Originally Posted by DannyGT

The fact is this guys, no one has come close to their claims (Stillen's)...period. Those that have, had more mods done and STILL fell short of the advertised claims. Maybe someone messed with the dyno, who knows. Let’s not even bring up RCZ’s car…Custom tuned by a super aggressive tuner amongst other things.

Anyway - those that have the GTM kit are running flawlessly. Shumby, with his fine example of already achieving the numbers of the low power numbered Stillen kits out there with ONLY 6psi, has the most important thing of all, drivability.

That’s what sets apart real tuners....They can [try to] make more HP than the GTM kit but so far the drivability aspect of their tunes is a ******* joke. When you look at both tuners its clear both pushed the kits to the limit, and no one will get those numbers. I sure don’t expect to get 460whp. GTM has a few dyno sheets showing power ranging from 420-460. But their advertised hp claim shows they except, with a safe tune, to be in the 410-430 range. I do know for a fact that I will be in the 410-430whp range, and even more so with water injection/custom tune. My goal even before I bought the SC was strictly to hit 420whp. I know I can hit this with no fancy tune.

I’ll tell you, it’s been a great experience doing this install, and I have to say that GTM is 95% perfect with their instructions. I will be making edit’s to the document so that anyone else tackling this, being it pro or not, can have that much more specificity.