Currently planning a Audi AAF/7A 20v VEMS Install in a 83'Audi 80GTE quattro (4000q for you yanks :-)
AAF 2,5l 5cylnder engine
7A 20v head and intake
89' 20v tubular exhaust manifoild
S4 camshaft pulley and tensioner
VEMS gen3.3 with fully sequentional injection and COP
I am not shure if I will go with the auditrigger setup, since it seems to have some issues.
I would rather not use the distributor for timing, but it may have to do for now. I allso have another approach to the audi 3-trigger system i would like to test, as soon as I have the engine running.
Consept: The audi 20v engines have 3 sensors:
A even 135 tooth starter gear vith VR sensor.
A single tooth Crank gear with VR? sensor.
And a single window Hall sensor in the Dizzy.
The original CPU uses ONLY the single tooth crank-signal wich comes at the same times as the hall signal from the dizzy.
This, I believe is done with a gate circuit, because these signals MUST come at the same time, wich can be a pain in the ass!
This should be just as easy to do with a divider chip, set to divide by 2. Use the cam signal to reset the chip, wich then will count to 2; only the Crank-signal on the second revolution after reset gets to the CPU.
Here, the Crank sync and Cam sync must NOT overlap, as the overlapped crank-signal would be skipped.
Any ideas are welcome!