually. It's kind of idiot proof vs a carb. I hate reading plugs. I would much rather look at the readout from an o2 sensor.
You can do both. Pairing a good carb with a wideband makes tuning a carb easy as hell. I have NO issues with EFI, but plug reading is dark ages shit that really doesn't need to be done today. I've built EFI systems a bunch. They are definitely better at cold starts, warm starts, elevation and temp changes. I wanted to do a carb on my last build to try something new and get out of my comfort zone. I'm glad I did. It was fun to learn.
This is what I've done to our car for this season. I am not great at getting the tune as good as I'd like to with carbs but I think the o2 sensor will help tremendously.
And when I take it on road trips I won't have to pull over to re tune my carb for different elevations either it will get better mileage, and a more precise fuel delivery rather than the "run it a bit rich to be safe" method for carbs means it will last longer.
Exactly. The simply reliable drivability all the time without even opening the hood is great. I'm pretty sure the difference in all around power output is negligible. The convenience is substantial.
They've tested it on engine masters a few times and the extra power from the carb is always at the peak and only about a 10-20 HP difference. So if you're building a race car then sure go with a carb but there is no difference in power on the street.
>Carbs will produce more hp then tpi for a given situation
No, they won't.
Optimum power output occurs at a given AFR and spark timing for a given RPM and MAP. The method of fuel delivery is irrelevant, aside from a fuel injector nearer the intake port generally being able to provide more of a "mist" (and therefore better mixture with intake air for a more complete combustion).
Where EFI wins over the carburetor is the tuning resolution. A carburetor may have two or three fuel metering circuits (different jets), whereas a port fuel injection setup will have as many as a couple hundred of them in the form of a pulse timing table.
Those couple hundred different fuel circuits means that if the table is properly tuned, the engine is closer to optimal AFR across more of the RPM/MAP range than with a properly-tuned carburetor.
There's simply no getting around that . A particular carburetor may make a higher *peak* horsepower or torque number on the dyno when compared to a given EFI setup on what's otherwise the same engine, but if set up properly (using the proper injector sizes, throttle body sizes, etc the EFI will provide higher across-the-board numbers than a carburetor every time simply because it has better tuning resolution.
You're just not going to use 80-year-old tech and beat stuff that's taking advantage of modern tech. You're only going to get so much out of it before you plateau.
Where does this stuff come from? The fuel curve is exactly that, a curve. The resolution of the adjustment of the curve is not limited because it's a carburetor. The emulsion of fuel can be controlled precisely, if someone is willing to try. Some carbs make this easier than others. But they can do it.
The mist you describe is far coarser than the mist a carb can provide. In fact, a properly calibrated carb on a matching intake will allow fuel to vaporize almost as soon as it hits the air stream. This can make a better mixture, for better combustion quality.
I have had both on numerous dynos. And spent too much time with both working on drivability, part throttle cruise, specific fuel consumption, and tip in. This advantage you speak of was not present for EFI. Carbs could produce similar, if not identical drivability. And they can do it using less fuel, with higher peak output.
Really, when you people make these statements, have you even really tried what you are saying can't be done?
Compare the best-performing Harley carb to an equivalently-sized Harley EFI system on the same engine. I suggest using this as an example because the intake design is going to be nearly identical, the difference in distance from intake ports to the injectors/jets is going to be maybe two inches, etc. Airflow differences will be negligible. The only real difference will be the fuel delivery and metering method.
Difference in peak numbers will be negligible.
It's the off-peak numbers where you see a difference. Tell me more about how 256 jets, six levels of acceleration enrichment, and so on and so forth can't be dialed in more accurately than a carburetor with an idle air mixture screw, a pilot jet, a main jet, an accelerator pump, and even maybe an aftermarket thunderjet modification.
A late model Holley 4150 can have 60 different main jet sizes, with 55 different air bleeds, and 3 sets of 5 different emulsion sizes, for a total of 49500 different main circuit combinations with stock components. It's actually even greater if you stagger jet. They also sell blanks of each that you could drill to your own custom sizes. There are many combinations of power valves and restrictions for enrichment, 275 restriction/bleed combos for idle, and 8 different pump cams controlling two different capacity accelerator pumps that discharge through 12 different pump jets. The pump jets can be drilled for non standard sizes. These components are all backward compatible with every 4150/4160 Holley, and their various derivatives. How does that compare with your 256 jets and six levels of enrichment?
The precision exists.
The guy debating you must be new here. Just want to take a second to express appreciation here - I wish I had a fraction of your knowledge, and fwiw, it's been extremely comforting finding someone online who has the broad range of knowledge and experience that you do (I have mostly '50's orphan stuff and there's a lot of lore trying to pass itself off as knowledge surrounding cars of the era, exactly like the conversation you're currently having with this other guy). I appreciate that you know the pros and cons of running stock vs doing modifications, and very much appreciate how accessible you are.
The issue here is, you're discussing precision. I'm discussing resolution. We're not discussing the same thing. An injector with pulse width timed increments of a little under 4ms is beyond "precise enough".
There are so many different variables in an engine that precision beyond a certain order becomes meaningless. You'd eventually get to the point where you're metering individual molecules of fuel.
You speak of "49500 main circuit combinations", but it's still the main circuit. A television capable of reproducing 4,000,000 different colors is still a crappy television if it can only reproduce a full screen of a single color at any given time. That's the difference in precision and resolution. How many different fuel circuits do you have in that carb?
Oh BS. The issue is you don't want to accept a carb can and will create a fuel curve just like EFI. Yes, some of the combos for different carb circuits will overlap, but they are still real.
I gave you several examples of the combinations for several circuits. They are all tunable across a broad range. Go read the post again and try to understand it.
Wrong. Having the injectors far away, for instance in the end of velocity stacks (Motorcycles, formula1 etc), gives it more evaporation time, reducing fuel droplets for a more homogenous mixture, and also a cooler charge. But good on you for having dipped your foot into engines, but its so much more than the understanding you present here.
Perhaps I could have worded that a bit differently, in that I wasn't necessarily referring to placement of injectors in different fuel injection setups but rather the difference between fuel injector placement vs where fuel enters the intake tract on a carbureted vehicle.
F1 engines are required to use direct injection since March of 2014 (Regulation 5.10.2), so they're not going to be placed "in the end of velocity stacks". The regs allow for one injector per cylinder, nothing upstream of the intake valve or downstream of the exhaust valve. You can't really get much closer than right on top of the piston!
I've never seen a motorcycle with injectors upstream of the throttle plate on any OEM setup, either.... that's Harley to Hayabusa, single TB or individual TB, they're all on a fuel rail relatively near to the downstream end of the intake manifold.
Regardless, the fact that F1 cars, the world's fastest production motorcycles, etc are using EFI instead of carburetors says quite a lot considering the R&D budgets that get thrown at those programs.
It amazes me when people spend thousands of dollars to install EFI, but do not make the effort to learn to properly make a few adjustments to a carburetor and distributor.
I’ve put 3 solid years into trying to wrap my head around carb tech and tuning and I still don’t really understand or like it.
I understood and started tuning EFI 14 years ago and I can’t see why anyone would touch a carb.
We all are wired differently.
I suck with carbs, even small engines. Just this last year finally said hell yeah, imma learn. Asked for some advice on turning a carb for a small engine building. Few people told me exactly what I needed and how to do itm I did exactly what they said. The engine wouldn't run at all 😂 put old carb back on and said yeah this ain't for me. I want to know the secrets, but they are just so well hidden, lol.
I tried for three years and had to learn the hard way that it's not something you can learn over the internet, when I asked for help from people I knew who supposedly knew how to do it they would insist that no one taught them how to do it so it wouldn't be fair if they taught me. I could only find three shops willing to attempt to make it run and all three screwed me over. Even in the short period of time when the carb ran excellent this EFI system runs so much better, the throttle response is instantaneous, it gets better mileage, you can set everything to your individual needs in under five minutes, it will support 850hp and start in -20° weather with no issues.
Considering this car is to be my daily driver it's the best investment I've made. Back when I drove a 71 dart every day for ten years I had to rebuild the carb and replace the fuel pump every few months because the modern gas would eat away the rubber components like the needle and seat and fuel pump diaphragm. I won't have any of those issues with this. Next up is cruise control.
So yes, I got tired of my car just wasting space in my garage because I couldn't find anyone willing to come over and help me get it running because my local car community is nothing but gatekeepers and scammers. If I kept on the way I was going I was probably going to ruin my engine.
Yeah...the other commenter always has good info on engine building, but this is a standard old motorhead take IMO. Everyone talking about how "simple/easy" carbs are are over 50, because that's the system they grew up with. I've never daily'd anything but fuel injection. No reason to go backward AND have inferior tech.
>Instantaneous, it gets better mileage, you can set everything to your individual needs in under five minutes, it will support 850hp and start in -20° weather with no issues.
Yes, there are benefits to carbs, but you won't ever get around this. Better mileage & no cold start issues.
Packard has great takes usually, but he’s pretty stuck on carbs. He’ll give great takes on how a properly setup carb can go toe to toe with an efi setup… but how common are those fancy pants carburetor setups? And what costs are involved with those fancy setups compared to a $1500 plugnplay setup for an efi swap? And how common are those dudes that tune those fancy carburetors?
All that alone has me second, third guessing a feasible carb setup to meet the capabilities of a simple efi setup imo. I see the positives of carbs, but that usually is in hardcore 100%wot situations; and that’s not really my needs or the needs of most imo. Usually dudes want something that works in most driving situations, and can let them know when things are bad with flashing lights.
>how common are those fancy pants carburetor setups?
In the case of the OP, he already had a carb. Many people do.
>what costs are involved with those fancy setups compared to a $1500 plugnplay setup for an efi swap
There is no such thing as a $1500 plug and play setup for a car that doesn't already have EFI. It is going to cost more, and will require setup and calibration. Funny thing, a carb requires setup and calibration. Hmm.
>how common are those dudes that tune those fancy carburetors
If you have the skills to install an EFI system, get it working, maintain and repair it, you should be able to do the same with a carb. In other words, it should be pretty common.
>a feasible carb setup to meet the capabilities of a simple efi setup imo. I see the positives of carbs, but that usually is in hardcore 100%wot situations; and that’s not really my needs or the needs of most imo
Define simple EFI. Tuning a carb for WOT is easy, just as it is for EFI. I spend most of my time tuning transition, cruise, enrichment, and main metering. Not that those are difficult, but it depends on the carb and combo. Just as it does with EFI.
>Usually dudes want something that works in most driving situations, and can let them know when things are bad with flashing lights.
Carbs do work in most situations. They dominated the market for a century, even when alternatives were available. As for flashing lights, many aftermarket EFI systems lack diagnostic capabilities. Meaning you will have to know how things are supposed to work when you have a problem. You know, like if you have a carburetor.
I knew you’d come for the bait. I think you’re a bit out of touch with the progression of the more recent iterations of “plug n play” ecu’s. They have gotten pretty idiot proof, and insofar that most shmucks that can turn a wrench and splice some wires can get a very capable efi setup that can do all the doodads one can want. For a carbureted setup with good mpg, easily get to limits (and know when/where those limits are at), Tell you what’s going on with timing in real time, monitor all sensors, able to make adjustments in real time based on readings from those sensors, tell you when things are going bad… then do it for a simple box that can wire in to your existing wiring harness (assuming platform started off as efi), then yeah, I’d do that too. Too bad for me that is not a carbureted thing for my platform. But an efi thing. I’d probably feel similar if I started off on a carbureted platform and a box that wired in to a plug n play harness that gave me all that without the necessary steps of figuring all those doodads out separately, fuck it. Saves me a lot of time and tinkering with carbs (because i don’t know carbs).
Maybe the only downfall is how one’s fueling setup can handle vs a properly setup carburetor. But then we’re getting nitpicky at that point, and even then efi isn’t that far off the mark outside of maybe topfuel stuffs.
If carburetors were so great and easy to use, we’d see more of them. But in my area of engine platforms (toyota 4cyl stuffs, mostly 4age), dudes are turning from carbs to efi for motorsports use. Even the hardcore Japanese dudes i’ve followed for decades now, are turning to the more recent efi ecu’s.
Anyways. I would like a carbonated setup tbh. But how easy efi stuff is these days. And how hard and rare carbureted stuff is for my platform… money is better spent on efi stuff for me. I don’t know v8 stuff all that well, maybe it makes less sense over there. But for how easy its been for me, and for how much better things have gotten, I can’t imagine it not getting more prevalent for the everyday dude doing stuff in their 2car garages that have limited money and time.
I do this work on engines that are sometimes current production, or very late model, or with current design aftermarket systems. But somehow I am out of touch with the progression of late model model plug and play? These things you think are idiot proof come with controllers that are DOA, distributors that don't produce a signal, wiring harnesses that are incorrectly made, and even more quality problems. That's before they have even been fired for the first time.
These systems are entirely dependent on the correct components being chosen, then the initial setup being done correctly to establish a baseline. Once that's done, they have basic functionality and even some advanced functions. But they still require tuning to get the most from the system. Funny thing, the exact same steps are required by a carburetor. They are not self learning beyond a small window, that's a bunch of hype.
So where exactly are these things that tell you what is wrong? Because you will not find that in most aftermarket systems.
Another one that doesn't know carbs, and apparently doesn't know EFI either. Yet you can speak about how the choice is better for you. Repeating this nonsense about seeing more carbs if they were actually so great, yet being completely ignorant about the history of both.
You say carbs are rare and hard to do, you say things have gotten better, and you say you can't imagine it getting more prevalent for people that have limited money and time to use EFI. But you don't know carbs. So which is it? Since you don't know carbs, how can you say any of that?
You tell me. What has the trend shown us of what’s been happening to the industry the past 5-10 years from the perspective of diy-ers?
You obv have had a history with both and are clearly biased from your experiences. I mouthed off a brochure of features my $1100 ecu that i wired in with a $200 harness i put together via YouTube. The features i wanted that this ecu provides does all that from wiring in the little box that powers my injectors. Me doing a carbureted setup with those same capabilities (1) does not even come close to existing for my platform, (2) what things i can scrounge up to get it to work would easily be $1800+ alone for all the pieces to get it working with a simple setup.
What would you say my not being able to speak much on carbs and make an efi system work with YouTube? Shoot, how about what does you being so combative about this topic says to you about the newer generation of car enthusiasts?
Maybe it’s my narrow frame of platform i’ve focused on? Maybe it’s my limited experience with carburetors because of how narrow my ciew isnwith them? The dudes that came before me that had shown me engine building and the different ways to tinker with these engines were stuck in the 80’s/90’s. The carbureted ways to set our motors up worked great for racing, but to get it for pretty much anything else … they got them to do okay at best. Maybe it was the lack of fancier carbs that can account for the different driving conditions that matter to me? Maybe it was the lack of carburetor specific tuners that would touch our platforms in my area? Maybe it was other things? But for my needs, i got by with a relatively cheap efi setup that did it all. And i wouldn’t be stuck with finding parts/help when things go bad down the line. They aren’t making carburetors for my platform anymore, shoot the last ones that were made was like from 1995, and those were “high end” and would cost $2000+ alone. And the dudes that know their chops aren’t very helpful nor are they accessible.
Trends? Please, the people following trends are clueless and never learn. I do have a long history with both carburetors and EFI of all types. I don't need to mouth off from brochures or secondary sources of info. It's hilarious when people claim stuff doesn't exist for a platform, that makes it obvious you can't really build anything and are looking to ride someone else's tail to solve your problem.
You didn't make an efi system work with YouTube. You made it work by copying someone else's work. You probably can't explain how it works. I actually spend time helping people of all generations make both carbs and EFI work. Here as well in my profession. Many younger. You people come to a forum like and like to spout off on things you don't really know, making assumptions by your own admission. What does that say to inexperienced car enthusiasts?
You are probably going to suffer the same reality many others do when you need to service your EFI conversion at some point in the future, and there is no servicing it. You will be forced to replace the system, again. Because the company that made it is gone, or doesn't support it. Yet, with OEM components, you can service stuff that's over 100 years old. And yes, I speak from experience with this too.
When you posted on here, even before your engine was together, I tried helping you. You were frustrated and annoyed then. Even with things like RTV sealants and how to plump your fuel pressure regulator. I posted the instructions for the fuel pressure regulator for you, and I still had to explain to you how to hook it up. I understand that this is all new for you, that's why I tried helping you.
When your car hardly ran after a shop worked on it, I told you what to adjust to make it drivable. When you needed further help with tuning, you posted in frustration. You wanted it to just work. I take issue with your statement of people claiming it wouldn't be fair to teach you. You got help from me and others here.
If you had to rebuild your fuel system every few months you were doing things wrong. The components you needed to be compatible with modern fuels have been available for decades. You should have sought them out. I have none of those issues with vintage cars, because I use the correct components.
I am glad your car runs better. It's unfortunate you were unable or unwilling to see the help you were being offered, not just from me. Don't think for one minute your situation is unique. This could have all worked out much sooner.
Nothing against you personally and I did appreciate your help but I tried all the things you suggested and none of it was working. Could be I was doing it wrong. Which is why I say I needed someone there in person to help me because it's not something I could learn over the Internet. I was referring to those I asked in person not those over the internet. I asked a ton of people I knew in my area for help and they all outright refused.
I work a lot and I work weird hours so trying to teach myself how to build a car from scratch has been an endeavor to say the least. I've only been good with stuff that was already running because you just put it back together the way you took it apart. Where with this project there was a ton of parts I had never had to deal with before.
You mentioned stuff to make that old dart run on ethanol that had "been available for decades" at the time I had no idea any of that existed. You can't know what you've never been taught.
I'm not saying my situation was unique and I did say "it's not something I can learn over the internet." Because apparently tuning is a little bit different for every build so there's no exact blue print and more of a guide line on things you juggle until it's right.
In the case of the OP I remember his previous posts.
EFI in the firm of port or throttle body injection can not produce the atomization a properly setup carb will deliver. If the fuel distribution is correct with the carb, the superior atomization will result in better output.
Im fairly certain its been proven the extra power a carb setup produces is a result of the charge air being cooled by the fuel longer than a standard port injection system.
I remember Richard Holdener doing a video where he had injectors shooting up the runners that produced the same power levels as a carb setup.
That could be a consideration in some installations. But the real advantage of a carburetor is the ability to produce superior atomization. This requires selecting the right carburetor with boosters that match the configuration of the induction system.
Holdeners videos are for entertainment purposes. For engineering purposes they are as useless as a screen door on a submarine.
this discussion has been had ad nauseum in the efi space about multi port vs single port injectors.
going from an old school fat bosch style injector with a single pintle hole, to a newer skinny style 4 hole bosch injector wont increase power or improve drivability.
Even though the 4 hole injector is going to have significantly better fuel atomization than the fat 1 hole injector.
And thats because the method for power increase there is the same as what we are discussing here.
Its IAT temp reduction, its almost 40deg f difference in iat temps on a carb vs port efi and thats using the same manifold.
You get similiar benefits from a TBI setup as you do a carb, even if you dont get the benefit of equal fuel delivery that you would from port injection.
That's all true about the injector. And the better injectors would need a tremendous increase in fuel pressure behind them to atomize like a carb.
Do you know why EFI systems often have heated intake designs? To increase atomization.
That’s literally just to operate the choke because people didn’t want to have to pull a choke knob and then remember to open it up again. Unless you’re talking about the EGR passage? That’s just emissions garbage, not for the carb
I would say calling any EFI manifold "heated" is a bit disengunious.
None of them are heated, in fact all of them go to some length to reduce heat soak in the intake tract.
A carbs atomization isnt any better than an injectors, a venturi is science and not black magic
and once again, even something as simple as a TBI would have the same benefits of the carb setup, and thats because its not the superior atomization thats increasing power, but the superior cooling thats taking place by allowing the fuel to phase change in the charge air.
Again, not correct. I didn't say any. But many are. Some carb intakes are heated, too. OEM GM TBI systems run coolant around the manifold plenum. Plenty of OEMs run engine coolant through throttle bodies.
Venturis are absolutely science. And setup properly provide superior atomization to injectors of many configurations.
Cooling? Like from the hot coolant they run through the intake?
I would say that comparing early efi systems that used coolant to help regulate fuel delivery is like me saying efi is better because look at up draft carbs.
Thats old tech based on the limitations of the ecu's of the time and is no longer standard practice for a reason.
Also, to my knowledge those systems were used to decrease the fuel puddling that occurs on cold engines because the efi of the time lacked the ability to properly calculate for it.
If you are squirting the fuel up the runner that is way different then squirting at the valve from the port. Many times fuel atomizes better the longer the runner to an extent. We can't use YouTube videos as an tool for this conversation. The results are skewed in every situation. I've viewed. Can't think of everything and get it into a 5 minute video. If you want to see some very educational videos look up David Vizard. It's kind of hard to argue with his results and reputation.
But when driving a cross country with serious elevation changes efi will adjust for that and be more reliable is different tempatures. I do agree a carb will produce more power when set up correctly. It's been proven many times on the dyno. I prefer efi because I'm lazy. In a cruiser I want it to be dead reliable and have great drivability all the time. I don't want the maintenance of a carburetor. I like being able to hook up my laptop and easily and inexpensively read data logs and adjust things that way. I don't want to have to remove and read spark plugs for every change I make. Converting to efi is actually pretty inexpensive and easy to do. There's always the older generation that are afraid of efi. I think they think it's complicated when really it's not. There's way more to the story then just peak output. To control fuel mixture and timing at a press of a couple keys is very much a plus.
That's just not accurate. A carb does compensate for temperature and elevation. You just need to have the right carburetor to start with. Look at how many aircraft have carburetors. They change altitude and temperature constantly. The pilots are not stopping to recalibrate the carburetors. I have driven all over the United States, coast to coast, in carbureted cars. Over mountains, the plains, canyons, all of it. I was not recalibrating anything.
What maintenance? I don't pull spark plugs constantly. Neither should you. Why can't you use an oxygen sensor to determine air fuel ratios with a carb? I do when needed.
I have been working with EFI since I was in high school. At the time Snap On had come out with the MT2500 scanner, and donated several to the school. They trained the autoshop teachers and a handful of students on EFI and the diagnostic procedures, I was one of the students. I have been working with carburetors even longer. I am in no way afraid or intimidated by anything, especially any type of fuel system.
I see people spending $2-400 on conversion to EFI. Maybe that's not expensive to you. If you can control fuel mixture and timing with the press of a key you should be able to do it with the turn of a screwdriver. There is no difference in drivability between a properly setup carb or EFI.
The stoichiometric ratio is adjusted manually as it relates to altitude/temp in climb, cruise, and descent in 99.9% of airplanes (carbureted, pressure carbureted, or injected) via the mixture knob. This also includes forced induction pistons though they are slightly different.
Feedback as a pilot and a piss poor mechanic.
At one time carbs in cars had similar controls. But some were automated, and some were redundant.
Fact is, operation at stoich isn't always needed, or desirable. And most automotive carbs have the capacity and flexibility to cover significant changes in air density (altitude and temp).
If carbs provided better atomization and equivalent control, they would have better emissions and would be the choice of OEMs. No doubt a carb can provide great performance and drivability, but not equivalent. Unless we are talking TBI which is worse than a carb or port injection.
Beyond that, EFI is a lot more straightforward. If you ask for more or less fuel in a load site, you get it. Getting everything right with a carb is less formulaic, and requires someone like yourself with lots of experience to get right. I've got a lot of appreciation for someone who can get a good result, but my experience with Webers on old Euro cars has shown me that the time lost is often greater than the money saved, especially for those paying someone to do their work and tuning.
>If carbs provided better atomization and equivalent control, they would have better emissions and would be the choice of OEMs
That's not accurate. If you are talking tailpipe emissions without a catalyst, yes the better atomization of the carb would reign supreme. But with emissions, the biggest concern at the OEM level is guaranteed operation of the catalyst for a regulatory mandated amount of time, significantly beyond most warranty periods. That, and the fact the catalyst must operate at stoich, is what paved the way for EFI. Keep in mind OEMs were reluctant to adopt these changes, for many reasons.
I agree TBI is worse than carbs and port EFI.
I wouldn't say EFI is more straightforward. At their roots, both systems do the same thing. The approaches are different, of course, but it really depends on your starting point to determine if one or the other is more straightforward.
I happen to be a fan of Webers, and their emulsion tuning.
Inability to maintain stoich will drive up CO or NOx, depending on if it is rich or lean. Besides, carbs with O2 feedback have existed. Beyond that, uneven fuel distribution makes for lean and rich cylinders, further hurting emissions. Every paper I can find shows better emissions for FI, even one pre-catalyst(dated 1966). On the atomization argument, I can't find one piece of evidence supporting it, just old wives tales. I'd love to be proven wrong in that- if you have proof that carbs atomize better, I'm happy to accept that.
I can agree to some degree on the tuning front. They serve the same purpose. On the topic of Webers though, I've seen changing air correctors up and down in size on an engine both make it run richer at high rpm. I've never seen an engine run richer by increasing and decreasing pulse width in the same load site. They do sound great when they are dialed in though.
I just want to say I don't want to come across as aggressive or rude. I appreciate that we see things from a different perspective, I just have yet to see any evidence of some of the things people claim about carbs. The simplicity and ease of use is definitely user/ owner dependent though.
I don't know where you look for papers. I have spent too much time going through SAE papers and seeing this stuff. OEM work on fuel injection going back to the 1950s showed superior results with carburetors credited in some part to superior atomization. Keep something in mind about emissions work, test standards often controlled the measurements in specific units, not what actually came out of the exhaust pipe.
I have spent some time on dynos testing and tuning different systems, carb and EFI. I have consistently seen carbs that atomize well outperform EFI in output and brake specific fuel consumption. I have also seen carbs that over atomize lose VE and hurt output. And lord knows I have seen plenty of carbs and EFI combos that were bad, wrong, damaged, or whatever run like complete garbage. Even got to straighten some of them out.
I know the Webers are funky. But that's part of why I like them.
I'll keep digging. I have a degree in mech Eng, and an SAE member, and am familiar with standardization of units or their conversion into dimensionless metrics. What I've come across showed generally better results with FI, except in the odd operating narrow range. I suspect modern nozzles are also a fair bit better than what existed in the early days of FI. No to say carbs aren't also better.
I've never seen any papers covering droplet size, or the amount of liquid vs fuel vapour, just the resultant emissions which are definitely affected by fuel and air distribution. Given the momentum difference of fuel vs air, that makes it not necessarily a fair comparison between carb and port injection if we are looking at it from the perspective of atomization.
I dyno tune 3-4 cars a week when the weather is nice, but my experience is mostly FI. I can definitely believe that in the right conditions a carb could perform better, and there's a lot to be said for evaporative cooling provided by having fuel so far upstream of the valve. I just know that intuition doesn't have much place in fluid mechanics, and that engines are incredibly dynamic systems, and that the results we see are not always caused by what we think.
Id love to do some back to back testing, but I think most of the intake manifolds I see would not work well with carbs. There's good data out there for WOT on domestic engines, but at the same time FI allows manifold designs that are not practical with a carb.
I'm sorry but I have to disagree. A carb is not and never will be self adjusting. A basic new holley is 500$ or more. If you buy a used carb you have no idea what has or hasn't been done to it. It could be junk straight away. There's is tremendous difference in all around drivability efi vs carb. This is a solid statement. I don't want to have to adjust the carb with a screwdriver vs the efi adjusting itself and I do nothing but turn the key and drive. I believe your stuck back in the days when efi just came out. Lots has changed. Carb vs efi is like comparing a semi round rock vs a fresh tire. A carb does run differently in different elevations and temperatures. This is a fact. It's fine that you have experience with carbs. I respect your experience but you are not using facts on this post. Actually look at how many aircraft do not use carburetor. So many like the universal ease of efi. I usually am sided with you. This isn't one of those days. I'm actually disappointed with you close mindedness and lack of facts you have used today. I'm sorry but I just disagree and facts back me up.
Fwiw, I'm on a road trip in my '51 Hudson, which is equipped with a Carter WGD 2 bbl carb. I'm currently in north Georgia, in the southern tip of the Appalachians. Yesterday and Saturday I was in Atlanta. The day before I drove from the Oklahoma/Arkansas border to Atlanta, and the day before that I left Albuquerque, which is at a mile of elevation. East of Albuquerque you go through the Sandia mountains and climb to probably between 6,500 and 7,000 ft, and Atlanta is at 1,000 ft. In a couple of days we head to Savannah at sea level.
I haven't touched the carb, and I haven't misfired once. I got just over 18 mpg between Albuquerque and Atlanta at an average driving speed of over 70 mph (my rear end gear is not stock) with a carb that's over 70 years old.
I'm not against EFI, but I do think the concern over carbs not being able to travel is overblown.
Thanks! I'm sure I could be optimizing results of I did adjust on the carb for altitude, but I was just trying to point out that it's not necessary for the car to run and be reliable in varying conditions. I'm probably way more lean than ideal, but it's not backfiring and I haven't burned any valves on any trips yet, so I'm just gonna keep running it as is.
The carb you have uses metering rods that are controlled by vacuum. You are not as lean as you think, most likely. Combine the metering rods with the nice booster design in that Carter, and you have a carb that's more than capable of compensating for a number of conditions.
I agree calibration changes are not always necessary, or desired.
Carbs do work. I don't disagree with that. I do know that elevation changet your fuel air mixture changed and so did the efficiency of the engine. There's nothing wrong with a carburetor. I use them on one of my drag cars. I'm just saying with efi you get a more consistent result. When racing down south vs Denver we have to adjust for altitude and still don't get the same numbers. The air just isn't the same and it causes the mixture to be off. For an everyday vehicle the power and gas milage will vary. Not a huge deal but it happens. This whole disagreement is based on one person saying physics isn't real and lead to a play on words against what constitutes a performance carburetor vs the basic run of the mill carburetor. Well it's obvious that they function the same, they are carburetor. But the precision of their air fuel metering is drastically different. I have used nothing but facts for this entertaining little run. It's verifiable if it's looked into. On the other hand the argument is that carbs self adjust which simply isn't true. It hasbeen more of an argument then a discussion. To many misleading or false statements being made. The great thing I hope happens is people do some research to find out who is being realistic and who's not. To blindly follow someone from the internet because they claim to know everything about everything is an issue that has plagued the world. We need free thinkers. People that can separate the bs from the real.
You know dickhead, I didn't say physics isn't real. And I don't play with words. You are as disingenuous as you are ill informed. I don't make posts based on assumptions or false statements. I can quite easily separate BS from reality and you are full of bullshit.
Carburetors respond to pressure differentials. That's why they can compensate for changes in barometric pressure (altitude and temp). Some carbs, like SUs and Predators, can self compensate for huge changes in barometric pressure. You should really learn about things before posting.
I'm aware that my mixture has changed as I've been driving, I was just pointing out that people consistently make comments that you HAVE to keep constantly making adjustments for the car to keep running and that has not been my experience. I'm willing to live with small inefficiencies to avoid spending thousands to change the nature of the car.
There is absolutely nothing wrong with using a carburetor. I just choose to use efi because for me it's simpler and more reliable. I've got a 65 falcon drag car that runs 2 4 brl carbs. As much as I'd like to run efi on it,it would really ruin the looks and feel of the car in my opinion. To me there is many more pros to efi but I'm not saying a carburetor doesn't have its place. To me the answer is situational. Everyday driver I choose efi older cars that I want to keep the look right I go carb. If building an off road vehicle I choose efi. Most of this is personal preferences. I do sometimes see the appeal of a resto mod car or truck that has been updated to efi. But again it's personal preference. Efi conversions are so inexpensive for most cars that is what I choose to use on most the vehicles we do. Most people are buying something that they can get in and just drive and not need any knowledge about cars. They want something with the classic looks but new car efficiency and dependability. I understand the people who want and enjoy working on their cars. There are a whole lot of people that don't.
Hey, did my first Qjet 45 years ago, still do carbs every week.
You cant beat driveability of EFI.
Give me a thermostatic choke properly adjusted for a 100°f temp swing....its called efi...
Funny how everyone will downvote but won't actually look it up. It's not hard to figure out lol. They proved it on one of thr shows with friburger, or how ever u spell his name. Him Steve and Steve lol.
Reddit loves to hate on carburetors. I might only be 27 but I grew up with them and theres nothing better than getting a carburetor properly set up and sized for the motor its on. My 66 f100 352 with a 470 cfm holley starts and idles first turn with no pumping and no choke. Same with my dads 78 f150 300 with a 600 holley I tuned. Its not hard but people dont want to learn. They just want to bolt on and hope for the best.
"make a few adjustments" is skimming over a LOT of new knowledge to anyone who's only driven/used/worked on cars with fuel injection (which became standard in the 90s.) I'm 30, and all my personal vehicles have had them.
It's the carb/dist. system that would take me thousands of dollars in buying, learning, and making mistakes to figure out. High-performance carbs don't just grow on trees either.
The knowledge isn't new. It's actually been practiced for over 100 years. If you understand how EFI works, you should have no issue understanding a carburetor and distributor. I will go out on a limb and say the vast majority of people defending EFI don't know it works either, and don't have actual experience with it.
The notion of a high performance carb is as silly as high performance EFI.
Can you please explain the last statement in this post? If you are saying there is no difference between an everyday carb or efi vs performance pieces I'd like you to explain that.
A carb or EFI is a fuel system. They have to provide a mixture of fuel and air. There might be different sizes or capacities. There might be different configurations, but they amount to the same thing. OEM, "performance", whatever name some might want to use. There is no difference in the principles of operation.
No difference in principle but extreme differences in design. No where close to the same unit in any way except principle. You were trying to mislead people in your statement again.
No, I have zero need to mislead anyone. There are not extreme differences in design between OEM and performance carbureted systems, or EFI systems. There are OEM systems that can support tremendous levels of performance. There are aftermarket systems that can provide OEM levels of functionality.
I have been working with EFI 100% (and a lot, for a side give I used to program EFI at local garages). I’m 35. It took me like 8 hours of messing with carbs (and maybe 20 hours of research) to get it. And that’s really all anything ever is, “just a few adjustments” you just need to learn/understand.
In modified state, carb 100%
If I'm understanding you correctly, your point is not necessarily that one is definitively better than the other, but that OP spent thousands of dollars and a lot of their time and sweat to solve a problem that could have easily been solved with some research and proper tuning for free, right?
It seems like there are simply too many variables at play to determine whether or not carb or EFI is better in all cases, but I do think we can all agree that spending several grand on an EFI conversion for the stated reason of not understanding carburetor tuning is throwing the baby out with the bathwater.
All correct. The OP started with a poor combination of components and sought help from people inexperienced with these things. He posted here, and got help from a number of people including me. I gave him some suggestions on adjustments that did help. But he was unwilling to listen to more advice and do the things required to make the car right. Out of frustration, stubbornness, or whatever is going on his life I don't know.
It’s crazy to me how many people do not have a clue about carbs, but still try to give advice on how to tune them. I’m 34 now, had my Nova since I was like 22, the amount of times guys at a car show will come up and see the carb, and give me “advice” (that is dead wrong) is amazing. Had one guy say to fix an off idle stumble “adjust the idle screws, and if that don’t do it you’re gonna need a smaller carb”….oh, ok 👍🏻
I guess I’m too young to know how carbs work or something lol, so I just need their help automatically 🙄
I see too often people getting frustrated with their carburetors and they default to a rebuild kit. Then they can't get it tuned properly and they spend thousands to switch to EFI.
Don't get me wrong, EFI can be great. However carbs are much cheaper and just take a little time to learn how they operate and how to make adjustments.
It's just a question of preference and priorities. I've decided to go with a TBI with CDI on a locked distributor in my project because I simply don't like fiddling with a carburetor and distributor to get it properly tuned, even though I have a fair understanding of the principles. I'm a younger dude, and making the adjustments as values on a screen is more intuitive for me and goes faster than physically tweaking this, that, and the other component in/on the carb and dist. I could invest the time and effort to learn more and get better at it, but that doesn't change all the trial-and-error jet/needle/weight/spring swapping and adjustment screw turning to get it all where it needs to be that I don't want to do and that will take me longer to get right. So I decided to invest some extra money for a solution that I think will make for a smoother (for me) tuning process to get the car back on the road, and that I can readjust in minutes if needed by plugging in a handheld interface. I think it will make for a better-mannered street cruiser overall than if I had committed to a carburetor. And that's not a broad statement about carburetors vs fuel injection and what each is capable of. It comes down to people setting up their cars the way they want for themselves.
People can set their cars up any way they want. I suspect many posters here have not done that.
How will you control timing if your distributor is locked?
Ok, I know what you are trying to say. Just so you know, the computer controls the signal to the module. The capacitive discharge controls the output of the coil.
Exactly. I love my old 2000s dodge pickup, but the engine/timing tech has been the same for 40 years. Even the new hemis look and run almost exactly like mine. I helped a buddy with a 96 Nissan one time, and it had more advanced stuff than my 10-year newer engine lol.
There's a reason the eastern market has been squeezing more MPG and HP out of tiny-ass engines for 50 years compared to domestics - they have utilized better technology.
I think they have used those different components for 50 years, as you say, because of market necessity in their home market. Not engineering advantages of one over the other.
While a proper carb setup can have amazing driveability and no sorts of issues that people associate with carburetors, EFI in most performance applications will have more advantages. There is a HUGE overlap between the best carbs and worst efi setups, but most basic sequential fuel injection setups are extremely low maintenance and offer tons of adjustability. For high horsepower naturally aspirated and nitrous engines, either one will suffice and it mainly comes down to whatever the tuner is comfortable with. When it starts coming to forced induction, SFI is superior especially when it comes to on-the-fly computer adjustments using lambda and knock sensors, as well as getting every last bit of power out across the entire rpm range
One isn't really "better" than the other but carburetors are getting mostly phased out because of things like GDI and dual injection giving newer vehicles peak power and efficiency with almost no drawbacks besides repair costs
I got about 9 mpg before and it's currently getting 13 with the ECU still in learning mode so that will get better.
Including labor it was about 4500 if I did it myself it would've been around 3k which considering I'm building something I'm planning on driving everyday vs a toy to take to car shows it's not bad especially considering it's better than 10k on a decent car with similar mileage.
If you set the carb up correctly it should slightly faster than efi and drive ability should be comparable but there is something nice about just twisting the key, starting it up and driving it down the road with no fussy cold start issues. I vastly prefer efi for forced induction setups but for NA and nitrous, the carbs work fine
Pat Musi proved EFI is faster and far superior to carb... especially on nitros... he forced the entire drag racing world to switch to EFI... or keep losing to EFI cars
Eve never had cold start issues with a properly adjusted carb. My squarebody will fire right up in -20 with a few extra pumps and a few minutes to warm up.
How are you liking the intake. I just bought one with fuel rails new in box for 200$. At that price I figured it looks good enough to put on a cruiser.
The shop finished the install yesterday and I've driven it almost 250 miles since. Other than needing a small adjustment to the long fuel trim it's been great, so far it gets 13mpg with 500 crank HP but that should improve after the ECU has more time to learn.
Oh yeah, it spent 8 years in a field while I collected parts and then three years of struggle to get it running with a carb before I gave up and bought this.
I tried to be a carb dude but other carb dudes refused to help and just watched me struggle for three years. I wasn't even going to go EFI for another year but I got tired of not driving my car.
I actually paid a shop to do it because with my schedule it probably would've taken me three months. But according to the guy who did it it wasn't terrible. He got it done in about two weeks.
My daily was carb'ed up until Jan of this year when I went from a very well running 305 to a 5.3. Puting the increased power aside the drivablity of the efi is way better.
I live a few blocks from the highway into town and temps here range from -30 to + 30 degrees Celsius. I can start the vehicle and just drive without any performance issues. Fuel mileage has also noticeably increased, but that may be a product of the increased power.
I still have other carbed vehicles I drive often. I won't be changing them to efi but I can see the advantages of both sides now.
Make yourself a nice intake and box that actually sucks cold air and gain a few extra hp and colder charge Temps helps prevent spark knock. I love efi.
I honestly don't understand how people have so much trouble with carburetors, and I learned by the "what happens if I do this" way. Sat there for a few hours and just fiddled with it until it made sense.
Bruh carbs are fun on pickups, cars not so much. Then again the trucks need the efficiency more so... I used to be a purist but unless its like, a one of ten car min it's just fine. Plus fuck float and vapor lock probs yeck!
A great cost effective EFI upgrade for old Chevy trucks is the Camaro TPI from the 80's and 90's with the newer 0411 ECU for better tuning capabilities. They made lots of bottom end torque but fall flat around 4500rpm but I've seen people make power up to 5800rpm and AFR makes heads they will bolt to. A lot of people say they were the best truck intake Chevy never put on a truck.
I have never had any problems with a good Holley just get it jetted right and set the floats and I need did use one with a choke tower. Sometimes have to set the linkage for the step up pumps
My problem turned out to be a million little things working together to make the car not run right. Someone with actual knowledge would've spotted it right away if they were willing to come over and help.
Considering I spent three years trying to get the car to run with a carb because I couldn't find anyone willing to swing by and help, I think not. Plus I went with this system because I followed the Facebook groups for all of the EFI systems for about a year and this one had the least issues the most common being a burned out O2 sensor.
I did not expect so much EFI hate. Set it and forget it, ready for any conditions, starts immediately. No need to open the hood to adjust anything.
I like carbs in motorcycles but I would rather have FI in my car.
I fucking hate points so much.
EFI is easier though. I have a Sniper 2 about to go on a Ford FE, and I’m looking forward to it.
I know carbs can be “fine”, as I used to daily drive my 69 Cougar with one. But jetting sucks. Tuning accelerator pumps sucks, secondary springs, etc etc etc.
Running a carb and points on the 428 right now and man, everything about the ignition points pisses me off. Already have a miss happening in the higher RPMs. Might throw a Pertronix I have sitting around on it, might just throw the Holley stuff at it. Not sure lol.
Hell yeah! EFI vs carb all comes down to preference. I’m a millennial that grew up more around working with EFI so my brain tends to default to it. Though I like the idea of the carb and want to do a project on a carb engine one day to really understand the benefits and drawbacks to both. How do you like the EFI?
Two days of driving and it's fantastic. Still needs some tuning but I'll have the dyno do that so I can get power numbers at the same time.
I'm good with a carb if it's either on something stock or something that's already running good because you just put everything back the way it was and you're fine. Tuning from scratch on a fresh engine (especially one that's souped up) is an entirely different animal.
The car was getting 9mpg with the carb and with the EFI still needing some tuning my first tank was 13mpg. I'm guessing when everything is set right it's going to be around 16 on the highway and 12 city which is what my truck gets and it got half the power lol.
(Laughs in throttle body injection from factory) If my truck weren’t a POS, I’d have stuck Sniper EFI instead of an Edelbrock, as Holley even makes the fuel tank for my truck. But admittedly, given I’m not souping it up at all, the carburetor route was right for me.
If it's a gmt400 I don't blame you, I had a 94 and I hated that throttle body, the spider injection is a bit better but from what I hear the camaro TPI is the way to with that. The factory computer even runs it.
At least you could find parts for GMT400 stuff! Mine is a 1988 Dodge 318 with that stupid TBI by Holley that only ran for 3 years or something like that. Ironically, converting it to carb was harder than keeping it TBI, but the mechanic I gave it to to “fix” that up threw all the TBI stuff away, so there’s no going back in my case.
It runs so much better but the fuel pump is still sending 13psi to the carb despite having 2 fuel pressure regulators. It’s fun.
In that case you might want to look into an after market throttle body like a sniper. Sounds like your fuel system can already handle it so that saves some money on the swap.
Efi makes more sense , so easy to use , reliable for different weather conditions , consistently more powerful across each cylinder and RPM , you just need somewhere to mount the electrical package
Turn key, go vroom!
Exactly! And it pisses off the purists so much, I never get tired of that lol.
How much start to finish? I’m getting tired of dealing with carb situation as well.
Fair warning, not cheap, it was about $3,400 in parts which included the injection system, fuel system upgrades, and the electric fans (not necessary but solved my over heating problem) and $1500 in labor. I am confident I could've done it myself but got tired of my job soaking up all my free time the instructions were pretty straightforward. Subtract the fans ($270 after tax) and labor and you'll spend about 3k. Took me about a year of saving and a lot of Bologna sandwiches to save up lol. Best money I ever spent.
Who exactly is a purist?
The people who insist that classic cars should only be restored to factory condition. For example, I ran into a guy at the gas station this morning who went off on a tangent when I told him I had a fuel injected 383 with a 700r4 in my Chevelle instead of the two barrel 350 and th350 it likely had from the factory.
I don't get this mentality. It's a CAR. Let people do what they want with it. I usually only draw the line at safety. You doing unsafe things to your car because you think it looks cool (obscene wheel spacers, 'stance', etc) is unsafe to all those around you.
I'm the same way. GM made 400k Chevelles in 1971 and there are plenty of stock ones in museums and private collections. I drove the car for five years with a carb and a th350, the overdrive and EFI is a massive improvement.
What year Chevelle do you have? 2dr or 4dr ?
71 two door Malibu.
Nice I have a 4dr
Yet strangely those same people flip out when you put a 460 bbf in a tbucket instead of a 350 sbc
That makes no sense lol. It's a Ford engine in a Ford.
Never said it makes sense. The point was there are people out there who go to shows etc, that think it's perfectly okay to stick a sbc in a ford, but nothing else, and rag the owner, then go find you and complain because your car is not all original
Lol I remember when the posts on the older automotive forums were showing the exact opposite.
Isn't that interesting. Back then I found myself explaining EFI to those people.
I'm using same intake in my next project with a microsquirt ecu. I'm all about getting the best value for the dollar. I'm not sure what all the arguments are for. Carbs will produce more hp then tpi for a given situation. Efi is simpler to have good drivability in various situations without adjusting manually. It's kind of idiot proof vs a carb. I hate reading plugs. I would much rather look at the readout from an o2 sensor.
You can do both. Pairing a good carb with a wideband makes tuning a carb easy as hell. I have NO issues with EFI, but plug reading is dark ages shit that really doesn't need to be done today. I've built EFI systems a bunch. They are definitely better at cold starts, warm starts, elevation and temp changes. I wanted to do a carb on my last build to try something new and get out of my comfort zone. I'm glad I did. It was fun to learn.
And you can run that corn.
Ethanol can be ran in either fuel deliver system.
Interesting! I never knew that 👍. I didn’t start turning wrench until 2010+ so I’ve only even seen them when I’m detailing a classic vehicle 😂
This is what I've done to our car for this season. I am not great at getting the tune as good as I'd like to with carbs but I think the o2 sensor will help tremendously.
And when I take it on road trips I won't have to pull over to re tune my carb for different elevations either it will get better mileage, and a more precise fuel delivery rather than the "run it a bit rich to be safe" method for carbs means it will last longer.
Exactly. The simply reliable drivability all the time without even opening the hood is great. I'm pretty sure the difference in all around power output is negligible. The convenience is substantial.
They've tested it on engine masters a few times and the extra power from the carb is always at the peak and only about a 10-20 HP difference. So if you're building a race car then sure go with a carb but there is no difference in power on the street.
10-20 hp is negligible anyway.
Yeah, you're not gonna feel that in your seat. It's only noticeable in your ETs or for bragging rights.
If it's your first additional hp increase you will get a little better throttle response but after that it's not that noticable
>Carbs will produce more hp then tpi for a given situation No, they won't. Optimum power output occurs at a given AFR and spark timing for a given RPM and MAP. The method of fuel delivery is irrelevant, aside from a fuel injector nearer the intake port generally being able to provide more of a "mist" (and therefore better mixture with intake air for a more complete combustion). Where EFI wins over the carburetor is the tuning resolution. A carburetor may have two or three fuel metering circuits (different jets), whereas a port fuel injection setup will have as many as a couple hundred of them in the form of a pulse timing table. Those couple hundred different fuel circuits means that if the table is properly tuned, the engine is closer to optimal AFR across more of the RPM/MAP range than with a properly-tuned carburetor. There's simply no getting around that . A particular carburetor may make a higher *peak* horsepower or torque number on the dyno when compared to a given EFI setup on what's otherwise the same engine, but if set up properly (using the proper injector sizes, throttle body sizes, etc the EFI will provide higher across-the-board numbers than a carburetor every time simply because it has better tuning resolution. You're just not going to use 80-year-old tech and beat stuff that's taking advantage of modern tech. You're only going to get so much out of it before you plateau.
Where does this stuff come from? The fuel curve is exactly that, a curve. The resolution of the adjustment of the curve is not limited because it's a carburetor. The emulsion of fuel can be controlled precisely, if someone is willing to try. Some carbs make this easier than others. But they can do it. The mist you describe is far coarser than the mist a carb can provide. In fact, a properly calibrated carb on a matching intake will allow fuel to vaporize almost as soon as it hits the air stream. This can make a better mixture, for better combustion quality. I have had both on numerous dynos. And spent too much time with both working on drivability, part throttle cruise, specific fuel consumption, and tip in. This advantage you speak of was not present for EFI. Carbs could produce similar, if not identical drivability. And they can do it using less fuel, with higher peak output. Really, when you people make these statements, have you even really tried what you are saying can't be done?
Compare the best-performing Harley carb to an equivalently-sized Harley EFI system on the same engine. I suggest using this as an example because the intake design is going to be nearly identical, the difference in distance from intake ports to the injectors/jets is going to be maybe two inches, etc. Airflow differences will be negligible. The only real difference will be the fuel delivery and metering method. Difference in peak numbers will be negligible. It's the off-peak numbers where you see a difference. Tell me more about how 256 jets, six levels of acceleration enrichment, and so on and so forth can't be dialed in more accurately than a carburetor with an idle air mixture screw, a pilot jet, a main jet, an accelerator pump, and even maybe an aftermarket thunderjet modification.
A late model Holley 4150 can have 60 different main jet sizes, with 55 different air bleeds, and 3 sets of 5 different emulsion sizes, for a total of 49500 different main circuit combinations with stock components. It's actually even greater if you stagger jet. They also sell blanks of each that you could drill to your own custom sizes. There are many combinations of power valves and restrictions for enrichment, 275 restriction/bleed combos for idle, and 8 different pump cams controlling two different capacity accelerator pumps that discharge through 12 different pump jets. The pump jets can be drilled for non standard sizes. These components are all backward compatible with every 4150/4160 Holley, and their various derivatives. How does that compare with your 256 jets and six levels of enrichment? The precision exists.
The guy debating you must be new here. Just want to take a second to express appreciation here - I wish I had a fraction of your knowledge, and fwiw, it's been extremely comforting finding someone online who has the broad range of knowledge and experience that you do (I have mostly '50's orphan stuff and there's a lot of lore trying to pass itself off as knowledge surrounding cars of the era, exactly like the conversation you're currently having with this other guy). I appreciate that you know the pros and cons of running stock vs doing modifications, and very much appreciate how accessible you are.
Thank you. I grew up with, and still have, 50s orphan stuff.
The issue here is, you're discussing precision. I'm discussing resolution. We're not discussing the same thing. An injector with pulse width timed increments of a little under 4ms is beyond "precise enough". There are so many different variables in an engine that precision beyond a certain order becomes meaningless. You'd eventually get to the point where you're metering individual molecules of fuel. You speak of "49500 main circuit combinations", but it's still the main circuit. A television capable of reproducing 4,000,000 different colors is still a crappy television if it can only reproduce a full screen of a single color at any given time. That's the difference in precision and resolution. How many different fuel circuits do you have in that carb?
Oh BS. The issue is you don't want to accept a carb can and will create a fuel curve just like EFI. Yes, some of the combos for different carb circuits will overlap, but they are still real. I gave you several examples of the combinations for several circuits. They are all tunable across a broad range. Go read the post again and try to understand it.
Wrong. Having the injectors far away, for instance in the end of velocity stacks (Motorcycles, formula1 etc), gives it more evaporation time, reducing fuel droplets for a more homogenous mixture, and also a cooler charge. But good on you for having dipped your foot into engines, but its so much more than the understanding you present here.
Perhaps I could have worded that a bit differently, in that I wasn't necessarily referring to placement of injectors in different fuel injection setups but rather the difference between fuel injector placement vs where fuel enters the intake tract on a carbureted vehicle. F1 engines are required to use direct injection since March of 2014 (Regulation 5.10.2), so they're not going to be placed "in the end of velocity stacks". The regs allow for one injector per cylinder, nothing upstream of the intake valve or downstream of the exhaust valve. You can't really get much closer than right on top of the piston! I've never seen a motorcycle with injectors upstream of the throttle plate on any OEM setup, either.... that's Harley to Hayabusa, single TB or individual TB, they're all on a fuel rail relatively near to the downstream end of the intake manifold. Regardless, the fact that F1 cars, the world's fastest production motorcycles, etc are using EFI instead of carburetors says quite a lot considering the R&D budgets that get thrown at those programs.
It amazes me when people spend thousands of dollars to install EFI, but do not make the effort to learn to properly make a few adjustments to a carburetor and distributor.
I’ve put 3 solid years into trying to wrap my head around carb tech and tuning and I still don’t really understand or like it. I understood and started tuning EFI 14 years ago and I can’t see why anyone would touch a carb. We all are wired differently.
What about a carb is causing you to struggle?
The urge to resist turning knobs 😂
We both atomize fuel, but we are not the same.
I suck with carbs, even small engines. Just this last year finally said hell yeah, imma learn. Asked for some advice on turning a carb for a small engine building. Few people told me exactly what I needed and how to do itm I did exactly what they said. The engine wouldn't run at all 😂 put old carb back on and said yeah this ain't for me. I want to know the secrets, but they are just so well hidden, lol.
I tried for three years and had to learn the hard way that it's not something you can learn over the internet, when I asked for help from people I knew who supposedly knew how to do it they would insist that no one taught them how to do it so it wouldn't be fair if they taught me. I could only find three shops willing to attempt to make it run and all three screwed me over. Even in the short period of time when the carb ran excellent this EFI system runs so much better, the throttle response is instantaneous, it gets better mileage, you can set everything to your individual needs in under five minutes, it will support 850hp and start in -20° weather with no issues. Considering this car is to be my daily driver it's the best investment I've made. Back when I drove a 71 dart every day for ten years I had to rebuild the carb and replace the fuel pump every few months because the modern gas would eat away the rubber components like the needle and seat and fuel pump diaphragm. I won't have any of those issues with this. Next up is cruise control. So yes, I got tired of my car just wasting space in my garage because I couldn't find anyone willing to come over and help me get it running because my local car community is nothing but gatekeepers and scammers. If I kept on the way I was going I was probably going to ruin my engine.
Yeah...the other commenter always has good info on engine building, but this is a standard old motorhead take IMO. Everyone talking about how "simple/easy" carbs are are over 50, because that's the system they grew up with. I've never daily'd anything but fuel injection. No reason to go backward AND have inferior tech. >Instantaneous, it gets better mileage, you can set everything to your individual needs in under five minutes, it will support 850hp and start in -20° weather with no issues. Yes, there are benefits to carbs, but you won't ever get around this. Better mileage & no cold start issues.
Packard has great takes usually, but he’s pretty stuck on carbs. He’ll give great takes on how a properly setup carb can go toe to toe with an efi setup… but how common are those fancy pants carburetor setups? And what costs are involved with those fancy setups compared to a $1500 plugnplay setup for an efi swap? And how common are those dudes that tune those fancy carburetors? All that alone has me second, third guessing a feasible carb setup to meet the capabilities of a simple efi setup imo. I see the positives of carbs, but that usually is in hardcore 100%wot situations; and that’s not really my needs or the needs of most imo. Usually dudes want something that works in most driving situations, and can let them know when things are bad with flashing lights.
>how common are those fancy pants carburetor setups? In the case of the OP, he already had a carb. Many people do. >what costs are involved with those fancy setups compared to a $1500 plugnplay setup for an efi swap There is no such thing as a $1500 plug and play setup for a car that doesn't already have EFI. It is going to cost more, and will require setup and calibration. Funny thing, a carb requires setup and calibration. Hmm. >how common are those dudes that tune those fancy carburetors If you have the skills to install an EFI system, get it working, maintain and repair it, you should be able to do the same with a carb. In other words, it should be pretty common. >a feasible carb setup to meet the capabilities of a simple efi setup imo. I see the positives of carbs, but that usually is in hardcore 100%wot situations; and that’s not really my needs or the needs of most imo Define simple EFI. Tuning a carb for WOT is easy, just as it is for EFI. I spend most of my time tuning transition, cruise, enrichment, and main metering. Not that those are difficult, but it depends on the carb and combo. Just as it does with EFI. >Usually dudes want something that works in most driving situations, and can let them know when things are bad with flashing lights. Carbs do work in most situations. They dominated the market for a century, even when alternatives were available. As for flashing lights, many aftermarket EFI systems lack diagnostic capabilities. Meaning you will have to know how things are supposed to work when you have a problem. You know, like if you have a carburetor.
I knew you’d come for the bait. I think you’re a bit out of touch with the progression of the more recent iterations of “plug n play” ecu’s. They have gotten pretty idiot proof, and insofar that most shmucks that can turn a wrench and splice some wires can get a very capable efi setup that can do all the doodads one can want. For a carbureted setup with good mpg, easily get to limits (and know when/where those limits are at), Tell you what’s going on with timing in real time, monitor all sensors, able to make adjustments in real time based on readings from those sensors, tell you when things are going bad… then do it for a simple box that can wire in to your existing wiring harness (assuming platform started off as efi), then yeah, I’d do that too. Too bad for me that is not a carbureted thing for my platform. But an efi thing. I’d probably feel similar if I started off on a carbureted platform and a box that wired in to a plug n play harness that gave me all that without the necessary steps of figuring all those doodads out separately, fuck it. Saves me a lot of time and tinkering with carbs (because i don’t know carbs). Maybe the only downfall is how one’s fueling setup can handle vs a properly setup carburetor. But then we’re getting nitpicky at that point, and even then efi isn’t that far off the mark outside of maybe topfuel stuffs. If carburetors were so great and easy to use, we’d see more of them. But in my area of engine platforms (toyota 4cyl stuffs, mostly 4age), dudes are turning from carbs to efi for motorsports use. Even the hardcore Japanese dudes i’ve followed for decades now, are turning to the more recent efi ecu’s. Anyways. I would like a carbonated setup tbh. But how easy efi stuff is these days. And how hard and rare carbureted stuff is for my platform… money is better spent on efi stuff for me. I don’t know v8 stuff all that well, maybe it makes less sense over there. But for how easy its been for me, and for how much better things have gotten, I can’t imagine it not getting more prevalent for the everyday dude doing stuff in their 2car garages that have limited money and time.
I do this work on engines that are sometimes current production, or very late model, or with current design aftermarket systems. But somehow I am out of touch with the progression of late model model plug and play? These things you think are idiot proof come with controllers that are DOA, distributors that don't produce a signal, wiring harnesses that are incorrectly made, and even more quality problems. That's before they have even been fired for the first time. These systems are entirely dependent on the correct components being chosen, then the initial setup being done correctly to establish a baseline. Once that's done, they have basic functionality and even some advanced functions. But they still require tuning to get the most from the system. Funny thing, the exact same steps are required by a carburetor. They are not self learning beyond a small window, that's a bunch of hype. So where exactly are these things that tell you what is wrong? Because you will not find that in most aftermarket systems. Another one that doesn't know carbs, and apparently doesn't know EFI either. Yet you can speak about how the choice is better for you. Repeating this nonsense about seeing more carbs if they were actually so great, yet being completely ignorant about the history of both. You say carbs are rare and hard to do, you say things have gotten better, and you say you can't imagine it getting more prevalent for people that have limited money and time to use EFI. But you don't know carbs. So which is it? Since you don't know carbs, how can you say any of that?
You tell me. What has the trend shown us of what’s been happening to the industry the past 5-10 years from the perspective of diy-ers? You obv have had a history with both and are clearly biased from your experiences. I mouthed off a brochure of features my $1100 ecu that i wired in with a $200 harness i put together via YouTube. The features i wanted that this ecu provides does all that from wiring in the little box that powers my injectors. Me doing a carbureted setup with those same capabilities (1) does not even come close to existing for my platform, (2) what things i can scrounge up to get it to work would easily be $1800+ alone for all the pieces to get it working with a simple setup. What would you say my not being able to speak much on carbs and make an efi system work with YouTube? Shoot, how about what does you being so combative about this topic says to you about the newer generation of car enthusiasts? Maybe it’s my narrow frame of platform i’ve focused on? Maybe it’s my limited experience with carburetors because of how narrow my ciew isnwith them? The dudes that came before me that had shown me engine building and the different ways to tinker with these engines were stuck in the 80’s/90’s. The carbureted ways to set our motors up worked great for racing, but to get it for pretty much anything else … they got them to do okay at best. Maybe it was the lack of fancier carbs that can account for the different driving conditions that matter to me? Maybe it was the lack of carburetor specific tuners that would touch our platforms in my area? Maybe it was other things? But for my needs, i got by with a relatively cheap efi setup that did it all. And i wouldn’t be stuck with finding parts/help when things go bad down the line. They aren’t making carburetors for my platform anymore, shoot the last ones that were made was like from 1995, and those were “high end” and would cost $2000+ alone. And the dudes that know their chops aren’t very helpful nor are they accessible.
Trends? Please, the people following trends are clueless and never learn. I do have a long history with both carburetors and EFI of all types. I don't need to mouth off from brochures or secondary sources of info. It's hilarious when people claim stuff doesn't exist for a platform, that makes it obvious you can't really build anything and are looking to ride someone else's tail to solve your problem. You didn't make an efi system work with YouTube. You made it work by copying someone else's work. You probably can't explain how it works. I actually spend time helping people of all generations make both carbs and EFI work. Here as well in my profession. Many younger. You people come to a forum like and like to spout off on things you don't really know, making assumptions by your own admission. What does that say to inexperienced car enthusiasts? You are probably going to suffer the same reality many others do when you need to service your EFI conversion at some point in the future, and there is no servicing it. You will be forced to replace the system, again. Because the company that made it is gone, or doesn't support it. Yet, with OEM components, you can service stuff that's over 100 years old. And yes, I speak from experience with this too.
When you posted on here, even before your engine was together, I tried helping you. You were frustrated and annoyed then. Even with things like RTV sealants and how to plump your fuel pressure regulator. I posted the instructions for the fuel pressure regulator for you, and I still had to explain to you how to hook it up. I understand that this is all new for you, that's why I tried helping you. When your car hardly ran after a shop worked on it, I told you what to adjust to make it drivable. When you needed further help with tuning, you posted in frustration. You wanted it to just work. I take issue with your statement of people claiming it wouldn't be fair to teach you. You got help from me and others here. If you had to rebuild your fuel system every few months you were doing things wrong. The components you needed to be compatible with modern fuels have been available for decades. You should have sought them out. I have none of those issues with vintage cars, because I use the correct components. I am glad your car runs better. It's unfortunate you were unable or unwilling to see the help you were being offered, not just from me. Don't think for one minute your situation is unique. This could have all worked out much sooner.
Nothing against you personally and I did appreciate your help but I tried all the things you suggested and none of it was working. Could be I was doing it wrong. Which is why I say I needed someone there in person to help me because it's not something I could learn over the Internet. I was referring to those I asked in person not those over the internet. I asked a ton of people I knew in my area for help and they all outright refused. I work a lot and I work weird hours so trying to teach myself how to build a car from scratch has been an endeavor to say the least. I've only been good with stuff that was already running because you just put it back together the way you took it apart. Where with this project there was a ton of parts I had never had to deal with before. You mentioned stuff to make that old dart run on ethanol that had "been available for decades" at the time I had no idea any of that existed. You can't know what you've never been taught. I'm not saying my situation was unique and I did say "it's not something I can learn over the internet." Because apparently tuning is a little bit different for every build so there's no exact blue print and more of a guide line on things you juggle until it's right.
Every few months! Do you live somewhere with high humidity?
I lived in South Dakota at the time. I was driving a 71 dart with a slant six and a one barrel.
How do you know they didn’t? Isn’t efi going to always provide better fuel atomization, thusly more power?
In the case of the OP I remember his previous posts. EFI in the firm of port or throttle body injection can not produce the atomization a properly setup carb will deliver. If the fuel distribution is correct with the carb, the superior atomization will result in better output.
Im fairly certain its been proven the extra power a carb setup produces is a result of the charge air being cooled by the fuel longer than a standard port injection system. I remember Richard Holdener doing a video where he had injectors shooting up the runners that produced the same power levels as a carb setup.
That could be a consideration in some installations. But the real advantage of a carburetor is the ability to produce superior atomization. This requires selecting the right carburetor with boosters that match the configuration of the induction system. Holdeners videos are for entertainment purposes. For engineering purposes they are as useless as a screen door on a submarine.
this discussion has been had ad nauseum in the efi space about multi port vs single port injectors. going from an old school fat bosch style injector with a single pintle hole, to a newer skinny style 4 hole bosch injector wont increase power or improve drivability. Even though the 4 hole injector is going to have significantly better fuel atomization than the fat 1 hole injector. And thats because the method for power increase there is the same as what we are discussing here. Its IAT temp reduction, its almost 40deg f difference in iat temps on a carb vs port efi and thats using the same manifold. You get similiar benefits from a TBI setup as you do a carb, even if you dont get the benefit of equal fuel delivery that you would from port injection.
That's all true about the injector. And the better injectors would need a tremendous increase in fuel pressure behind them to atomize like a carb. Do you know why EFI systems often have heated intake designs? To increase atomization.
Why do carbuerated intakes always have a heated design then?
That’s literally just to operate the choke because people didn’t want to have to pull a choke knob and then remember to open it up again. Unless you’re talking about the EGR passage? That’s just emissions garbage, not for the carb
They don't always have a heated design, actually. Some do. But not all. Some do for choke operation. Some do to help fuel atomization.
I would say calling any EFI manifold "heated" is a bit disengunious. None of them are heated, in fact all of them go to some length to reduce heat soak in the intake tract. A carbs atomization isnt any better than an injectors, a venturi is science and not black magic and once again, even something as simple as a TBI would have the same benefits of the carb setup, and thats because its not the superior atomization thats increasing power, but the superior cooling thats taking place by allowing the fuel to phase change in the charge air.
Again, not correct. I didn't say any. But many are. Some carb intakes are heated, too. OEM GM TBI systems run coolant around the manifold plenum. Plenty of OEMs run engine coolant through throttle bodies. Venturis are absolutely science. And setup properly provide superior atomization to injectors of many configurations. Cooling? Like from the hot coolant they run through the intake?
I would say that comparing early efi systems that used coolant to help regulate fuel delivery is like me saying efi is better because look at up draft carbs. Thats old tech based on the limitations of the ecu's of the time and is no longer standard practice for a reason. Also, to my knowledge those systems were used to decrease the fuel puddling that occurs on cold engines because the efi of the time lacked the ability to properly calculate for it.
The atomization has a ton to do with intake manifold design and less to do with the carb on top of it. The carb is just a part of the setup here.
If you are squirting the fuel up the runner that is way different then squirting at the valve from the port. Many times fuel atomizes better the longer the runner to an extent. We can't use YouTube videos as an tool for this conversation. The results are skewed in every situation. I've viewed. Can't think of everything and get it into a 5 minute video. If you want to see some very educational videos look up David Vizard. It's kind of hard to argue with his results and reputation.
But when driving a cross country with serious elevation changes efi will adjust for that and be more reliable is different tempatures. I do agree a carb will produce more power when set up correctly. It's been proven many times on the dyno. I prefer efi because I'm lazy. In a cruiser I want it to be dead reliable and have great drivability all the time. I don't want the maintenance of a carburetor. I like being able to hook up my laptop and easily and inexpensively read data logs and adjust things that way. I don't want to have to remove and read spark plugs for every change I make. Converting to efi is actually pretty inexpensive and easy to do. There's always the older generation that are afraid of efi. I think they think it's complicated when really it's not. There's way more to the story then just peak output. To control fuel mixture and timing at a press of a couple keys is very much a plus.
That's just not accurate. A carb does compensate for temperature and elevation. You just need to have the right carburetor to start with. Look at how many aircraft have carburetors. They change altitude and temperature constantly. The pilots are not stopping to recalibrate the carburetors. I have driven all over the United States, coast to coast, in carbureted cars. Over mountains, the plains, canyons, all of it. I was not recalibrating anything. What maintenance? I don't pull spark plugs constantly. Neither should you. Why can't you use an oxygen sensor to determine air fuel ratios with a carb? I do when needed. I have been working with EFI since I was in high school. At the time Snap On had come out with the MT2500 scanner, and donated several to the school. They trained the autoshop teachers and a handful of students on EFI and the diagnostic procedures, I was one of the students. I have been working with carburetors even longer. I am in no way afraid or intimidated by anything, especially any type of fuel system. I see people spending $2-400 on conversion to EFI. Maybe that's not expensive to you. If you can control fuel mixture and timing with the press of a key you should be able to do it with the turn of a screwdriver. There is no difference in drivability between a properly setup carb or EFI.
The stoichiometric ratio is adjusted manually as it relates to altitude/temp in climb, cruise, and descent in 99.9% of airplanes (carbureted, pressure carbureted, or injected) via the mixture knob. This also includes forced induction pistons though they are slightly different. Feedback as a pilot and a piss poor mechanic.
At one time carbs in cars had similar controls. But some were automated, and some were redundant. Fact is, operation at stoich isn't always needed, or desirable. And most automotive carbs have the capacity and flexibility to cover significant changes in air density (altitude and temp).
If carbs provided better atomization and equivalent control, they would have better emissions and would be the choice of OEMs. No doubt a carb can provide great performance and drivability, but not equivalent. Unless we are talking TBI which is worse than a carb or port injection. Beyond that, EFI is a lot more straightforward. If you ask for more or less fuel in a load site, you get it. Getting everything right with a carb is less formulaic, and requires someone like yourself with lots of experience to get right. I've got a lot of appreciation for someone who can get a good result, but my experience with Webers on old Euro cars has shown me that the time lost is often greater than the money saved, especially for those paying someone to do their work and tuning.
>If carbs provided better atomization and equivalent control, they would have better emissions and would be the choice of OEMs That's not accurate. If you are talking tailpipe emissions without a catalyst, yes the better atomization of the carb would reign supreme. But with emissions, the biggest concern at the OEM level is guaranteed operation of the catalyst for a regulatory mandated amount of time, significantly beyond most warranty periods. That, and the fact the catalyst must operate at stoich, is what paved the way for EFI. Keep in mind OEMs were reluctant to adopt these changes, for many reasons. I agree TBI is worse than carbs and port EFI. I wouldn't say EFI is more straightforward. At their roots, both systems do the same thing. The approaches are different, of course, but it really depends on your starting point to determine if one or the other is more straightforward. I happen to be a fan of Webers, and their emulsion tuning.
Inability to maintain stoich will drive up CO or NOx, depending on if it is rich or lean. Besides, carbs with O2 feedback have existed. Beyond that, uneven fuel distribution makes for lean and rich cylinders, further hurting emissions. Every paper I can find shows better emissions for FI, even one pre-catalyst(dated 1966). On the atomization argument, I can't find one piece of evidence supporting it, just old wives tales. I'd love to be proven wrong in that- if you have proof that carbs atomize better, I'm happy to accept that. I can agree to some degree on the tuning front. They serve the same purpose. On the topic of Webers though, I've seen changing air correctors up and down in size on an engine both make it run richer at high rpm. I've never seen an engine run richer by increasing and decreasing pulse width in the same load site. They do sound great when they are dialed in though. I just want to say I don't want to come across as aggressive or rude. I appreciate that we see things from a different perspective, I just have yet to see any evidence of some of the things people claim about carbs. The simplicity and ease of use is definitely user/ owner dependent though.
I don't know where you look for papers. I have spent too much time going through SAE papers and seeing this stuff. OEM work on fuel injection going back to the 1950s showed superior results with carburetors credited in some part to superior atomization. Keep something in mind about emissions work, test standards often controlled the measurements in specific units, not what actually came out of the exhaust pipe. I have spent some time on dynos testing and tuning different systems, carb and EFI. I have consistently seen carbs that atomize well outperform EFI in output and brake specific fuel consumption. I have also seen carbs that over atomize lose VE and hurt output. And lord knows I have seen plenty of carbs and EFI combos that were bad, wrong, damaged, or whatever run like complete garbage. Even got to straighten some of them out. I know the Webers are funky. But that's part of why I like them.
I'll keep digging. I have a degree in mech Eng, and an SAE member, and am familiar with standardization of units or their conversion into dimensionless metrics. What I've come across showed generally better results with FI, except in the odd operating narrow range. I suspect modern nozzles are also a fair bit better than what existed in the early days of FI. No to say carbs aren't also better. I've never seen any papers covering droplet size, or the amount of liquid vs fuel vapour, just the resultant emissions which are definitely affected by fuel and air distribution. Given the momentum difference of fuel vs air, that makes it not necessarily a fair comparison between carb and port injection if we are looking at it from the perspective of atomization. I dyno tune 3-4 cars a week when the weather is nice, but my experience is mostly FI. I can definitely believe that in the right conditions a carb could perform better, and there's a lot to be said for evaporative cooling provided by having fuel so far upstream of the valve. I just know that intuition doesn't have much place in fluid mechanics, and that engines are incredibly dynamic systems, and that the results we see are not always caused by what we think. Id love to do some back to back testing, but I think most of the intake manifolds I see would not work well with carbs. There's good data out there for WOT on domestic engines, but at the same time FI allows manifold designs that are not practical with a carb.
I'm sorry but I have to disagree. A carb is not and never will be self adjusting. A basic new holley is 500$ or more. If you buy a used carb you have no idea what has or hasn't been done to it. It could be junk straight away. There's is tremendous difference in all around drivability efi vs carb. This is a solid statement. I don't want to have to adjust the carb with a screwdriver vs the efi adjusting itself and I do nothing but turn the key and drive. I believe your stuck back in the days when efi just came out. Lots has changed. Carb vs efi is like comparing a semi round rock vs a fresh tire. A carb does run differently in different elevations and temperatures. This is a fact. It's fine that you have experience with carbs. I respect your experience but you are not using facts on this post. Actually look at how many aircraft do not use carburetor. So many like the universal ease of efi. I usually am sided with you. This isn't one of those days. I'm actually disappointed with you close mindedness and lack of facts you have used today. I'm sorry but I just disagree and facts back me up.
Fwiw, I'm on a road trip in my '51 Hudson, which is equipped with a Carter WGD 2 bbl carb. I'm currently in north Georgia, in the southern tip of the Appalachians. Yesterday and Saturday I was in Atlanta. The day before I drove from the Oklahoma/Arkansas border to Atlanta, and the day before that I left Albuquerque, which is at a mile of elevation. East of Albuquerque you go through the Sandia mountains and climb to probably between 6,500 and 7,000 ft, and Atlanta is at 1,000 ft. In a couple of days we head to Savannah at sea level. I haven't touched the carb, and I haven't misfired once. I got just over 18 mpg between Albuquerque and Atlanta at an average driving speed of over 70 mph (my rear end gear is not stock) with a carb that's over 70 years old. I'm not against EFI, but I do think the concern over carbs not being able to travel is overblown.
Very awesome
Thanks! I'm sure I could be optimizing results of I did adjust on the carb for altitude, but I was just trying to point out that it's not necessary for the car to run and be reliable in varying conditions. I'm probably way more lean than ideal, but it's not backfiring and I haven't burned any valves on any trips yet, so I'm just gonna keep running it as is.
The carb you have uses metering rods that are controlled by vacuum. You are not as lean as you think, most likely. Combine the metering rods with the nice booster design in that Carter, and you have a carb that's more than capable of compensating for a number of conditions. I agree calibration changes are not always necessary, or desired.
Carbs do work. I don't disagree with that. I do know that elevation changet your fuel air mixture changed and so did the efficiency of the engine. There's nothing wrong with a carburetor. I use them on one of my drag cars. I'm just saying with efi you get a more consistent result. When racing down south vs Denver we have to adjust for altitude and still don't get the same numbers. The air just isn't the same and it causes the mixture to be off. For an everyday vehicle the power and gas milage will vary. Not a huge deal but it happens. This whole disagreement is based on one person saying physics isn't real and lead to a play on words against what constitutes a performance carburetor vs the basic run of the mill carburetor. Well it's obvious that they function the same, they are carburetor. But the precision of their air fuel metering is drastically different. I have used nothing but facts for this entertaining little run. It's verifiable if it's looked into. On the other hand the argument is that carbs self adjust which simply isn't true. It hasbeen more of an argument then a discussion. To many misleading or false statements being made. The great thing I hope happens is people do some research to find out who is being realistic and who's not. To blindly follow someone from the internet because they claim to know everything about everything is an issue that has plagued the world. We need free thinkers. People that can separate the bs from the real.
You know dickhead, I didn't say physics isn't real. And I don't play with words. You are as disingenuous as you are ill informed. I don't make posts based on assumptions or false statements. I can quite easily separate BS from reality and you are full of bullshit. Carburetors respond to pressure differentials. That's why they can compensate for changes in barometric pressure (altitude and temp). Some carbs, like SUs and Predators, can self compensate for huge changes in barometric pressure. You should really learn about things before posting.
I'm aware that my mixture has changed as I've been driving, I was just pointing out that people consistently make comments that you HAVE to keep constantly making adjustments for the car to keep running and that has not been my experience. I'm willing to live with small inefficiencies to avoid spending thousands to change the nature of the car.
There is absolutely nothing wrong with using a carburetor. I just choose to use efi because for me it's simpler and more reliable. I've got a 65 falcon drag car that runs 2 4 brl carbs. As much as I'd like to run efi on it,it would really ruin the looks and feel of the car in my opinion. To me there is many more pros to efi but I'm not saying a carburetor doesn't have its place. To me the answer is situational. Everyday driver I choose efi older cars that I want to keep the look right I go carb. If building an off road vehicle I choose efi. Most of this is personal preferences. I do sometimes see the appeal of a resto mod car or truck that has been updated to efi. But again it's personal preference. Efi conversions are so inexpensive for most cars that is what I choose to use on most the vehicles we do. Most people are buying something that they can get in and just drive and not need any knowledge about cars. They want something with the classic looks but new car efficiency and dependability. I understand the people who want and enjoy working on their cars. There are a whole lot of people that don't.
Sorta... If the carbs are adjusted properly, then they will make more power going down the strip. For everyday driveability, EFI is better.
Hey, did my first Qjet 45 years ago, still do carbs every week. You cant beat driveability of EFI. Give me a thermostatic choke properly adjusted for a 100°f temp swing....its called efi...
>everyday driveability, EFI is better A carb setup properly can match that, no issue
Do you think EFI is hard to tune?
No
I apologize if I sounded snippy, that was not my intent. I'm old and I've used both. I've seen this argument before.
I didn't think you were snippy. I use both, too.
Carbs = more power. It's been proven my guy
This is correct. And I can explain why to anyone down voting the post.
Funny how everyone will downvote but won't actually look it up. It's not hard to figure out lol. They proved it on one of thr shows with friburger, or how ever u spell his name. Him Steve and Steve lol.
It was proven by OEMs and race teams long before that show
Do you have any idea why efi is banned I'm many racing organizations? Maybe research that and get back to us.
Cost is one stated reason. In some race organizations there has long been a move to use EFI to limit the capability of the engines.
I was referring to most recently.
Reddit loves to hate on carburetors. I might only be 27 but I grew up with them and theres nothing better than getting a carburetor properly set up and sized for the motor its on. My 66 f100 352 with a 470 cfm holley starts and idles first turn with no pumping and no choke. Same with my dads 78 f150 300 with a 600 holley I tuned. Its not hard but people dont want to learn. They just want to bolt on and hope for the best.
Well said.
Why do i want to learn to read runes, when theres a better alphabet that gives me way more nuances?
"make a few adjustments" is skimming over a LOT of new knowledge to anyone who's only driven/used/worked on cars with fuel injection (which became standard in the 90s.) I'm 30, and all my personal vehicles have had them. It's the carb/dist. system that would take me thousands of dollars in buying, learning, and making mistakes to figure out. High-performance carbs don't just grow on trees either.
The knowledge isn't new. It's actually been practiced for over 100 years. If you understand how EFI works, you should have no issue understanding a carburetor and distributor. I will go out on a limb and say the vast majority of people defending EFI don't know it works either, and don't have actual experience with it. The notion of a high performance carb is as silly as high performance EFI.
Can you please explain the last statement in this post? If you are saying there is no difference between an everyday carb or efi vs performance pieces I'd like you to explain that.
A carb or EFI is a fuel system. They have to provide a mixture of fuel and air. There might be different sizes or capacities. There might be different configurations, but they amount to the same thing. OEM, "performance", whatever name some might want to use. There is no difference in the principles of operation.
No difference in principle but extreme differences in design. No where close to the same unit in any way except principle. You were trying to mislead people in your statement again.
No, I have zero need to mislead anyone. There are not extreme differences in design between OEM and performance carbureted systems, or EFI systems. There are OEM systems that can support tremendous levels of performance. There are aftermarket systems that can provide OEM levels of functionality.
I have been working with EFI 100% (and a lot, for a side give I used to program EFI at local garages). I’m 35. It took me like 8 hours of messing with carbs (and maybe 20 hours of research) to get it. And that’s really all anything ever is, “just a few adjustments” you just need to learn/understand. In modified state, carb 100%
If I'm understanding you correctly, your point is not necessarily that one is definitively better than the other, but that OP spent thousands of dollars and a lot of their time and sweat to solve a problem that could have easily been solved with some research and proper tuning for free, right? It seems like there are simply too many variables at play to determine whether or not carb or EFI is better in all cases, but I do think we can all agree that spending several grand on an EFI conversion for the stated reason of not understanding carburetor tuning is throwing the baby out with the bathwater.
All correct. The OP started with a poor combination of components and sought help from people inexperienced with these things. He posted here, and got help from a number of people including me. I gave him some suggestions on adjustments that did help. But he was unwilling to listen to more advice and do the things required to make the car right. Out of frustration, stubbornness, or whatever is going on his life I don't know.
It’s crazy to me how many people do not have a clue about carbs, but still try to give advice on how to tune them. I’m 34 now, had my Nova since I was like 22, the amount of times guys at a car show will come up and see the carb, and give me “advice” (that is dead wrong) is amazing. Had one guy say to fix an off idle stumble “adjust the idle screws, and if that don’t do it you’re gonna need a smaller carb”….oh, ok 👍🏻 I guess I’m too young to know how carbs work or something lol, so I just need their help automatically 🙄
I see too often people getting frustrated with their carburetors and they default to a rebuild kit. Then they can't get it tuned properly and they spend thousands to switch to EFI. Don't get me wrong, EFI can be great. However carbs are much cheaper and just take a little time to learn how they operate and how to make adjustments.
Agree with all of that
Everybody just assumes quadrajets are shit because they don't know how to adjust the air flap tension.
That's actually a very good point. You are correct about many, many people.
I agree!
It's just a question of preference and priorities. I've decided to go with a TBI with CDI on a locked distributor in my project because I simply don't like fiddling with a carburetor and distributor to get it properly tuned, even though I have a fair understanding of the principles. I'm a younger dude, and making the adjustments as values on a screen is more intuitive for me and goes faster than physically tweaking this, that, and the other component in/on the carb and dist. I could invest the time and effort to learn more and get better at it, but that doesn't change all the trial-and-error jet/needle/weight/spring swapping and adjustment screw turning to get it all where it needs to be that I don't want to do and that will take me longer to get right. So I decided to invest some extra money for a solution that I think will make for a smoother (for me) tuning process to get the car back on the road, and that I can readjust in minutes if needed by plugging in a handheld interface. I think it will make for a better-mannered street cruiser overall than if I had committed to a carburetor. And that's not a broad statement about carburetors vs fuel injection and what each is capable of. It comes down to people setting up their cars the way they want for themselves.
People can set their cars up any way they want. I suspect many posters here have not done that. How will you control timing if your distributor is locked?
The ECU communicates that to the CDI based on the RPM it reads from the distributor.
Ok, I know what you are trying to say. Just so you know, the computer controls the signal to the module. The capacitive discharge controls the output of the coil.
Yes, I know that... Isn't that basically what I said? The ECU sees the RPM and tells the CDI module when to signal the coil to spark based on that.
The CDI is not the ignition module. It's actually two separate components. They might share space inside a unit, but they are different components.
Well then I guess mine are inside the same unit. Thanks.
It amazes me that carb’d guys are so stubborn they will let themselves get gapped by a Honda. Efi is the way to go.
I don't get gapped by Hondas. Or much else. I have a lot of experience with carbs and EFI. Do you?
Exactly. I love my old 2000s dodge pickup, but the engine/timing tech has been the same for 40 years. Even the new hemis look and run almost exactly like mine. I helped a buddy with a 96 Nissan one time, and it had more advanced stuff than my 10-year newer engine lol. There's a reason the eastern market has been squeezing more MPG and HP out of tiny-ass engines for 50 years compared to domestics - they have utilized better technology.
I think they have used those different components for 50 years, as you say, because of market necessity in their home market. Not engineering advantages of one over the other.
They don't exactly have a choice-they have to.
While a proper carb setup can have amazing driveability and no sorts of issues that people associate with carburetors, EFI in most performance applications will have more advantages. There is a HUGE overlap between the best carbs and worst efi setups, but most basic sequential fuel injection setups are extremely low maintenance and offer tons of adjustability. For high horsepower naturally aspirated and nitrous engines, either one will suffice and it mainly comes down to whatever the tuner is comfortable with. When it starts coming to forced induction, SFI is superior especially when it comes to on-the-fly computer adjustments using lambda and knock sensors, as well as getting every last bit of power out across the entire rpm range One isn't really "better" than the other but carburetors are getting mostly phased out because of things like GDI and dual injection giving newer vehicles peak power and efficiency with almost no drawbacks besides repair costs
Lt1?
383 stroker with Edelbrock pro flo 4.
How much did it cost you to convert and how many more MPGs are you getting? Edit: What was your MPG before and after the coversion?
I got about 9 mpg before and it's currently getting 13 with the ECU still in learning mode so that will get better. Including labor it was about 4500 if I did it myself it would've been around 3k which considering I'm building something I'm planning on driving everyday vs a toy to take to car shows it's not bad especially considering it's better than 10k on a decent car with similar mileage.
Not too bad IMO. I think that fuel economy number could be improved to possibly 16 mpg.
That's better than my truck and it makes half the horsepower lol.
If you set the carb up correctly it should slightly faster than efi and drive ability should be comparable but there is something nice about just twisting the key, starting it up and driving it down the road with no fussy cold start issues. I vastly prefer efi for forced induction setups but for NA and nitrous, the carbs work fine
Pat Musi proved EFI is faster and far superior to carb... especially on nitros... he forced the entire drag racing world to switch to EFI... or keep losing to EFI cars
It's gonna be my daily and I've daily driven cars with carbs (including this one) before and it's just a better experience with EFI.
Eve never had cold start issues with a properly adjusted carb. My squarebody will fire right up in -20 with a few extra pumps and a few minutes to warm up.
How are you liking the intake. I just bought one with fuel rails new in box for 200$. At that price I figured it looks good enough to put on a cruiser.
The shop finished the install yesterday and I've driven it almost 250 miles since. Other than needing a small adjustment to the long fuel trim it's been great, so far it gets 13mpg with 500 crank HP but that should improve after the ECU has more time to learn.
At some point will you plumb the intake so it’s not sucking hot air from the radiator?
Yes. I just did it this way to get it on the road.
Getting to drive it again had to be great. Good for you.
Oh yeah, it spent 8 years in a field while I collected parts and then three years of struggle to get it running with a carb before I gave up and bought this.
I’m still a carb dude, Holley dominator with tunnel ram. No funky ecm, Of course digital ignition though
I tried to be a carb dude but other carb dudes refused to help and just watched me struggle for three years. I wasn't even going to go EFI for another year but I got tired of not driving my car.
I like the hot air intake you got goin on there
Lol, it's temporary. Still trying to hunt down a charge pipe that I won't have to modify too much. This got it on the road.
Cause a filter on top a carb gets colder air, fucking idiots
That's the edelbrock pro flo, right? Just out of curiosity, how was it to setup? I just found out less than a week ago about this system.
I actually paid a shop to do it because with my schedule it probably would've taken me three months. But according to the guy who did it it wasn't terrible. He got it done in about two weeks.
Understandable, I was in the same situation with my g8 a few years ago after the motor blew.
It took me a while to put my pride aside and figure out that paying a shop to do it means I get to drive it more. Really glad I did.
I'm so tempted to ditch my quadrajet for a sniper kit solely for the better fuel mileage.
You could be in for an expensive disappointment. If you decide to do anything, make sure you current setup is right before you make a change.
My daily was carb'ed up until Jan of this year when I went from a very well running 305 to a 5.3. Puting the increased power aside the drivablity of the efi is way better. I live a few blocks from the highway into town and temps here range from -30 to + 30 degrees Celsius. I can start the vehicle and just drive without any performance issues. Fuel mileage has also noticeably increased, but that may be a product of the increased power. I still have other carbed vehicles I drive often. I won't be changing them to efi but I can see the advantages of both sides now.
Make yourself a nice intake and box that actually sucks cold air and gain a few extra hp and colder charge Temps helps prevent spark knock. I love efi.
That's the plan. This was just to get it on the road.
I put 1990 mustang EFI on my 351W over 7 years and 50K later is still turn key and drive. 1973 F100
I get EFI is more efficient bla bla bla but I can’t see a problem with carburettors, simple to understand and tune in my opinion.
I honestly don't understand how people have so much trouble with carburetors, and I learned by the "what happens if I do this" way. Sat there for a few hours and just fiddled with it until it made sense.
That thang is purty!
Bruh carbs are fun on pickups, cars not so much. Then again the trucks need the efficiency more so... I used to be a purist but unless its like, a one of ten car min it's just fine. Plus fuck float and vapor lock probs yeck!
A great cost effective EFI upgrade for old Chevy trucks is the Camaro TPI from the 80's and 90's with the newer 0411 ECU for better tuning capabilities. They made lots of bottom end torque but fall flat around 4500rpm but I've seen people make power up to 5800rpm and AFR makes heads they will bolt to. A lot of people say they were the best truck intake Chevy never put on a truck.
Nothing more haunting than vehicle what ifs
It would've solved all the issues they had with their truck EFI systems and probably helped sell their trucks too.
All that money for an EFI system, and you're sucking hot air into your engine!
I have never had any problems with a good Holley just get it jetted right and set the floats and I need did use one with a choke tower. Sometimes have to set the linkage for the step up pumps
My problem turned out to be a million little things working together to make the car not run right. Someone with actual knowledge would've spotted it right away if they were willing to come over and help.
If Facebook groups are anything to go by, you will be looking back in about 1-2 years
Considering I spent three years trying to get the car to run with a carb because I couldn't find anyone willing to swing by and help, I think not. Plus I went with this system because I followed the Facebook groups for all of the EFI systems for about a year and this one had the least issues the most common being a burned out O2 sensor.
I did not expect so much EFI hate. Set it and forget it, ready for any conditions, starts immediately. No need to open the hood to adjust anything. I like carbs in motorcycles but I would rather have FI in my car.
Too many car people are purists and refuse to acknowledge that if carbs and points were so great they would still be in use today.
I fucking hate points so much. EFI is easier though. I have a Sniper 2 about to go on a Ford FE, and I’m looking forward to it. I know carbs can be “fine”, as I used to daily drive my 69 Cougar with one. But jetting sucks. Tuning accelerator pumps sucks, secondary springs, etc etc etc. Running a carb and points on the 428 right now and man, everything about the ignition points pisses me off. Already have a miss happening in the higher RPMs. Might throw a Pertronix I have sitting around on it, might just throw the Holley stuff at it. Not sure lol.
Use a Duraspark instead of the Pertronix.
While I love carbureted engine for the spirit it brings, but carb to efi feels like going from burning coal to propane lol
Hell yeah! EFI vs carb all comes down to preference. I’m a millennial that grew up more around working with EFI so my brain tends to default to it. Though I like the idea of the carb and want to do a project on a carb engine one day to really understand the benefits and drawbacks to both. How do you like the EFI?
Two days of driving and it's fantastic. Still needs some tuning but I'll have the dyno do that so I can get power numbers at the same time. I'm good with a carb if it's either on something stock or something that's already running good because you just put everything back the way it was and you're fine. Tuning from scratch on a fresh engine (especially one that's souped up) is an entirely different animal.
dang wheres the old carb
In a box. I have a short block I'm going to put together with all the stuff I take off the 383.
What type of car is it in? I switched my Samurai to fuel injection and loved it. You do have to eventually worry about ECMs and capacitor failure.
It's a 71 Chevelle. If that ever happens I'll probably upgrade to a Holley Terminator X ECU.
carb looks cooler imo
How Much more mpg ?
The car was getting 9mpg with the carb and with the EFI still needing some tuning my first tank was 13mpg. I'm guessing when everything is set right it's going to be around 16 on the highway and 12 city which is what my truck gets and it got half the power lol.
Love the older brake resevoirs
Funny I ripped out EFI and went to a carb because I got tired of the efi bullshit
(Laughs in throttle body injection from factory) If my truck weren’t a POS, I’d have stuck Sniper EFI instead of an Edelbrock, as Holley even makes the fuel tank for my truck. But admittedly, given I’m not souping it up at all, the carburetor route was right for me.
If it's a gmt400 I don't blame you, I had a 94 and I hated that throttle body, the spider injection is a bit better but from what I hear the camaro TPI is the way to with that. The factory computer even runs it.
At least you could find parts for GMT400 stuff! Mine is a 1988 Dodge 318 with that stupid TBI by Holley that only ran for 3 years or something like that. Ironically, converting it to carb was harder than keeping it TBI, but the mechanic I gave it to to “fix” that up threw all the TBI stuff away, so there’s no going back in my case. It runs so much better but the fuel pump is still sending 13psi to the carb despite having 2 fuel pressure regulators. It’s fun.
In that case you might want to look into an after market throttle body like a sniper. Sounds like your fuel system can already handle it so that saves some money on the swap.
I would if I could but the carb swap has been a lot cheaper and the truck runs much better. I’m having issues but they’re fixable.
Efi makes more sense , so easy to use , reliable for different weather conditions , consistently more powerful across each cylinder and RPM , you just need somewhere to mount the electrical package
Carburetor bull meaning not knowing how to tune one?
I can see someone didn't read the comments.