Can anyone verify Stillen claims of +18hp?
 

They claim 18hp for the exhaust, and another 16 for the high flow cats. That adds up to +12% at the rear wheel.

Has anyone done either or both and verified the claims with a dyno. I would spend the cash for garunteed results, but I don't believe the claims without an independant verification (I am a scientist after all).

search, your not going to see gains like that every time. Most of there testing is done on stock cars with that being the first mod...

But plenty of people have done independent dynos showing great results..

theres prob 10-15 threads on this already

my car put down over 330 whp after tune with my mods in my sig... most of them being stillen.. The dyno is known to read high but I was told a full bolt on hr Z did 297 the day before soooo who knows. Fitment of the exhaust will give you some headaches though.. But after some tweaking people get it to work.