[urq] Wastegate "Chirp" on Rally, SCCA and IMSA Race Cars

[Stephen Kraus]

Actually, from what I've heard, it was the re-circulation. The Group B car
didn't come equipped with vent or blow off valves, instead when the driver
let off the gas to shift, the extra boost pressure got dumped into the
turbo, which is then pushing air against a closed throttle plate, causing
the turbo chatter you hear.

Its louder because the turbo doesn't have all the plumbing our cars do.

On Fri, Sep 14, 2012 at 7:50 PM, John Koenig <koenigj at comcast.net> wrote:

>
> Since no one else has answered, I'll take a stab at it.  I think the sound
> is an artifact of a wastegate design that vents directly to atmosphere,
> increasing its responsiveness and mitigating delayed effects, rather than
> back into the exhaust.  That said, there are a lot of guys here who are
> much
> more qualified than I to know the facts, and the actual applications, and
> answer accordingly.
>
>
> -----Original Message-----
> From: urq-bounces at audifans.com [mailto:urq-bounces at audifans.com]On
> Behalf Of R Wong
> Sent: Friday, September 14, 2012 6:58 PM
> To: urq at audifans.com
> Subject: [urq] Wastegate "Chirp" on Rally, SCCA and IMSA Race Cars
>
>
> Greetings everyone in quattro land, I am reaching out to the board for some
> information on what wastegate Audi Sport used in order to get that cool
> chirping sound from their cars in the late 80s and early 90s, meaning the
> rally Sport quattro, SCCA 200 quattro, and IMSA 90 quattro.  I did spend a
> bit of time searching but was not successful so this is the reason for
> reaching out to the board for information.  One last thing, does anyone
> have
> a chipped ECU they want to sell to me for my 83 ur q?  If so, e-mail!
> Thank
> you very much everyone.
>
>
> Kind Regards,
>
>
> R Wong
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