I think this is what people were referring to them as, exhaust cutouts?

I was wondering if this were possible for a rotary motor, or would it have to be completely custom?

I believe it usually has to do with a turbo setup opening up to straight exhaust when actuated, or at a certain RPM etc.

 

i dont know, i havent seen anything about them. maybe cutout gaskets. or the bends you can buy and cut them and weld them together.

 

it's simply a Y-pipe in your exhaust. 1 route goes to your muffler, the other goes to the atmosphere

i beleive you can either reach under the car to switch it over, or some can be electronically actuated to operate from a control inside the car. summit has them i beleive..

 

Problem with them is, if you have your car tuned with the normal exhaust on, then when you open the cutout, your car is now running lean since you just opened up the exhaust more. Now it's not tuned right anymore.

Same thing if you tune it for the cutout. Then when you run it with the cutout closed you're running rich since you have a more restrictive exhaust now.

 

thast i very good point.

you can get them from ~$25 from summit i think. you have to go under the car to get it though. however, theres a buick regal site somewhere that sells electronic doors that can open from a flip of the switch inside the car. only thing, its ~$100, and its just a bolt on to the piece from summit, or ones like it. i was looking at them a while back, and it seems to be a quality peice.

 

With a properly set up EFI motor though, you could set up some kind of air/fuel regulator to control it from inside the car, couldn't you?

 

you could set up 2 fuel maps..closed loop and open loop. switch between them when you switch cutout on/off..and tune for both on a dyno.

 

Well that does seem like a lot of work, can I use something like an s-afc (i think that's how it's spelt) to switch between the fuel maps? what would I use?