[urq] First of many urq questions

Buchholz, Steven Steven.Buchholz at kla-tencor.com
Fri Apr 2 19:14:25 EST 2004

... well, it is interesting to note your seemingly contradictory statements
... you didn't want to switch to an MC because of the complications ... but
then you want to graft in a control system from a completely different

I too had considered the possibilities of incorporating the APC system ...
but after I went round and round with it I realized the same thing you did
... how do I determine what locations would be valid for the installation of
the knock sensor?  There's another thing to consider ... the WX has solid
lifters, which must be kept in proper adjustment to prevent setting off the
knock sensor.  What I ended up deciding was that if I indeed wanted to
incorporate knock detection in my car, the best solution would be to go with
an MC engine and control electronics.  The added benefit in going this way
is that the MC engine control system has a means to limit boost as well as
timing should a severe knock situation arise ... 

If it isn't too late to change direction on the WX swap would be to give
serious consideration to finding an MC engine ... and my recommendation
would be to find an MC-2 engine with the K24, higher static compression
ratio and dual knock sensors.  You will need to do a bit of work to
determine exactly how much of the 200T's wiring harness you will need to fit
into your car.  I suspect that you should be able to find a point where you
will need to splice in very few signals ... +12 switched, ground, tach ...
but I have to admit the possibility of having a trip computer makes me tend
to complicate the thing ... 

Steve B
San José, Kaleefohnia (USA)
> We're replacing the engine in our '84 urq - it spun a bearing last
> summer, and after the head was also found to have cracks we gave up on
> the idea of rebuilding, and are putting in another known-good WX
> engine. I know an MC would also be a good choice but I wanted to avoid
> replacing all the FI and engine wiring.
> One thing we're wondering about is the idea of installing a saab apc
> system on the wx. Simple enough in principle (though quite hard enough
> for me), and looking through the archives there are some apocryphal
> reports that it has been done before ('83 urq) but no real details. To
> start with I can't see where one could mount the knock sensor. My wife
> Jenny (the true owner of the urq - I just get to work on it) asked on
> the main quattro list, but there were no responses. I was hoping
> someone here might have some ideas. There is a good-looking mounting
> boss on the block next to #5 cylinder, just by the heater pipe, but I
> wonder if that would work well enough. I'd think #3 would be a better
> position to detect any knock.
> Any thoughts appreciated even if "thats a stupid idea"!

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