The surge is no big deal if you ease off the throttle and don't just slam the TB shut. My GN was running 24lbs on the street with no blow off.

Now,the Turbo LS1's we build ussually get 2 TIAL 50mm blow off's. 1 after the turbo and 1 after the intercooler.This ussually helps relieve the pressure when the throttle closes -in affect keeps the cold pipes from blowing out of the silicone couplers.

 

i use the HKS SSQV on my truck, doesn't sound as ricey when its coming from a throaty V8. Its loud as hell though when I'm wot and i let off the gas quickly, makes people jump. No springs to mess around with, hook up the vac line and go.