Do I Really Need the Tools?

[Phil Payne]

> I replaced my BUZZING Bosch pump with an aftermarket Pierburg
pump($160)
> over the Xmas holidays. Even though I took my time, being careful,
it only
> takes 2 hours max, (in 15*F weather).
> The Pierburg pump will fit old and new style mounts, and runs quiet
enough
> that it doesn't need the Bosch anti-noise device bolted above the
pump
> body.
> I was told that Audi is now using Pierburg pumps as OEM in their new
cars.
> quality control over Bosch was the reason(?).

It's odd somehow to see Pierburg referred to as 'aftermarket'.
Pierburg was a HUGE name in fuel supply systems back in carburettor
days, and they supplied the fuel injection systems used in the rally
quattros.  Thess systems were CIS. but fully mechanical - you've never
seen so many setting screws and cams in your life.  The Pierburg
metering head plunger rotates rather than going up and down, with the
whole metering head moving and the lever on the plunger bearing
against a rotating cam.  It's a while since I've played with one, but
I think the movement was proportional to boost and the cam rotated
with RPM.  Audi cut separate cams for each stage.

The reason Pierburg was chosen was that they made systems fr power
boats - by law these have to be constructed so that the boat always
has enough forward motion to steer into the weather.  Great for a
rally car that HAS to get to its service area.  Idle was about 1800
RPM.

Pierburg pumps are turning up at the Audi dealers here occasionally.

--
  Phil Payne
  http://www.isham-research.com/quattro
  +44 7785 302 803
  +49 173 6242039