I was searching the web and found some type of butterfly valve fitted into a flange which silences the exhaust by changing the valve angle and restricting the air flow. I think you mount this thing between the cats and the catback piping and you may control the valve with an electronic controller. Has anyone seen this thing in person or has more information??? I think it would be interesting for the people who have exhausts but may want to preserve some of the stockish benefits when they are not to enthusiastic, haha.

Here is the link:
http://www.prostreetonline.com/x/ape...trol-valve.asp

Thanks.

 

interesting.

 

I'd run something like this to divert the exhaust to a different exhaust, but I don't think I'm hip on just using the valve to decrease flow to the same exhaust.
These are popular for people who want to divert around the exhaust pipe and go from OEM exhaust to straight pipes with the flick of a switch.
Installing this valve between the cats and the rest of the exhaust is only going to decrease flow and restrict the engine from breathing.
Not a very good idea.

 

The idea is to restrict flow at certain amount, just to silence the sound a little bit when you are cruising around with your new high flow exhaust. When you want to hear a more sporty sound then you open up the valve completely. The thing would be to close it enough on an aftermarket exhaust to have a less loud sound when you are not sporting but not to the degree to strangle the engine.

 

I get the concept, but it's not a good approach for what you are trying to accomplish.

When I pulled the stock exhaust and installed my FI Cat-Back, the car went from 20 mpg to 12. The ECU needed approx 100 miles to adapt to the new exhaust and then my MPG went back up to where it was.
Switching this thing back and forth as you want will cause the ECU to constantly adapt to these changes.

 

I have one for a 3 inch exhaust, only the one I have needs to be welded into the exhaust piping... These things have been around for years, and they work fine.

Your link is to the controller, not the ecv btw...

 

How did you get the cable inside the cabin???