Fuel injection questions

[Phil Payne <Phil@sievers.com>]

In message <199704202205.PAA17251@gonzo.wolfenet.com> orin@WOLFENET.com writes:

>>> Ah, but what happens when you apply pressure to it?  One would expect an
>>> increase in system pressure in this case.

>> It never sees pressure in operation - it's hooked to the air mass sensor
>> plenum chamber.

> Altitude compensation?

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

> > > 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.

> 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.

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.

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".

--
 Phil Payne
 Phone: +44 385302803  Fax: +44 1536723021  CIS: 100012,1660