ORIGINAL: Jgwright
All I can say is that it works, use a digital fishing scale to measure the static thrust with a 'normal' parallel sided pipe, fit a divergent type pipe of the right size and you should be able to prove to yourself that you are gaining about 5% thrust.
I did the intial tests and then asked Tom Wilkinson to replicate them independently and publish the results.
John
I can verify that they do work....and well!
Being the "doubting Thomas" type, and having to double check things before they are printed, I did a thrust (and loss) test with my MW 54 Mk 2.5 (a Mk II with a Mk III compressor and bell mouth) a few years ago.
My platted front porch is at 6000' msl. My "14.5 lb engine give exactly 10 lbs (several tests, calibrated thrust rig). Add the Wright Pipe (aka: Augmentor pipe) and we now get 10.5 lbs of thrust, and I was not able to get a zero friction set up...so posibbly a 6-7% gain, not just the 5 % claimed, and measured).
Soooo......we see a 30% loss for altiitude and a 5+% gain from the tail pipe. YEH! on the gain....boo on the altitude loss!
Greg