Has anyone ever tried a slide exhaust system with an expansion chamber... My thoughts on this would be that when it was extended it give me nice low end and as I come up in speed I could shorten it and get the top end I wanted
Slide in exhaust pipe
- Thread starter Shouldbeachevy
- Start date
Aircraft engineer's and hot-rodder's have been experimenting with the concept for decades. Risingsunn and I fooled around with the idea while building a new exhaust for his mark2. We found just the opposite was true... The longer the pipe in front of the expansion chamber the more top end power was created and the more low end power was lost. I solved the leakage problem. The problem I couldn't solve is "space", as in not enough of it to allow a long enough internal pipe room to slide in and out of the "J pipe" to make any appreciable difference in performance...
However it was a good way to gage how long I wanted my exhaust pipe. The day after we finished the mark2 pipe I shortened the pipe on my rattletrap by 6 1/2 inches in front of the chamber. I gained significant low end power and didn't sacrifice any top end power. I then reworked the curve as the pipe exits the header. I actually added 4 new twists to the "j pipe" before it enters the expansion chamber and gained even more low end torque without sacrificing any top end power.
However it was a good way to gage how long I wanted my exhaust pipe. The day after we finished the mark2 pipe I shortened the pipe on my rattletrap by 6 1/2 inches in front of the chamber. I gained significant low end power and didn't sacrifice any top end power. I then reworked the curve as the pipe exits the header. I actually added 4 new twists to the "j pipe" before it enters the expansion chamber and gained even more low end torque without sacrificing any top end power.
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There were a few people running what at the time was called a "Slippy Pipe" back
when I was racing karts, you could get bottom, mid and top end out of the pipe. It just seemed strange to me. Heres some links.....
http://www.muller.net/mullermachine/docs/slippy1.html
http://www.tsracing.com/Techtips/TSslippy.html
2 stroke race boat with slippy pipe http://www.youtube.com/watch?v=hOYvFgGqjUg&feature=related
when I was racing karts, you could get bottom, mid and top end out of the pipe. It just seemed strange to me. Heres some links.....
http://www.muller.net/mullermachine/docs/slippy1.html
http://www.tsracing.com/Techtips/TSslippy.html
2 stroke race boat with slippy pipe http://www.youtube.com/watch?v=hOYvFgGqjUg&feature=related
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my thought was to extend the header but I t looks like they are just moving the rear cone inside the pipe (no leakage) in the video of the boat it looks like there only sliding the pipes around 6"... gonna have to get some mig wire and put one of these together.. cant wait for next weekend
A key to using one effectively is prolly using a tach and learning what rpm to slide it and how fast it should move. Im sure it would be a fun project! keep us informed.
My guess (and that's all it is) would be just use any config you would run as a normal pipe and just add a sliding header pipe setup and use the header length you would want for bottom end and make it slide shorter for top end?
Hard to make room for the entire pipe to slide. Like I said, impractical.
The designers of race two stroke engines finally used variable port timing via various ''power valve'' mechanisms to get the best of both worlds. Nobody I'm aware of ever used a sliding pipe to good effect.
The designers of race two stroke engines finally used variable port timing via various ''power valve'' mechanisms to get the best of both worlds. Nobody I'm aware of ever used a sliding pipe to good effect.
