a 3" exhaust and said that was limiting him. my exhuast is 3.5" so i should be ok there.stock heads/cams/valves will be re-worked next summer. gonna go the full tomei route(solid lifters, cams, ferrea valves, etc.) the guy i bought it from said he spooled 9psi @ 4k in 4th gear. and 25psi by 4.5k!! sweet... heres his email. he has pretty much the same philosophy as me
=========================================================
Joel,
For example, in 4th gear on my car this turbo made about 9 PSI by 4K
RPM, and 25 or so by 4.5K. The boost curve goes almost vertical at just
above 4K. The inline-6 configuration of the Supra motor is an ideal
setup for getting hot exhaust gases to the turbine to spool it, so I'm
not sure if other engine configurations would spool as well or not. On a related matter... Some people would think that spooling after 4K
RPM would feel "laggy." IMO the turbo does not feel laggy. True, it
does not make boost at 2500 RPM, but that doesn't matter as I never race
at 2500 RPM or try to make a car accelerate hard at 2500 RPM. I have a
V8 in one of my other cars and even that car doesn't start pulling hard
until about 4K RPM. IMO, lag is FAR over-emphasized. So long as you
have RPM headroom so you can work in the high power range without
falling out of the power band when you shift gears, you're better off
(maximum acceleration wise) with a motor that makes power in the upper
RPM range as it allows you to make more use of the transmission's
gearing by staying in each gear until you reach a higher speed. This
turbo, on the Supra, really needs a bit of RPM increase to make the most
use of its power capability -- the stock Supra's 6800 RPM rev limiter is
a little bit low. I have my rev limiter turned to 8200 and it is
perfectly matched. I'd say anything in the 7600 RPM range would be okay
as well on the Supra, as I often only spin to about 7500. The Z might
not need to be spun quite as high -- I just don't know. -Steve
=========================================================
 |
