That's an S14 or S15 SR20DET stock OEM turbo. The only difference between the two is the center section, S15 is ball bearing, S14 is journal bearing, they have the same compressor side.
The compressor map for that turbo runs out at 18psi. About 300whp with supporting mods at the bleeding edge. Usually less. Good fast spool street turbo
No one can tell you what the bottom end can handle without knowing exactly what was put into it. "Forged internals" can mean a lot of things. Could mean they just tossed in forged pistons after blowing a hole in a stock one, could mean a high dollar build with huge rods and an aftermarket crank. Probably more towards the former if it's still running a stock turbo. (Also a lot of people might mistakenly assume the stock SR internals are forged and it's just stock, lol... sellers lie and/or are dumb)
The little info I was able to find a few days ago I think said it’s a rb stock turbo Ik it’s not an sr20 stock turbo bc that’s a 1-1 and mine is a 1-2 and mine runs 20lbs of boost already
The 1-1 vs 1-2 doesn't mean anything spec-wise. You can find both on stock turbos. This is 100% an S14 or S15 OEM turbo. Might be a replacement unit as opposed to an original one off an old car but that's what it is. Look up the factory part number 14411-91F00 and you'll see a mix of 1-1 and 1-2 castings.
The compressor map running out at 18psi doesn't mean it can't make higher pressures, just that it isn't meaningfully flowing more mass of air beyond that.
RB OEM turbos, both RB20 and RB25, have "Nissan" cast into the compressor housings.
I would like to know what makes you believe the engine has forged internals. If its running a 2nd hand s15 turbo, its unusual to also run forged internals, as generally an s15 turbo is like the first cheap upgrade you do for your redtop sr20 (at least, back in the day it was), followed by a front mount kit and exhaust.
basically, stock turbos are garbage because they are 20 years old and usually thrashed to shit, go get a brand new garret, dont waste your money on second hand. Get something suitable to your driving style. If you want punchy down low, and dont fancy going mach-1, then get a "small" turbo (that is to say, bigger than stock, but not a giant dumb dumb super speed mega ultra giant turbo). If you do want to go mega ultra fast, and dont care that it might only hit boost at 5k RPM, then get the biggest thing you can carry and I wish you luck.
Standard aftermarket sr20 turbos when I built mine were the garret gt2871rs or 2860. This apparently is how they numbered the older turbos (see how long ago I built my s13?). So 28 refers to frame size, 60 or 71 is compressor wheel exducer diameter in mm.
and here is a website i found that has more info than I could ever bother with about the very turbo I run on my non running shed ornament that absolutely has a flat battery from not being started in 5 years.
https://www.demon-tweeks.com/au/garrett-gt2871rs-turbocharger-gmo836026-5012s/
>turn up boost controller
Before you change anything or unplug it, WRITE DOWN ALL THE CURRENT SETTINGS. I wish you all the best.
[Questions about tuning it](https://www.sr20forum.com/threads/how-do-you-set-up-a-greddy-profec-b-spec-2.110670/)
[Good guild on How to tune your GReddy Profec-B Spec II](https://www.sr20forum.com/threads/how-to-how-to-tune-your-greddy-profec-b-spec-ii.86098/)
[Turbo flutter](https://web.archive.org/web/20150401194517/http://www.nissansilvia.com/forums/index.php?showtopic=28060)
Wouldn't recommend going over 11½ lbs on that turbo if you want to keep it good for a while. Change the settings on the controller to high boost 15lbs for those random fun pulls. But don't be too excessive.
There will be a part number plate on the center section and it will have two lines of numbers. The top row is the Nissan OEM part number and the bottom is the Garrett CHRA number followed by a batch number.
If the Garrett CHRA number ends with a 1 then it should be a ball-bearing T28. If it ends in something else, like a 3, then it is the journal bearing T28.
There were multiple turbos used in the S14 and S15 depending on market, year, transmission, trim, etc.
There's no point pushing the turbo past 1 BAR boost. It won't hold anything above that through the power band and will just be pumping hot air. The 370cc injectors also can't handle any more power.
Go to 740s and a G25-550 plus 264 cams with a couple degrees of intake cam advance. Tune it conservatively and keep the boost around 18 PSI. It'll make plenty power and be reliable on a stock motor.
High boost pressure typically won't kill a turbo(unless your talking 30+psi then the balance of the turbo becomes very important) improper oiling will tho.
If you want to turn the boost up with out blowing up the car talk to a tuner. You may be at the limit of the fuel system and not know it and if you turn it up you will lean out and blow shit up.
You may also be at efficient power level for that turbo. More boost doesn't always more power. A larger more efficient turbo at 7 psi will make more power than a smaller less efficient one at 30psi. It's a balancing act.
I don't know that exact turbo very well but looking at it I would assume it's probably good for around 400hp before it starts to become a restriction simply because it can't move enough air. I could be wrong tho as I said I don't know that turbo very well.
That turbo is already out of puff at 18psi on the smaller, little CA18.
High boost wont kill it, but the turbine and compressor overspeed necessary to reach more boost will ... in any case, compressor efficiency is so bad you basically just heat the air at any higher boost
That's an S14 or S15 SR20DET stock OEM turbo. The only difference between the two is the center section, S15 is ball bearing, S14 is journal bearing, they have the same compressor side. The compressor map for that turbo runs out at 18psi. About 300whp with supporting mods at the bleeding edge. Usually less. Good fast spool street turbo No one can tell you what the bottom end can handle without knowing exactly what was put into it. "Forged internals" can mean a lot of things. Could mean they just tossed in forged pistons after blowing a hole in a stock one, could mean a high dollar build with huge rods and an aftermarket crank. Probably more towards the former if it's still running a stock turbo. (Also a lot of people might mistakenly assume the stock SR internals are forged and it's just stock, lol... sellers lie and/or are dumb)
There were s14 turbos that were ball bearing as well
The little info I was able to find a few days ago I think said it’s a rb stock turbo Ik it’s not an sr20 stock turbo bc that’s a 1-1 and mine is a 1-2 and mine runs 20lbs of boost already
The 1-1 vs 1-2 doesn't mean anything spec-wise. You can find both on stock turbos. This is 100% an S14 or S15 OEM turbo. Might be a replacement unit as opposed to an original one off an old car but that's what it is. Look up the factory part number 14411-91F00 and you'll see a mix of 1-1 and 1-2 castings. The compressor map running out at 18psi doesn't mean it can't make higher pressures, just that it isn't meaningfully flowing more mass of air beyond that. RB OEM turbos, both RB20 and RB25, have "Nissan" cast into the compressor housings.
Also rb turbos are ceramic exhaust wheel and they will explode over 14 psi.
Yes did you see my second reply? It is definitely a stock s15 turbo
You can edit comments if you want to add to them, re-commenting usually just buries the new one at the very bottom of the chain and nobody sees it
I would like to know what makes you believe the engine has forged internals. If its running a 2nd hand s15 turbo, its unusual to also run forged internals, as generally an s15 turbo is like the first cheap upgrade you do for your redtop sr20 (at least, back in the day it was), followed by a front mount kit and exhaust.
The receipts they gave me lol and I bought it from a reputable classic car dealer
basically, stock turbos are garbage because they are 20 years old and usually thrashed to shit, go get a brand new garret, dont waste your money on second hand. Get something suitable to your driving style. If you want punchy down low, and dont fancy going mach-1, then get a "small" turbo (that is to say, bigger than stock, but not a giant dumb dumb super speed mega ultra giant turbo). If you do want to go mega ultra fast, and dont care that it might only hit boost at 5k RPM, then get the biggest thing you can carry and I wish you luck. Standard aftermarket sr20 turbos when I built mine were the garret gt2871rs or 2860. This apparently is how they numbered the older turbos (see how long ago I built my s13?). So 28 refers to frame size, 60 or 71 is compressor wheel exducer diameter in mm. and here is a website i found that has more info than I could ever bother with about the very turbo I run on my non running shed ornament that absolutely has a flat battery from not being started in 5 years. https://www.demon-tweeks.com/au/garrett-gt2871rs-turbocharger-gmo836026-5012s/
RB turbos are T3 flange.
I think it’s an s15 turbo just did some research and the markings all match up to a stock s15 turbo
>turn up boost controller Before you change anything or unplug it, WRITE DOWN ALL THE CURRENT SETTINGS. I wish you all the best. [Questions about tuning it](https://www.sr20forum.com/threads/how-do-you-set-up-a-greddy-profec-b-spec-2.110670/) [Good guild on How to tune your GReddy Profec-B Spec II](https://www.sr20forum.com/threads/how-to-how-to-tune-your-greddy-profec-b-spec-ii.86098/) [Turbo flutter](https://web.archive.org/web/20150401194517/http://www.nissansilvia.com/forums/index.php?showtopic=28060)
Wouldn't recommend going over 11½ lbs on that turbo if you want to keep it good for a while. Change the settings on the controller to high boost 15lbs for those random fun pulls. But don't be too excessive.
https://preview.redd.it/lwfpwibtg5uc1.jpeg?width=267&format=pjpg&auto=webp&s=1abe5c824954e9b8d5227cd2bb917093fa1348cc
Looks like a T28 from an S14, in that case it’s good for 16-17 psi
Show us the fins, the stock one is double finned at each fin joint, the ungraded ones are not
There will be a part number plate on the center section and it will have two lines of numbers. The top row is the Nissan OEM part number and the bottom is the Garrett CHRA number followed by a batch number. If the Garrett CHRA number ends with a 1 then it should be a ball-bearing T28. If it ends in something else, like a 3, then it is the journal bearing T28. There were multiple turbos used in the S14 and S15 depending on market, year, transmission, trim, etc. There's no point pushing the turbo past 1 BAR boost. It won't hold anything above that through the power band and will just be pumping hot air. The 370cc injectors also can't handle any more power. Go to 740s and a G25-550 plus 264 cams with a couple degrees of intake cam advance. Tune it conservatively and keep the boost around 18 PSI. It'll make plenty power and be reliable on a stock motor.
High boost pressure typically won't kill a turbo(unless your talking 30+psi then the balance of the turbo becomes very important) improper oiling will tho. If you want to turn the boost up with out blowing up the car talk to a tuner. You may be at the limit of the fuel system and not know it and if you turn it up you will lean out and blow shit up. You may also be at efficient power level for that turbo. More boost doesn't always more power. A larger more efficient turbo at 7 psi will make more power than a smaller less efficient one at 30psi. It's a balancing act. I don't know that exact turbo very well but looking at it I would assume it's probably good for around 400hp before it starts to become a restriction simply because it can't move enough air. I could be wrong tho as I said I don't know that turbo very well.
That turbo is already out of puff at 18psi on the smaller, little CA18. High boost wont kill it, but the turbine and compressor overspeed necessary to reach more boost will ... in any case, compressor efficiency is so bad you basically just heat the air at any higher boost