Open Exhaust

[ONE LOVE]

I unbolted the exhaust on my bandit and WOW, I really liked how it sounded. My question is: if I leave the muffler off and just run the straight pipe, is the lack of back-pressure bad for my engine???

[Juice]

Bolt it back on ASAP before you f...k up the exhaust vales. When you let off the throttle, the sudden lack of hot gases being pushed out can cause cold air to be sucked in, which can damage your exhaust valves.

[Rocky]

Problems I see


If all you did is unbolt it and the remaining pipe is too short there is a potential to introduce cold air when you rap it up. Causing a sucked, bent, broken, or cracked valve.

By losing back pressure you COULD loose torque, and COULD gain high end HP. But most likely the first.

[CajunRider]

A neat trick...

Make a custom pipe... baffle or no baffle... whatever way you want...

BUT....

Put a reduced size opening at the front end.... (Like, if you have a 2 inch pipe now... reduce to like 3/4 inch right at the front).

This puts a tad bit of back pressure to where you won't get that damage discussed earlier.

The exhaust I had on my BMW just had a washer welded in the pipe at the front to produce this restriction. It worked fine and sounded NICE!!! (Plus... I didn't loose any torque on the low end.)

[thedrizel]

if all you did was unbolt the "muffler" but left the headers on you won't hurt anything except everyone's ears. If you removed the entire system and ran the bike more than a few seconds, you WILL burn valves.

[dannyt]

Put a D&D can on it. Problem solved.

[wjcook]

I knocked a hole in stock muffler. Big improvement power and sound