more hp...on smaller exhaust?

[Nick M]

On our N/a's the 3 inch makes the power band kick in much higher than with a smaller exhaust.
At least in my experience. I wouldn't really feel any pull until about 4k with a 3" compared to stock.

That is because anything bigger than about 2.5 on a 180 CID motor will lose its scavenging effect. That is what Jeff Lange was talking about. You felt the torque loss.

 

[Poodles]

like I said, depends on the supercharger. A positive displacement supercharger (usually a roots style or derivitive) will be cramming air in, and NOT relying on vacuum to get air and fuel into the engine.

A centrifigal runs as an N/A pretty much until it spools up...

This is all about volumetric efficency and gets very complicated, but forced induction will ALWAYS need a larger exhaust to evacuate the exhaust (nitrous, supercharger, turbo)