[200q20v] boost controllers

[Brett Dikeman]

At 8:09 AM -0600 7/24/00, Brian.Link at Level3.com wrote:
>Has anyone installed an after market boost controller?

No.  And don't :-)

Audi and Bosch spent years on the Motronic engine management computer 
and it's based off almost(or more than) half a century of experience 
with engines.

The boost controllers are based off brute force technology.  They are 
'dumb' compared to the advanced tables, sensors, and adaptive nature 
of the Motronic(not to mention, the advantage of having mixture, 
timing and boost control all done by one unit.)

Don't go replacing(or overriding) the ECU with a $300 piece of junk 
when 20v turbo engines run $3500+(that's if you can find one.)  If 
you look at the boost controllers and the guys who use them, they 
compensate for lack of boost control complexity by changing the 
timing(in a fixed way), and by using massive intercoolers.  Our cars 
use smaller IC's and much more intelligence; the Motronic box 
monitors, and bases its various "decisions" based on coolant temp, 
intake temp, boost, O2 exhaust percentages, throttle position, 
knock(2 sensors), engine speed/crank position.

The only units which match that kind of functionality and complexity 
are race engine management computers that allow for full programming 
and logging.  They are -very- expensive, as can be the programming 
mistakes :-)  I bet they're serious fun to play with though, if 
you're careful and know at least a little about what you're doing :-) 
I think some of them will even "learn" the stock ECU, by monitoring 
the same outputs.

As for the stumbling, it might be a toasted O2 sensor.  They last 
around 60k miles, never more than 100k.  There are a lot of other 
possibilities though, like intake leaks.  There are probably at least 
a dozen things that affect high boost performance.

Get a pro mechanic to look the car over, and/or read the Bently and 
Scott M's site and check each sensor/item you can; some of them take 
all of a minute or two to verify.

Brett
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Brett Dikeman				Systems Engineer
iClick, Inc					914-872-8043
120 Bloomingdale Rd.			914-872-8100(fax)
White Plains, NY 10605			http://www.iclick.com