Garrett Gt25bb Vs. Garrett Gt28/71r

[DLRIUZ]

Hey i currently own a R32 GTST RB20DET, mods as follows:

powerfc

sard fpr

fuel pump

700cc injectors

greddy cam gears

Garrett GT25BB

hybrid FMIC

Z32 AFM

HD clutch

3.5 exhaust turbo back

hi-flow cat

AVC-R running 16psi

custom high mount manifold

im about to get a tune and im searching for about 230rwkw but i dont want to sacrifice too much response. the GT25BB currently comes onto full boost around 4000-4500rpm. the car recently made 200rwkw on 15psi without the cam gears, hi flow cat, injectors and fpr.

i was considering changing the turbo to a Garrett GT28/71R before the tune. just wondering if anyone has used this turbo and tell the pros and cons about it in comparison to the GT25BB. tell me what power you made and when it came onto boost. thanks. iam wanting full boost by about 3500rpm.

all help welcome but if your going to just bitch and spam leave your comments to yourself.

Cheers

Brodie

[rb26s13]

wat spec is the current GT25bb

[discopotato03]

All "GT25BB" equates to is GT25 turbine and ball bearing centre section . If it gets full boost at 4-4500 rpm its not very good IMO . I suspect its a GT2540R/GT2876R with either an archaic TO4S compressor or the 76mm GT compressor . Both are a woeful combination .

Same deal , pics and numbers off its ID tag and we can at least tell you what you have . Until its identified its impossible to know which way to go .

Cheers A .

Edited January 20, 2007 by discopotato03

[Dale FZ1]

Read this thread:

http://www.skylinesaustralia.com/forums/in...=127600&hl=

Your search function would have found it.

CHRA is 446179-5031, 48T GT2871R. Early boost, fairly quick response and highly satisfying.

[GTRNUR]

Hi Just came across your thread while looking for suff on GTR cam compatability with Rb25det heads... They work in RB20's and aparently make more low end torque and improve response.. still looking for RB25 data tho.

Anway, I run the same turbo on my RB20DET in my gts4. GT25BB400 with a 0.64 turbine, 0.7 compressor, turbosmart 38mm external gate, 600x300x75 fmic, GTR 440cc injectors, 20lb boost, wolf 4plus ecu, msd dis4 ignition and 3 coil waste spark ignition, 044 pump and a few other things.

I get positive manifold pressure from just above 3000 rpm, 10-12lb by 4000 rpm depending on load and gear, and full boost by 4500ish. I say 4500ish in that at that rpm with full boost within a second or 2 your at redline already so its really hard to say at what RPM it came on at.

The turbo doesn't really start to sing till rpms are above 4000 though. Probably far from being a good match for a RB20, but I use antilag as well, and when its in its effiency range it just goes and goes. If you weren't afraid to rev to 8000 it would hapily go that far. I shift at 7500.