Home Forums TaG Rotax Max RAVE valve – Exhaust Sound? Reply To: RAVE valve – Exhaust Sound?

Eric Alexander

I wanted to bump this back up and add to my findings..

First, once the RAVE valve fully opens the exhaust note does become more aggressive – more edgy sounding.  This sound can vary in volume based on the engines’s state of maintinance: exhaust matting, gaskets, etc.  But the note takes on a slightly harsher or shrill sound once the valve opens.

But here’s a few more questions for the experts:

1. Does the valve snap open when the pressure overcomes the spring rate?  Or is it a gradual opening over a few 100/1000 rpms?

2. Does the Rotax ignition programing actually change the timing at  <7500 rpm to allow the firing of the cylinder to occur as the piston draws even with the closed exhuast valve (on the down stroke)?