When I instaled the H pipes in my car it ran so better that I had to change the jets in my carb.
Now the car runs better, sounds like more uniform. I noticed a little better fuel milleage, and better performance also. It runs smoother and faster - you can feel it. In the other hand it sounds quieter. But know I can desacelerate the engine without hearing that kinda shot noises.
I'm talking about a street car that revs 5500 not a full racing one, so I'm not sure about it's performance in very high rev engines...
