RE: NA I-5 performance suggestions (WOT enrichment devices)

[Henry Harper <hah@srv.net>]

> Date: Wed, 11 Mar 1998 11:45:40 -0500
> From: "Smith, Kirby A" <kirby.a.smith@lmco.com>
> Subject: Re: Re:
>
>  ejfluhr@austin.ibm.com (Fluhr) commented re:
>
> >>> I'll bet someone on this list has a plan they
> >>>could share for a full throttle enrichment device.
> >>Funny you should mention this, but I'm planning to fool around with
> this
> >> myself after reading about Techtonics Tuning kit for the Scirocco.
> In
> >> theory its very simple.  Temp sensor is wired in series with another
> >> resistor which is shorted by the NC contacts of a relay.  When you
> hit WOT,
> >> the relay cuts in opening the contacts and putting the "enrichment"
> >> resistor in the circuit.  ECU gets fooled into thinking the
> temperature is
> >> colder and compensates by bumping up the current to the differential
> >> pressure regulator.  The fun comes in determining the value of the
> >> enrichment resistor so you don't go overboard and go past 12:1 F/A
> ratio.
>
>
> >Doesn't the Wide Open Throttle (a.k.a. full throttle) switch achieve
> this
> >function on CIS-E cars?
>
> >I recall reading somewhere that when the ECU sees the WOT switch close,
> it
> >goes open-loop and bumps the pressure actuator current by ~3mA,
> effectively
> >enriching the fuel mixture (slightly).
> >
> >I assumed that the CIS-E "chip" mods offered by TAP, etc. just
> reprogrammed
> >the actuator current increase on WOT to a higher value.  This gets you
> closer
> >to 12.6:1 without much danger of going over-rich.
>
> On my 1988 90q, at modest driveway rpm, closing the WOT by hand has no
> effect on the pressure actuator current.  I have heard that on this
> model, the WOT only disables the air conditioner compressor.  I believe
> the 1988 90q uses the NG engine with CIS-E.
>
>

I haven't looked carefully at the A2 VW 8v CIS-E, but I believe Bentley states 
for my A2 VW 16v CIS-E the WOT switch bumps the mixture only above 3k rpm. So 
you wouldn't see anything at "modest driveway rpm" if that's under 3k. The AC 
compressor on this car also does not shut off by the WOT switch, but usually by 
the time I wind through 1st and part of 2nd at WOT it will cycle off from 
having lots of revs make good pressure/cooling.

Still interested in a TT device for that car even though the _ec_ test showed a 
gain only above 5k, (it was 11hp @ 6k).

Henry Harper
http://www.srv.net/~hah
1991 200 quattro, 86k, mo-mo-motronic, one ROM in one box instead of the two in 
two separate boxes I swapped in Dad's 951 last week
1988 GTI 16v, 174k, CIS-E, separate boxes for ignition, knock control, and 
mixture, unchippable but maybe fool-able