3 ms·
That's a cool analogy! I wonder if the exhaust could by dynamic i.e change length depending on the RPMs
by alfiedotwtf 3y ago
That's a cool analogy!
I wonder if the exhaust could by dynamic i.e change length depending on the RPMs
- teeray 3y agoMany antennas do this (screwdriver antennas come to mind), so I’d expect some similar ability to do this with exhaust. The only issue I can think of is turbulence from the seams of segments that extend.
- jacquesm 3y agoThe answer is: yes. The results: 6% gain or thereabouts with a fairly impressive amount of extra complexity. But it can be done. https://www.researchgate.net/publication/322390752_Continuously_Varying_Exhaust_Pipe_Length_and_Diameter_to_Improve_the_Performance_of_a_Naturally_Aspirated_SI_Engine https://www.researchgate.net/publication/322390752_Continuou...
- function_seven 3y agoWay back when Jet Skis had 2-stroke engines, you could buy an aftermarket exhaust pipe with water injection in a couple key spots. This allowed the pipe to be dynamically tuned to different RPMs by changing the speed of sound within the pipe. The stock pipe was tuned to a specific RPM, allowing the reflected exhaust pulse to return to the cylinder just as the port was closing and “slam the door” on the fresh air/fuel charge. With variable water injection, you could have more than one optimal RPM. (All this is from memory as I read the ads in Splash magazine.)
- jacquesm 3y agoOh that's so clever, to use the water that is there anyway as a means of affecting the dynamics of the pipe. Whoever came up with that was on another level.