The original PSE

[The Radium King]

you could probably use the same mechanism and control signal as used by the resonance flapper on the intake to control a cutout on the exhaust - over 4000 rpm the cutout opens and bypasses the muffler. you would need to confirm that it could take the heat, need one on each side, and mebbe get a bigger vacuum tank to address the larger load.

[JFP in PA]

Originally Posted by The Radium King

you could probably use the same mechanism and control signal as used by the resonance flapper on the intake to control a cutout on the exhaust - over 4000 rpm the cutout opens and bypasses the muffler. you would need to confirm that it could take the heat, need one on each side, and mebbe get a bigger vacuum tank to address the larger load.

Got to be careful about how you rig this up, several European countries have noise limits (in dB) at certain speed levels (KPH or MPH) that the system has to comply with to pass their version of inspection. To my knowledge, Switzerland is the worst in this department, and that was the benchmark the PSE with all the electronics and vacuum hook ups was designed to pass.