I've done it, once. Stacked was .004 faster in the 1/4 mile than with just the 178. The power fell off a cliff in the upper rpms. Down low it was a monster. I left the 65 on returning from the track. I'd hit huge boost at part throttle with the air fuel ratio in the 14's. At full throttle it leaned out as well. I'm suggesting that unless you are tuned correctly for it, your engine won't last long stacked. If your willing to get the fueling mods needed and have your car tuned on a dyno, stacked, you will love it. It will throw an over boost code from time to time. I believe it's triggered around 22 psi.

Les