I just purchased the HKS exhust for my 01 GS 430. I heard it had a nice sound, I have to put it on. They said 5 HP gains... I am wondering if anyone has put on a FULL exhust system and does it make a signifigant difference?
I called up Swift (SRT), got the intake and asked them... They said they only recommend the Greddy cat back system (no longer available) for their $30k twin turbo upgrades, otherwise it is not worth it. Does anyone care to dispute that?
Anyone ever see an aftermarket y-pipe and manifold back piping sold for this car? If so by whom please...
-rob