Re: Some Boost Controller Info

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <031301bdf13c$0c9a1c00$01aca8c0@wol155.radstone.co.uk> sevans@radstone.co.uk writes:

> >There's a subtlety that no one at Audi has been able to explain to me -
> >in the earlier MBs, one line goes to unthrottled air, i.e., intercooler
> >output.  On the later ones, it goes to throttled air, i.e., the inlet
> >manifold.

> >Anyone know why this change was made?

> Are you sure about this? On my MB (same as yours) the frequency valve > takes
> its low pressure input from the intake elbow of the turbo and its high > pressure
> input from the back (bulkhead end) of the inlet manifold. I understood > that this
> tapping is from a drilling that runs the full length of the manifold to > the
> turbo side of the throttle. Is this not so?

Yes, it is.  In the context of my comments (requoted above) both of us
have "earlier" MBs.

On the "later" cars (e.g., John Robinson's) the takeoff point used for
the wastegate frequency valve on our cars is covered by a rat-sized
condom.  The wastegate frequency valve input is tee-ed off the ECU
line.

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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