turbo size opinion

[Sr20detNESS]

I am looking to upgrade my turbo soon with upgrades such as 555cc injectors (minimum), z32 maf, and an aftermarket intake system. My question is what would a good size turbo be for this setup as far as compressor housing size, turbine housing size, trim. the amount of horsepower the turbo is good for is not a factor, the more the better (the only upgrades i will have is what i listed and full 3" exhaust and will be running stock boost) Also do you think i will need to upgrade any other parts right away with this setup as far headgasket, cams etc.

[Nismo_Freak]

I have a GT25R that will push 400whp. I'd sell it for $475 shipped if you wanted it.

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[95lstegman]

if you're going to run stock boost, why are you upgrading MAFS, injectors, or turbo at all? i mean even upgrading the stock i/c to a really nice front-mount won't show hardly any gains at stock boost (although any high-performance driving over ~10 seconds will be better thanks to no heat soak). and if you're going to upgrade MAFS, injectors, and turbo, why run stock boost? just pick up a nice intercooler with those items and crank it up (be smart here, and get it tuned as well!).

[Sr20detNESS]

Yes i know i have to tune my ecu and why should i not upgrade if im gonna be running stock boost? with a turbo bigger than the t25 at the same boost you will feel a difference. A larger turbo running the same boost as a smaller one is gonna be more powerful and i am going to upgrade my injectors and maf because i will need to

[95lstegman]

the point is that if you're only going to run 7psi, the stock T25 isn't that bad because it spools so quickly. sure, you might get 10whp out of a bigger turbo, maybe even 15whp, but at what lag cost? exactly. area under the curve, my friend. be careful. some larger turbos will flow a lot of air and will trip the fuel cut even at 7psi.

and if you're going to get full fuel and engine management upgrades, why stay at stock boost? i'm not understanding if you want to upgrade the turbo then get the other stuff then up the boost, or if you want to upgrade everything and still keep stock boost.

[D1 guy]

basically a waste of money. Why spend 2 or 3 grand for 15-20 hp.....If youre gonna buy all that, then you might as well run 17psi or so and have a party with it. You can run 15 or so reliably. Whats the deal with wanting to keep the stock boost level?

[namwons_240]

Exactly why would u want to upgrade to a larger turbo and stay at 7-8 psi when u can get a $10 dollar manual boost controller from ebay and turn the stock turbo up to 11-12 psi and get better results and like nill for lag. And it does matter what size turbo u buy does matter, not 'the more the better'. U want a turbo thats with its efficiency range of the horse power goals your looking for or else its a waste of money to buy a 1000hp turbo and run it for 250hp. Huge waste of time and money. Seems like u dont know what your goals actually are. Till u decide then get the corresponding parts to meet your goals, not just get parts and throw them on the car.

[95lstegman]

Seems like u dont know what your goals actually are. Till u decide then get the corresponding parts to meet your goals, not just get parts and throw them on the car.

hey, he can go ahead and buy stuff out the ying-yang. then when he realizes what his goals are he can sell it all for used prices and we all win when somebody parts out a setup.

[98silvia]

yes, i would like to know is a T50 turbo good for the sr, and how much hp will that turbo push out. i always saw the T50 turbo kit sell it on ebay, so i was wondering is that even a good turbo kit for the sr. thanks

[95lstegman]

well, it's a truck turbo, like the T3/T4, so it's probably not exactly cutting edge, or really that great of a car turbo. it's also HELLA heavy. it's HUGE. my guess is it would be basically worthless for an SR. if you ever had enough exhaust gas flow to make it work, it probably wouldn't be worth the trouble of buying it, custom fabbing all the lines and hoses and manifold and downpipe, not to mention cutting a huge hole in the hood to fit it. ad when all is said and done you'd still have a sucky turbo with hella lag and mild power for the amount of lag.

[namwons_240]

Actually Garrett/Airresearch designed these turbos 30-40 years ago for areomotive use. Just happen to work great in internal combustion engines.

[95lstegman]

Actually Garrett/Airresearch designed these turbos 30-40 years ago for areomotive use. Just happen to work great in internal combustion engines.

were you able to find a compressor map and turbine map? i wasn't. i just figured after looking at pics that it is probably worthless. big mismatch, which will make it spool all at once instead of delivering linear boost up to the point of full boost, and the design is SO old. fluid dynamics has come a long, LONG way since the time this thing was designed.

[98silvia]

ok, so can you tell me what is the best set-up for the sr, i really want to find out, i got the 264cam in/out, retainer, valve springs, intake manafold, 70mm throttle body, rocker arm stopper, and now i am looking to get a good set of piston and rod, please give me some info what kind of piston and rod should i get. And what kind of turbo should i get for the sr, i am looking to spend around 2000-3000 for the turbo set up unit. my goals is to get some where around 450-500hp. please let me know what should i get, thanks.

[95lstegman]

a properly-sized T3/T4 would do the trick, but with more money you could pick up a GT30 or GT35 BB turbo and have a bit better response and spool, although with a turbo this big, lag is going to be an evil monster and response probably isn't necessary as it will be too big to drift or anything. pretty much drag only.

i saw a guy running a GT40 or so on his SR buildup. i think it was GT40 or GT42. crazy sh** man. no boost until about 5000rpm, full boost a little after 5500rpm i think. he made 394whp at 12psi when first tuning for low boost. now keep in mind that's a sleeved and fully built block and FULLY built head, so we're talking ~30psi in the future. mmmmmm . . . the SR can definitely make big power.