I have a pte plenum. I can only run 15# boost without any knock. The car likes to stall when i let out of the gas too quickly. I installed the powerplate today and what a difference it made. The car did'nt stall once-even when I tried. The idle smoothed out and the throttle response was improved. I am now running 16.5-17lbs of boost with no knock on 93 octane. Well worth $59 bucks.