Variable Tuned Pipe.....


Dec 26, 2007
Scottsville, VA

Stumbled across this site showing a variable displacement (for lack of a better description) tuned pipe....maybe this is the next step in tuned pipes?....Interesting theory that seems like it should work but I'd be a little concerned if the inner workings get gummed up by carbon or caked on oily residue over time.

This site also have a very good animation of how a tuned pipe works.

The address is:




LORD VADER Moderator
Jan 16, 2008
pampa texas
I have looked at the site that cool! Go karts that run tuned pipes had what they called slipper pipes, they have been outlawed at most tracks from what I've read. The slipper pipes work and if it gets sticky, its cleaning time if you want to mess with them.
Andy I see nothing wrong with one of these pipes as long as you keep them quiet in the public as most people don't like noisy things and we got to keep up our image. Law abiding citizens that we are?!
Those type of pipes you have on the link might not be that loud my black bike's pipe is modeled on that pipes design, I don't have the slipper stuff inside but have the out side can and one stinger pointing at the ground for less noise. That is the first time I've seen a spring loaded pipe interesting and neat.
Good find.
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New Member
Feb 26, 2008
Your the man Terry, first the split tank, now this. Does it improve the performance alot? I'm sure it is louder!!! Thats wild, got me thinking.....

I dont know yet Geo if it does or not. Just dreamed it up sitting in the garage (remembering when my baffle fell out) and the little bit it changed the bike. On this one I havent noticed much but i really havent had time to mess with it much after I did it. My son said that it was messing with the local gearhead dude. Said he drove by with it wide open and he was watching him go by then he went around the block and closed it off and came back and the guy was shaking his head. gotta laugh.
I think this has promise but I think that Im going to have to rebuild the inside maybe make it look like the SR 71