RB25DET + gt35 or gt30?

[eimarshall]

i just bought my s14 thats running an rb25 and i'm thinking of dropping from the current GT35 with .82 a/r to a GT30 with either a .82 a/r or .63 a/r. i'm looking for a more usable powerband and more streetability. could i just go for a .63 a/r on the GT35? i'm really looking for spool but i'd like to keep it over 400whp. i've heard the the GT35 with the .63 a/r can work but can be prone to surge(right?) and is harder to tune for some reason.(?)

as far as i've reasearched the gt30 just flows about 10-15 lbs/min less and avoids surge. the gt35 has more flow and can be prone to surge with the smaller a/r's. the spool really depends on the turbine a/r but i wasn't sure if the two turbos spool differently with the same a/r.(?)

i know lots of questions in there but i guess i want to know which turbo spools earlier with the same a/r?

any advice for a RB newbie?

thanks.

[FinkenS14]

Theres alreday a thread reight below this

35r vs 30r

Search

[eimarshall]

uuuuuuuhhhhhhh.......where?

all i see is the GT3071r vs the GT3076r thread.

show me a link and i'll believe you fink.

[DrifterProdigy85]

In T3 form, the .63 housing is gonna have too much backpressure with either 30 or 35r. Stick with the .82 housing and choose the turbo that best suits your powerband. Id say if your revving to 7000-7500rpm then go with the 30R. If going over 7500rpm then go for the 35R. Those two turbos are the difference between a torquey/responsive engine and a peakier hp engine.

[eimarshall]

awesome! thanks prodigy!

i'm definitly leaning towards the 30r because its my dd, not my track toy.

is there any difference in the spool characteristics, between the same size a/r on the 30's compared to the 35's?

[DrifterProdigy85]

I dont know exactly but id imagine around 400rpm difference. I dont know how much of it you would notice though. The RB makes alot of tq during spool up so its gonna pull itself to that rpm pretty quickly. What you would notice the most is the response difference. The 35R isnt gonna feel as snappy on boost transition like the 30R would.

[GSDKinked]

zer...-mani

Talked about in there.....

and some other places but I'm too lazy to look.