I narrowed it down to these two based on sound. I live in a nice suburban neighborhood and I can't be waking the neighbor's kids from their afternoon naps with something that sounds like a test CD for a subwoofer.

So...with that in mind, will stillen's dual pipes really make a difference? I'm not thinking so much about the power (6 vs. 12hp gain is going to make no real performance difference), but more in terms of how much more smoothly/freely the engine revs and feels at higher rpms.

Also, some sort of FI system will be going on by the end of the year after the tuners have the software a little more perfected, so that has to be considered also in selecting the exhaust system.

 

Borla

 

Oh yeah....forgot about them. They have a solid reputation for mellow sound and good performance gains. How's the fitment?

 

I think Borla is my next mod. It's weird it is one of the cheapest exausts, with some of the best gains, lighter than stock, AND true duel?

It almost sounds too good to be true to me.

 

That's because exhuasts are all they do, and their manufacturing costs are much lower due to their volume. I also have data from real world testing I have done myself on a Borla equipped car
(not a Z, however) that showed true gains.

 

the stillen reportedly has the best gains of any exhausts out there. there are some dynos on g35drivers.com, just do a search. now whether you like the company or not is a different issue, there are some that just hate them with a passion.....but i say it's in the numbers. both sound real good though, and not all that loud. from what i heard, the borla construction doesn't compare to the stillens. hope that helps!

n1cK!