Small turbo limits?
My car is #3200, stock LS1, th400 w/tb, 3.50 gear, 30in. tire, an unknown turbo (maybe an ITS GT66) and its Air to Air intercooled. I ran a 10.78 @ 125mph with a 1.52 60ft. on 7 psi. Only 20deg. of timing and left at 3300rpm. The car only made 25mph from 1/8 to 1/4. I think that it should make more speed on the top end. Could I have reached the limit on the turbo? From 11.80 on down to the tens the car ran 125mph every time. The 60ft times got better and the et's improved but, no mph gain. I'm new to owning a turbo car but, don't these cars run the finish line really good? The turbo is small to begin with, I know. If I changed the .81 a/r housing to a .96 will it run better? Seems like from 3/4 throttle to 100% there is no change in power. The tune is pretty good, 11.5-12.0 afr, about 1450 egt, I'm using bigstuff3 and an exile boost controller. The car was built for a small cube motor "5.3" but, for now it has the LS1 because I had it to use. It runs the first half really good for having a 3.50 gear in my opinion but, its not pulling like I expected. Any ideas?