[svxistentialist]

That sounds [zonks!] like a good plan Steve.

I was thinking of a similar idea, different source.

I've known that Ferrari cars have these muffler flaps that actuate to relieve restriction at high RPM. It is interesting that Aston Martin has the same thing, though they refine the idea with the straight through burble at tick-over, which is not measured for regs. Cleverrrr..

Twin turbo Legacies have these actuated bypass flaps for the opposite reason. On tickover they close, because they cut down the normal wide open unrestricted turbo exhaust passage to provide some back pressure that allows the engine to tick over in a less "lumpy" fashion than it would otherwise.

A lot of Legacy owners discard them, they don't like the idea of having an even tickover.

As they are designed for a similar system to ours, they would or should be an easy fit or mod.

I'm not sure if Phil intends to use it to relieve pressure at high revs, or just to make noise. I'm inclined to agree with Tom, the SVX sounds crap when you alter the standard flow. Letting off pressure though at high revs would be positive, however bad it sounded.

The Legacy bypass could work, though it would need to be rewired to open rather than shut. Tomato. Tomato.

Too much bother I'm thinking for an engine whose revs are limited by what suits an automatic gearbox.

Joe