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Re: Chirping TURBOS-- ANALYSIS
>REWORDED QUESTION: Why do world rally cars and other turbo race cars, and
>the S1 Quattro and the vintage IMSA/Transam turbo Audis CHIRP like crazy
>almost all street turbo setups don't CHIRP at all???? This question has
>driven me nuts so i resolved to get an answer.
In your list of answers, I didn't see the following explanation included.
CHIRP, CHIRP sound is not the sound of the wastegate opening, it is not the
whooosh sound of a bypass valve and it is not the buuuuurp or phffffffft
of a dump valve. The CHIRP, CHIRP is produced when the throttle plate is
and is the sound of the boosted air pressure wave in the intake plumbing
off the thottle plate and reversing direction and then reflecting off the
compressor blades and reversing direction, and repeating this cycle. This
can be heard in the trans am and imsa gto cars and also the group b rally
The only audi street car which I have ever heard make this sound is an 85
with the 20V engine installed which lives in Colorado. This car is using a
hybrid turbo and running 30psi of boost, sometimes more. It's an
cool sound but, it is not a sound you want to hear if you desire more than
mile distances between turbo rebuilds.