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Re: mystery valve=decel valve

In a message dated 96-01-06 19:12:38 EST, you write:

> think emissions control has something to do with all this, too.  Don't
>recall all the details, but carb'd cars in the early era of emission
>controls used dashpots (little oil-filled thingies) to keep throttles from
>snapping shut--caused some kind of emission spike that wouldn't pass EPA or
>whoever.  That popping/backfire noise in the exhaust would tell me there is
>unburned fuel leaving the cylinder--also can't be great for the fuel mileage
>(oh..that's right--we're talking Performance here)

Emmissions has EVERY reason to do with it as far as audi is concerned....   A
rich spike for a few throttle close cycles has the chance of washing the cat
with fuel, the return to proper operation, or more specifically improper
operation (like a lean baseline fuel mix or and/or slow O2) can cause a fire
hazard in a big way......   The operational valve will also allow a little
better stalling of the compressor wheel on snap shut throttle cuz you don't
have the vaccuum/pressure relationship you do without it.....  Could help
those end caps stay on the IC too......