Have no before and after performance figures, too much changed, but I gutted the 6" corsa tips. I removed the back plate as some have said, then took it to a fabricator and had him plasma cut the inards out. Then added the butterfly internal flap myself. Heck, I can't even tell the difference soundwise under the platform..

Brad, thanks for the information...I really don't look for any performance gains in this, the boat is just too quiet...Do you feel putting the internal flappers was necessary? I was not going to do that.

Exhaust
 

Gutted corsa tips...

Brad, is that a H2X?

Hammer.