electronic distributors

[gofast at ix.netcom.com]

Thanks for all the responses on the octane/ignition issue with my BMW 530i. 
I think I am beginning to understand my problem. Here's what I've gathered.

The old 77 bmw 530i came with thermal reactor emission system. As a result, 
the base FI was set up to run very rich at idle, (so it could be induced to 
burn in the thermal reactors with the air pumped in by the air pump), and it 
had a really lazy distributor, that did not advance very far (32 deg @ 3500 
rpm, 22 deg at 1700 rpm). With all my emmisions crap off, and the higher 
compression, I need to run this thing with more advance. Also, I've been 
told that BMW piston ratings were optimistic - BMW 9.5:1 is more like real-
world 8.8:1, so I should be OK with 93 octane. So, thanks for all the octane 
enhancer stuff, but thats probably not the problem.

If I set the advance to 38 degs max, lets say, then I will not be able to 
idle well, as the mixture, set by the computer, is too rich. I thus need to 
retard the timing more at idle. The short of it is I need to change my 
distributor curve, and, possibly, my ECU as well. The best solution, I'm 
told, is to use the entire FI system from a 79 528i. A used FI system will 
probably set me back $400-600. 

An alternative is to use an Euro Bosch BMW mechanical advance distributor, 
which has more advance. $300!

Another alternative is to get someone to recurve my current distb's advance. 
Bob McElroy mentions this. Does anyone know/recommend where I can get this 
done? I live in Stamford, CT.

I have access to a 79/80/81 BMW 528i electronic distributor. Can I make/buy 
a control unit for it that will advance timing with rpms?

Or, is it possible to get a programmable aftermarket electronic distributor 
to manage timing advance and retard based on engine rpm input, so I can 
retain the injection parts of the system while adding electronic ignition 
control.

In the meantime, I will drive with the timing light attached and fuel 
pressure meter attached, to see what further information I can gather. Am 
also building a o2 sensor led meter, as per projects page.

Thanks.


Samir Shah
gofast at ix.netcom.com
Stamford, CT