Re: Fuel injection questions

[orin@wolfenet.com]

> > Altitude compensation?

> That would require it to have a reference standard - a reservoir of
> gas at sea level atmospheric pressure.  Can't see one.

Weird.  It's beginning to sound like it's not really doing anything.

> > > > BTW, for us US types, what is the spec for HP and max boost for your car?
> >
> > > 200bhp stock.  Maximum boost is something like 7 or 8 psi.  I'll check
> > > and post a note later.
> >
> > Thanks.  What's the compression ratio?  From ScottM's post later, it sounds
> > like your car is very similar to his...

> It's "high".  Sorry, but it's _still_ cold outside.  I'll get the
> metrics in the morning.

For comparison, the early MC is 162 bhp SAE (121 kW DIN).
Compression ratio is 7.8:1, max manifold pressure is 1.42 bar,
or about 6 psi boost.  System pressure
is 5.8 to 6.6 bar.  Warmup regulator is part # 034 133 403 A (and is
actually called a warmup regulator in the Bentley).
The system pressure is the same as Scott reported.

> > As for computers, so far, it seems the MAC12 is a slightly stripped
> > down MAC11 (no O2 sensor input or charcoal canister output) and the
> > MAC14 which Scott has is the dual knock sensor evolution of the
> > MAC11.

> The MAC12 as a degrade of the MAC11?

> Makes a great deal of sense.  Postulate an environment in which emission
> controls were imminent - the WR in Euro form is an emissions joke.  The
> MB might well have been developed to provide a hardware vehicle that -
> in contrast to the earlier (Euro) WR - _could_ be retrofitted with
> emissions controls at short notice.  Audi's objective was _NOT_ to
> improve system and control pressure management, but to provide a
> configuration that supported closed-loop frequency valve management
> as cheaply as possible on the "old" 10V engine.  The other essential
> mechanical steps were increasing compression and dropping boost
> pressure.

I also suspect they wanted a greater commonality of components between
engines.  At the time they developed the MC, US sales were up.

> It didn't happen - and the MB's frequency valve was left open-loop.
> By the time emission controls became mandatory in Europe, Audi had
> switched the ur-quattro to the pulsed injection system used in the 20V.

Makes sense, the MC system was by then well out of date; they essentially
gave up the frequency valve system on the NA cars around 1985 here.

> Why not adopt the US emissions controls?  The standard ur-quattro has
> always been rated at 200 bhp in Euro form - whacking n% out because
> of a catalytic converter is hardly "Vorsprung durch Technik".

I think that the lower hp is mostly due to the junk gas over here.
After all, the MC will 'run' on regular unleaded.  After all, we
bump it over 200hp pretty easily... I see around 185 hp on my g-tech
so I'm well over 200 at the flywheel.

Orin.