I have an 3.0" Alta that I would like to quiet down by using this Apexi Electronic Valve controler. I will be able to adjust it from inside the car. I want the valve 100% open around town and 30% closed on the freeway. I would love a valve that was vaccuum operated, that way it would open under full boost.
Here is a picture
Mario

 

I know a few of my friends who had something like that on their srt-4 to releave all back pressure for racing, it was on the downpipe and it would just open dump to the ground. but that was for a turbo application. i know 3" is really big for our cars but im not sure closing the valve much more than 50% would be safe as the exhaust wouldnt have much path to escape....ehh, i could be wrong just my .02?

 

I wonder if you could rig that up with some parts off a bypass valve? Basically the same operation that you're looking for.

 

This would not be a dump pipe but would be welded in line between the front resenator and rear muffler. I only want the valve to close 30% when I'm cruising on the freeway and not under boost.
M

 

That would be great because it would be all automatic, I guess it would work similar to a FMU.
M

 

Quite a few cars have kits available for those. Scoobys, Evos, even M3's. They work great. I don't have any personal experiance with any of them, but i'd imagine it'd work on a MINI.

Here's a sound clip of a similar device on an M3

The valve doesn't actually cap your exhaust, even closed all the way. I think it works kinda like a redirect. A capped exhaust wouldn't really hurt anything, the engine would just stall I would think.

 

Yeah I thought you had to have an altranate path for the exhaust to flow if you have one of these things. I thought they were full open or full closed. REF randy webbs prototype exhaust for an example.

 

All the ones i've seen for other cars have been redirects, not cutoffs. I would think you're right about the full open/full closed. Not sure it would make any real difference if it wasn't one or the other. 30% open would still be loud (Bypasses most of the sound muffling ). Is your exhaust that loud Mario? It didn't seem loud in person, is it mainly drone that's bothering you?

 

Some dude in korea installed a replica of the apexi system (It is manually controlled by pulling control wire seen above) He states that he is very satisfied with the device, mainly because of the feature and price..