exhaust valves?
 

Literally, a valve in the exhaust. Doesn't appear to restrict flow much when open, and can create more backpressure when close (good for lower end tq?).

I know several BMWs and other cars have an active valve in their exhaust. I was wondering how effective these were, and has anyone though about getting this to work with a tune? o.O Would be pretty cool to go into "ninja-mode" whenever you want.

Well you technically cannot run the same tune with a valve in the exhaust or even a silencer for that matter. They cause so much backpressure that you get detonation running the same open tune when resteicted.

Now if you had an automatic valve that is in quiet mode under low load and opens up during wide open throttle or a different boost level you would be able to maximize the tuning in one map.

Thanks,
Phil Grabow

Yeah, that's basically what I was thinking. However, no way to have stock ecu support am output for an auto valve.

Ninja mode - I meant when in parking garage or quiet neighborhood at night while driving slow. Shouldn't affect an open tune, would it? Else just load different maps onto ecutek?

They make exhaust valves with an actuator built in. From what I remember they basically use a wastegate actuator so as you increase boost it automatically opens up.

Now if you're NA it could be reversed so at high vacuum it's closed. The electronic valves are too slow to use a TPS input however unless they've come out with some high speed versions.

I wonder if this is even worth tuning for... and if there's any tuner that would be willing to experiment with this...

In any case, if it'll silence the exhaust at low speeds, I might get one. Just hope the thickness won't be an issue.

Google a varex muffler

Seen something like that before, but I am looking for a solution that'll work w/ my planned exhaust system. I just need a solution that'll make the exhaust quiet for those nights when I have to drop someone off late at night... :thumbsup: the tuning aspects are all just random interest.

I have had a similar idea in the back of my head for a while. I had been thinking along the lines of using one of the custom maps in ecutek to control it and maybe even linking it to the VSC system. ie quieter with all the nannies on and louder when its all off, with sport somewhere between. But that may make the tuning tougher.

Literally buy a perrin catback exhaust and whatever headers. It will be literally stock when puttering around town and wake up once you get in it. My mom / grandma / sister etc couldn't tell the difference between the catback and stock or between catback and the header. Or even cheaper just get headers with stock all else. Valve would be expensive and time consuming

That would defeat the purpose... want best of both worlds, need/want a solution.

I thought the purpose you desired was something that was quiet normally but then woke up when you felt like it, otherwise it'll be fairly expensive. I dont expect this to be a sub-$1K system

Valve is like $100. Only used when slow driving in parking structure or quiet residential area. No need to tune for it, the tune was just a thought.

There was a guy who did this custom exit exhaust with the help of @FT-86 SpeedFactory, but the thread escapes me

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