I just bought a set of long tube headers and installed them this past weekend on my 99 z28 making it a full bolt on car. My friend has a 99 z28 also with just a lid and LM exhaust, both cars 6 speed. We ran them on the highway and i only beat him by like 1/4 car length from a 50 kick up to about 120mph. WTF? does my car need dyno tunning after a header install or do headers just not make much of a difference???

 

what is the weigth difference?

a full tank of gas, full option and a heavier driver could easily make the difference

as could the way one of you was shifting...shifting early or not fast enough

as the saying goes...anything can happen on the street

 

Thats true, anything can happen. I guess it could be a mix of things. My car has had the same tank of gas in it for the past 6 months cause i just brought it out of winter storage. He's been driving his this whole time or i could just have my shift light set to early, i dont know. I just thought i would pull him harder than that, at least a car length. we are both about the same in the driving skill department.