Originally Posted by Two Plugs
You will never gain extra power by just replacing the exhaust muffler. Only the sound counts. But I'm sure the V4 makes an excellent concerto... ;)
If the purpose is getting extra Bhp, you have to mod the entire exhaust system from cylinder to muffler, add a powercommander, open airfilter, etc.
My experience with before and after dyno runs (same day) tells me differently. I gained 6hp using slip-on to my VFR800 and 5 more when I went to a full system. Similar experiences with other bikes.
Agree though that uncorking the whole system gives the best results. :)