How much PSI can i push out of a GT28 if twas High Flowed

The GT28 is a great turbo and spools and makes good power, it will run 20psi but it will be out of its effeciency range and i would sugest a turbo change if you are going to be running 20psi as you will make more power in the long run.

try looking at something along the lines as a GT2871R it will have no problems running 20psi as its right in its effeciency range and one with a .86 rear will be little bit laggyer but the hondas high reving nature will more than make up for it.

as the for SR20 my mates running 21psi through his with a massive turbo kit making 386hp ona a stock motor and tomei metal head gasket.

i think the GT28RS is a high flowed GT28 from factory if i'm not wrong, not sure if your gonna get much more out of it. But i'm pretty sure the RS can run at 20PSI, just may need earlier rebuilding, due to the higher stress.

But then i always though that the amount of boost did not always equate to the same power, i.e a larger turbo will have less PSI than a smaller turbo making the same power.? correct me if i'm wrong.

I'm currently also looking at a bigger setup also and am going GT2871r with a .64 rear (trying not to get too laggy). I've only just got the manifold setup the way i want ( i still wanna retain a/c)


i've noted that on alot of high boost setups it comes down to the boost controller not being able to hold down the PSI. When running larger amounts of boost a good ebc is critical also to how the turbo will flow. if the boost controller is not up to it it sometimes feels like the turbo is maxing out and running out of puff. A friend of mine had this problem.

ANyway i'm still earning this stuff also so keep us informed how you go.

Hmmm i think i might just push it to 16 psi for now. I've recently just been sponsored by a new performance import company called 'Hiro motor sport' and they can sell me a garret gt30r for $1400 or a garret gt35/40 for $1500 both dual ball bearing. I think that's the wholesale price for what they get the turbo for and i get all parts wholesale as long as i Promote there new business and put a few large stickers on my car which i dont mind. So if i get a large turbo like that i may drop the comp just a little more with a bigger gasket. I already have low comp pistons but i may ill lower it a little more so i can run 25-26psi safely. I gotta chat with my unk first, hes the expert on what psi to comp to run with my build setup so ill see how it goes.

just wondering what compression you running now?

Stay away from the 71R. If u want to run 20psi, the RS is going to be pushing hot air. GT30R is way to go from here. But realise, 20psi on a GT30 flows alot more then a your RS at 20psi. Its not apples and apples.

Leave the 71R for high capacity twin turbo setups, like it was designed for.

I got told buy a guy today at turbotech that gt28's can take upto 28psi. He also said that it doesnt matter what size turbo you have most ball bearing turbos can take over 25psi.

I thought GT28's could only take upto 20psi Pushing it.

I thought that pushing a turbo harder than its operational capacity will cause to much hot air thus causing lower HP.

Maybe he just meant that physically the turbo can take 28psi. But its best performing operation is at 15psi etc.

you can probably push it to 20psi
but would the gains be worth it???

eg: 10 psi makes 150kw
15 psi makes 200kw 5 psi = 50kw gain
20 psi makes 220kw 5 psi = 20kw gain
so thats an extra 5 psi for only 20kw is it worth it as it will be out of the turbos effiency range. plus its putting stress on the turbo and will lower the life of the turbo too.

Quote:

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Originally Posted by Limbo

just wondering what compression you running now?

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My compression is 9.1

replacing the rings on my car atm and i pulled off the turbo last night and found it had a little bit of shaft play. Not alot but i like to be precautious so i dont have failure in the future. Thats why i sorta brought back this old post.

Its hard finding the right turbo i want now i guess. There are so many different variations of higher boost but lag, lower boost not as much HP but less lag. Some peoples views are different to others because its the way you drive and everyone has different driving styles. Some dont mine a little more lag for the greater HP and some will sacrifice some HP for a nicer more bottom/mid end drive.

I guess im just trying to find a nice way to get 300hp atw's and still have grunt in the lower to mid range so when your in 5th on the freeway you dont need to drop back gears to get in front of that person sitting 10-20ks less than the speed limit in the right lane. I hated my old t04e but that wasnt a ball bearing but still i hated lagg and never wanna go back to it. But when the power came on, in the t04e you would some how forget about the lagg in a flash cos the power was soo solid and strong that nothing else mattered.

Such a hard decision. There are so many talks about this in the forced induction section and the conclusion ive come to is its all about what type of power you want and when you want it.

I just wish i could figure out what i want

Ok guys this is the details i gathered of the turbo, so i finally know what turbo i have now and what i can push it to.

Compressor housing:
Garret A/R60 m24 1-2

Exhaust housing:
Garret 0.64

Badge:
DI 0334J
1441-G1f00
466541-4

The turbo is know as the GT2560R-4 (aka gt28r) which can take upto 330hp and has a max efficiency rating at around 14-16psi depending on the setup. It has a really quick spool and its nice but it just lacks alot in the top end.

http://www.turbobygarrett.com/turbob...R_466541_4.htm

Should i spend $700 on a rebuild which effectively make my turbo brand new. Or do i sell it for say $500-700 second hand and spend an extra 600-700 and get myself a gt28rs or Gt2871r or even a gt30r?

The turbo now i think would have another 50,000k's on it before it needs a good rebuild. It has slight shaft play but nothing to bad.

What do you guys think? rebuild or upgrade?

Put in mind that my car has been tuned at 7psi with around 240hp at the wheels with this turbo over a year and a half ago, I've changed manifold, intercooler piping, Intercooler, fuel pump, Injectors since then. I've never really taken it past 7psi properly and i was going to the other day but i need new rings so im replacing the clutch, LSD, fixing some exhaust leekage and maybe replacing the turbo so i can push this thing to a max of 20psi or more. I've build the engine to run upto 25psi but safe 20psi but ive never even got close.

next jump up GT2871r or go straight to the GT3071r.
The GT3071 also comes with a T28 flange

Quote:

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Originally Posted by Limbo

next jump up GT2871r or go straight to the GT3071r.
The GT3071 also comes with a T28 flange

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I'm looking at either a GT3071r or the below. Atm im going for the gt2871r as its a cleaner daily drive. plus i dont think i wanna go for more than 400hp at the engine and the 2871r is suited for around that power.

Garrett GT2871R

Compressor:
Wheel Diameter: 71mm
Trim: 56
A/R: 0.60

Turbine:
Wheel Diameter: 53.85mm
Trim: 76
A/R: 0.64
Wastegate: (external if possible) if not i will weld the internal gate up.