there's lot's of different things that could have been different on that Z and on that SS. Maybe the SS lowered his tire pressure a little and had better traction. Maybe that Z had lousy compression in a cylinder or two...maybe he was in safety boost, maybe he needed a tune up. what did they both run??? Come up to Dallas...we'll go out to the illegals. I'll line up my 100% stock Z against an SS and show you.