Originally Posted by jyupitt1

My dealer GM was not surprised at all that aftermarket headers lost power. SDG after a few days of driving with catless, i can say that now i am used to the sound and can possibly take more . Drive my car and see what you think. I think the sound level settled down or i'm just used to the sound.

Originally Posted by sdg1871

The minute I saw those Dyno results those aftermarket headers came off immediately. This is not to say that those aftermarket headers wouldn't gain the car power in a different configuration with a different tune. But with my configuration and tune they were a power suck.

I wonder if the GMG headers gain power. GMG has a great reputation in Porsche racing and I just can't imagine they would put a product out that didn't make the car faster. That is so not them. And who knows maybe Champion Motorsports one day might develop a set of headers that would make more power with its mods and the GiAC tune.

Originally Posted by PMNewton

I have a set of Kline's headers on the way. They are equal length which is definitely an advantage over the FVD. I haven't seen any documented power gains though. Purely speculation.

- Patrick