View Full Version : garret turbo ?s

02-01-2003, 04:56 AM
while sifting through that other angry thread i looked over to the cheap turbo site that haxxord is buying from and had a few questions i thought you turbo experts could answer.
what are the differences between the t28 and gt28 with respect max power output, lag, and are they bb or not? (for use on a stock internal sr)
same question with the gt25r .64 ar and the gt25 .86 ar.
i've read all the specs on that site, but since my tubo knowledge is limited it means little to me...
also, will these turbos "bolt on" to a stock exhaust manifold and downpipe?
i currently own an upgraded sr t25. guy i bought from said it was a t25/t3. when i bought it i got a decent price and was convinced that it was barely used. (still am) i never even got exact specs on it. (ar, turbine or compressor wheel size) another thing that bothers me is that abailey said he used to have a t25/t3 and it had a clipped wheel and spooled rather slow because of it. how can i tell if my turbo has a clipped wheel?
was thinking of going with one of these garret turbos now, but am unsure and looking for advice. i want around 320-330whp and the less lag the better.

02-03-2003, 03:17 AM
sorry i even asked....

02-03-2003, 04:43 AM
here is an old e-mail that i have about the gt25/28.
these numbers where given to me by someone in the se-r community very familiar with turbo's

Garrett GT28 (Ball Bearing)
.64 A/R Turbine housing
62 Trim Turbine

.60 A/R
60 Trim

This turbo is just a bit smaller that the GTiR T28 and should be able to support 240 hp.

Garrett GT25 (Ball Bearing)
.64 A/R or .86 A/R
76 Trim

.70 A/R

The .64 A/R can support 325-350 hp and the .86 A/R can support 350-400.

HKS 2540R Ball Bearing)

.64 A/R
76 Trim

.50 A/R
46 Trim

This turbo is $$$$$! It can support 300-325 hp.

02-03-2003, 09:09 AM
My goals are pretty similar to yours and I've achieved them with a GT25 turbo CHRA #446179-0031. Turbine stage is 1.85/2.12 diam, 76 trim, .64 A/R. Compressor is a GT35 wheel with 1.94/2.80 diam, 48 trim, .6 A/R. You should get close to your goals with the usual 3" exhaust, FMIC, ecu and if you add some mild cams (I use 256in, 264ex, 11.5 lift) you should get up around the 350rwhp mark. Setup works quite nicely with minimum lag and while it isn't exactly putting out big hp it should still push you along reasonably well.

If you want to trade off some drivability for cost then you could lose the cams and use CHRA # 446179-0032 (same as above but with compressor trim of 56), use a GT25 with T04S front or move into the HKS GT2540's, GT2835's, new GT-RS (my favourite atm) etc

02-05-2003, 04:44 PM
thanks for the good replies.
IMOA, how does it spool? what rpm for full boost? what's your setup? seems nice.

02-06-2003, 01:20 AM
It will spool a bit slower than stock but maintains drivability, pretty much any gear you'll have 20psi by 3500rpm, more likely around the 3000-3200 range so you've got a good 4000rpm to play with.

In brief the setup is the above turbo, the cams, CES Racing dump, HKS exhaust manifold, FMIC, bigger tb, Z32 maf, daughterboard and custom chip. Apart from that I've done a lot to keep heat out, got oilcooler, bigger sump, radiator for safety, ample fuel and the engine has had a bit of work to make sure it stays solid.

Like I said, it's a street/circuit car so tractability, throttle response etc has taken priority over big power and in many respects it's better than a standard car in that regard