[urq] MB engine boost & MTM mods

[Johan H]

Hi Guys,

I think I have asked something regarding this same thing before, but now I'm 
hoping to understand everything. I was going through the archives and found 
the below texts about the very same car I bought last spring.

I am wondering if one of you experts could tell me what the standard boost 
is for the MB engine? I found mentions of 0,69 bar but also Phil Payne 
saying the standard boost is 1,53 to 1,59 (see mail below)

In the mail there is also explained what is done to my engine, does someone 
know what the Peter Link EPROM is? (have a look in the mail below) Do you 
guys think the mods made to my engine is "safe"?

Cheers,
Johan Hisinger
Helsinki, Finland


My '88 MB Urquattro MTM ECU has a modified fuel-ign map chip and a
resistance on the output of the pressure sensor, along with a significantly
stiffer spring.  I run around 1.8 to 1.85 bar with no detonation, will try a
little more boost in the spring.

I think tomorrow I'll hook up the Bosch PMS100 oscilloscope to see how the
WGFV works on the MTM ECU.  I'll be interested to see how Peter Link
programmed the WGFV into the equation.  My spring preload is so low the the
WGFV should have a noticeable effect.  I've got to figure out how to record
boost/rpm on the oscilloscope - I guess I'll need to install a boost gauge
with an output to the scope.

Maybe I should be scoping the lone knock sensor...

Jouko Haapanen
Pori, Finland


----- Original Message -----
From: <isham-research.freeserve.co.uk at pop.pol.net.uk>;
<phil at isham-research.freeserve.co.uk>
To: <Sargent at SymposiaFoundation.org>; <quattro at audifans.com>
Sent: Sunday, December 05, 1999 12:00 AM
Subject: Re: toasting an O2 sensor, hesitation at boost, and more


To: "Phil Payne" <quk at isham-research.demon.co.uk>, <Anders.J.Ahlin at telia.se>
Subject: Re: MB/1B engine questions
From: "Jouko Haapanen" <joukoh at vtoy.fi>
Date: Sun, 31 Oct 1999 21:56:23 +0200
Cc: <quattro at audifans.com>
Sender: owner-quattro at audifans.com

--------------------------------------------------------------------------------

Phil,

This is an old thread-reply of yours from just over 1 year ago.  In cleaning
up my own archives, I find this interesting as currently I'm running an ECU
with an EPROM Peter Link at MTM made for my car (EPROM only, no other
changes).  I get max. boost of 0.69 bar now (digital manometer, accurate)
like clockwork.  The EPROM will be joined by a change to the boost sensor in
the form of a resistance to the output and an optimizing WG spring pressure
for the changes while avoiding our friend pre-ignition/detonation.  All
changes are done step by step with thorough on the road testing with two
sets of ears in stethoscopes leading to the valued new head whilst driving.

I've put my faith in MTM (or actually Link) after much deliberation.  I'm
looking for a modest increase in power, but more than that, already even
with the boost sensor still unmodified and stock spring pressure, the car
runs much stronger with better mid-range torque with only fuel/ignition
remapping.

Jouko Haapanen
Pori, Finland



-----Original Message-----
From: Phil Payne <quk at isham-research.demon.co.uk>
To: Anders.J.Ahlin at telia.se <Anders.J.Ahlin at telia.se>
Cc: quattro at coimbra.ans.net <quattro at coimbra.ans.net>
Date: 22. syyskuuta 1998 13:37
Subject: Re: MB/1B engine questions


>In message <H000122d009fb153 at MHS> Anders.J.Ahlin at telia.se writes:
>
>>pure curiousity, but do you have the following (stock) values for:
>>
>>- MB/1B engine max boost
>>- MB/1B engine max torque @ rpm
>
>Finally found the MB values:
>
>Boost is 1.53 to 1.59 bar at sea level - 1.73 to 1.79 at 2400m.
>
>Torque is 270Nm at 3000rpm.
>
>(Wouldn't mind trying a few percent more boost now I've got the fuel
>sorted out.  Any QLCC members listening?)
>
>--
>Phil Payne