the reason the piped speed planes seem the come alive all of a sudden is that on the ground the rpm is to low for the pipe to work as the plane gets airborne the prop unloads and the pipe starts working. ofcourse you need many other things to be set up correctly for this to happen.

David
The pipe comes in when Rpm and the reflected shock waves atart a sucking on opening and over suck drawing fresh charge into the pipe through the exaust then another wave on its way back stuffs the mix back in.
Different waves are involved, gas pressure pulse ,speed of sound pulse,(pulse down the material of pipe?)

That is why the pipe shape,header length and stinger length are all critical--to RPM.

That all I remember at the moment.

oh yea--fuel demand goes way up when on the pipe.

Hope pilot is in pylon when it comes on.
When they miss it can get scary--speed ships are fat even with 1/2 the prop gone!


Tuned pipes are why I never flew speed, its enough work to make this silly stuff work already.

David
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