I already have the GMPP Sport Exhaust and I'm looking into getting the header next. Does anybody know what kind of hp I can expect from having the almost complete exhaust system? Just a ball figure, I'm curious. My existing mods are in my vBGarage if anyone needs to know.

p.s. - if I were to get the zzperformance downpipe too, what might I expect?

http://www.zzperformance.com/cobalt_...=540&catid=155

Thanks guys!

 

I'm going to estimate but i imagine a good 10-15+whp with zzp's 1 3/4th header and 3" downpipe on stock boost. More with S2

 

Why not go with the GMPP manifold? You'll get I believe 5hp... but it'll bolt up with no issued what-so-ever.

 

Because you don't buy a manifold if you want performance.