re: Re: User-programmable engine computers

[walter@quattro.corp.inmet.com (Walter Meares)]

> 	Has anyone tried to use the Haltech, Electromotive Tech II, or similar
> EFI systems on a streetable Audi?
> 

How would you integrate it with K-Jetronic/Motronic?  Haltech's designed to
read sensors and drive pulse-type injectors.  It's oriented toward a 
speed-density approach: looking up a base pulse width based on rpm and
manifold pressure and modifying the pulse width to adjust for other
sensors (eng temp, air temp, etc).  K-jet systems are "mostly" metered by
the air mass sensor in the fuel distributor, and fine-tuned by "diddling" 
(somebody else used that word, I like it) with the fuel pressures.  If there
are ROM lookup tables in an Audi computer, I don't know what they'd be used
for, except for the aforementioned diddling and ignition timing.

You'd have to replace the whole $y$tem to use this, I think. Maybe you could
set up the Haltech to diddle the differential pressure regulator, or frequency
valve, or whatever the equivalent on the K-motronic cars, but it's a lot of 
computer horsepower for that task.

Do any Audis use a pulsed injection system?  The Haltech would work alright 
for that.  I don't have any specs on the Electromotive Tech II.

By the way, last time I checked, a Haltech was either $800 or $1100, depending
on which one you bought.  The was about a year ago.  I was planning on building
a new motor for my 260-Z, and I thought about replacing the carbs with EFI.  But
between the computer, manifolds, throttle bodies, injectors, wiring... it looked 
like $2k for the EFI alone.  I bought a junk Z for $250, with the L-jetronic 
EFI already on it.  Now using that as a base, plus something like a Haltech, might
be a little more acceptable, price-wise.  But since I already spent $$$$ replacing
seats, carpets, doing minor engine work, stripping and repainting the car (ever 
priced car paint? ouch!), replacing rubber seals ($130 for each door seal!), not 
to mention tools, I think the engine rebuild will have to wait a while...

Sorry about the off-charter Z stuff, just wanted to place the Haltech info in
context.

Walter

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