Electronic Exhaust Flap Actuator Ideas

[dark_knight]

So, will keep this short and sweet.
I'm looking for electronically controlled (not vacuum or pressure controlled) exhaust flap actuator ideas. Lots of Europeans use them on their performance package platforms. Anything 2.5-inch and up will be grand.
The plan is to control it with the engine management for different tune settings or even as a screamer for select engine speeds.
Should be fun..

Any suggestions..?

 

[SKINY]

The ST215 Caldina has this, at 4000 rpm the ecu opens the 2nd tailpipe in the twin pipe backbox
A mate done similar with his G7 celica turbo project, controlled by ECU

 

[dark_knight]

Hmmm, let me see if I can find more detail on this.
I was looking for some newer tech though as looking for these bits from the oldies may be a tad difficult.
Thanks though @SKINY

 

[SKINY]

You can buy the valves brand new from Ebay, that's where Mate got his, all different sizes and flange options too

When I say the Mates is ECU controlled it's a ECU Master black edition ECU he has had fitted