Hi there, everyone I speak to says the same thing. Here is what I feel that happens. AfterI had Aluminum flywheel put in , I had it dynoed and it was less than what I had before. Now when I'm the 1/4 mile I notice I can't get into the 11 second mark. When I was doing it before.Now when I'm on a road coarse, I feel that I could pass someone on turns , but not aloud too. I know all vipers are pretty much the same,to a point. On a straight away it seems like the car makes alot of accelleration noise but isn't going as fast , and can see the person moving just alittle faster. I know I need alittle more HP ( who dosen't ). I just feel something isn't qiute right. I have headers , cats, DC computer upgraded.