Arrow slip on, amazing!

[Brookland27_imp]

Stock pipe usually not replaced for the power..it's for the noise

That not entirely true. I've gained probably 8-10 hp with a full system pc5 etc. For something as simple as unbolting an exhaust and rebolting a new one that's pretty drastic. I. Fact there's little else you can do without cam work to get more power. Arrow makes race exhausts and they make power i have their 4-2-1 header and im very happy with it. For just a slip on 4 hp at 6500 rpm is not bad espessially considering it looks and sounds better than the stock unit. Other more free flowing slip ons have been reported to give gains in the range of 6hp at 7500 rpm which is outstanding. To me the 3500 rpm scenario is a moot point. That's cruising rpm if you want power from an in line 4 your going to have to Rev it. IMHO of course