Originally Posted by RayJ
I have always wondered if these coatings effect the performance of the pipe. These coatings are to some degree effecting the sound waves that travel through the pipe as well as the inner temperature of the pipe. All of these factors if I'm correct will effect performance.
Originally Posted by
DS Motorsport
The resonance will be increased because of the harder surface area.
The soundwaves will be absorbed less by the pipe which makes for better performance.
As an engine builder for over 40 years I can tell you both you hit the nail
right on the head. Hard coated exspansion chambers on 2 cycle engines
always make more horsepower & make it easier to control where you want
that power in the RPM band.