I just purchased a HPP3 and ran it on my 99 Z28. I could "feel" and improvment to say the least. I have not run it at the track yet. However it did seem to make me faster. I always see people bashing Hypertech. Is there some reason?? I realize there is probably better (more expensive) stuff out there but...come on!

 

I used to have a HPP for my Z and then I started to add parts like a new manifold, deleted the egr and installed injectors and all those goodies and sold the HPP cause I needed something more than what HPP could do.

HPP IMO is good if you don't have very many mods. Just my .02 cents worth