My exhaust is too loud - how to make quieter?

[Jeff Frigo]

Originally Posted by undy

I had the "auger" style mufflers on my ride and picked up 40 rwhp (and a small amount of noise) when I went to the Classic Chambered exhaust. There's just too much exhaust impingement with the spiral style...

What was the hp diff with the chambered? Pleases explain exhaust impingement.

[undy]

Originally Posted by Jeff Frigo

What was the hp diff with the chambered? Pleases explain exhaust impingement.

I gained right at 40 rwhp with the CC pipes. I also added true merge collectors that may have skewed the results a bit too.

As the exuast travels down the muffler it's constantly "bouncing' off the angular augers. Just that fact that the exhaust is repeatedly "hitting" the spiral center section creates undue back pressure, ie; impingement.