re. How do I get past 1.8 bar?

[ben swann]

Jason,

You are good to about 17 PSI before having to add fuel with a means
such as the 034EFI supplimentary injector controller, or water
injection.  I set mine at 16 and never had a problem.

The easiest method is to use a variation on the resistor mod in
conjunction with QLCC chip.  resistor is inserted between pins 1 and 10
on the pressure transducer inside the ECU - I ran leads outside of the
ECU and installed a knob to control it.  Using the variable resistor,
you can raise the limit of the boost cutoff to match the boost you have
dialed in.  The total resistance value can vary, but would be around 4K
ohm - use the variable pot( eg. 5k linear taper) in series with another
(~650 ohm) to set a safe limit as you don't want the resistance to be
near zero.

The boost can be achieved in a number of ways:
1) a stronger wastegate spring (simply shim the 1.8 bar spring you have
to make it mor like a 2 bar spring, or get a 2 bar spring.)

2) use pressure regulator to control the wastegate "schrapnel knob" to
adjust to desired amount of boost.  Frequency valve control may be
disabled.  Here is a diagram of my implementation:
http://www.homestead.com/ben_swann/files/Vacuum5kt.jpg

Other stuff on my aging site may be of interest - one of these days
I'll get around to update it:
http://www.homestead.com/ben_swann/myaudi.html

Hope this helps.

Ben

[From: "jason snider" <jason_chad at hotmail.com>
To: quattro at audifans.com
Subject: How do I get past 1.8 bar?
Date: Sat, 31 May 2003 15:19:16 +0000

Dear fellow Audi enthusiasts:
    I have an '86 5ktq with a QLCC 1.8 bar chip and a stiffer WG
spring. I just installed a Forge BPV and I want to add some
boost...goal is a safe 15 psi. From what I could get from the archives
this is the limit of the fuel system, correct? I have an adjustable WG
cap as well as a pressure regulator ready to be used, but which one
would provide quicker spoolup? Which would be safer? As for the fuel
pump cutout I have a 470 ohm resistor]

**** use this 470 ohm resistor in series with the pot. as I explained
above.  Calibrate to around 4Kohm and you should be good for about 2.2
bar....BEN

[but I don't feel comfortable opening up the ECU. I was thinking about
grounding the fuel pump
wire and installing a toggle switch inside the car so I could still
have the cutoff when I am not using the extra boost. Does this sound
like a good plan? I suppose I could find someone to put the resistor in
if it doesn't work. I'm done with school for the summer and I'm not
working yet; so I've been looking for cheap tricks for power :) . Gonna
do the timing advance tomorrow. At least I have plenty of time to work
on the money pit now.
Thanks,
Jason]