What have you gained going to a larger A/R housing?
11-08-2007, 12:31 PM
#1
What have you gained going to a larger A/R housing? I'm looking for any kind of results that others have gained in going to larger turbine housings. I haven't measured my back pressure recently but I'm not gaining at the track going from 18-20psi and the wastegate is still opening. Seems like the top end is falling off as well. I'm currently running a .81 A/R housing but I'm pretty sure back pressure is way up. I tried the .96 a/r before but I didn't have my combo sorted out like I do now. Previously I only saw a 3 psi drop in BP from .81 to .96 but I've reduced my BP issues which were being caused post turbo. My car has been limited to 133-134mph on it's best passes. It seems like most people are able to squeek low 140's out of a 76GTS even on a heavy car so I'm thinking I should be able to run in the 137+ range. Engineermike seems to be doing good with is 3750lbs 383 t76 setup.
11-08-2007, 03:54 PM
#2
I have no insight to your actual question, but for what it's worth I've gone 136mph on a .81AR turbine housing on a TC76 rear mount. I've thought about trying a .96 as well but I'm a 6 spd. With you being an auto I wouldn't hesitate to go up to the .96... your spool up change would probably be negligible.
BTW, my raceweight is around 4000lbs.
BTW, my raceweight is around 4000lbs.