Are the 60-2 impulse wheels interchangeable?

[Whizbang]

Are the E30 M42 60-2 wheels the same as the E36 M42 60-2 wheels for the crank VR signaling? Trying to trace through any reason why I am having issues with my AEM EMS4 install.

[Johjamkep]

I’d say so but whatever you use, the gap is pretty much the most important. I do know that when I installed a Haltech Elite 750 ecu onto an S38, I ended up having to use a crank sensor from an M52/M54 because for whatever reason I could not get a good, stable signal from the style of sensor you are trying to make work, even though the older sensor & trigger wheel seemed like it would be an obvious choice. I used a stock M30 trigger wheel on the front. 1.5mm gap worked best.


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[apexspeedtech]

I’d say so but whatever you use, the gap is pretty much the most important. I do know that when I installed a Haltech Elite 750 ecu onto an S38, I ended up having to use a crank sensor from an M52/M54 because for whatever reason I could not get a good, stable signal from the style of sensor you are trying to make work, even though the older sensor & trigger wheel seemed like it would be an obvious choice. I used a stock M30 trigger wheel on the front. 1.5mm gap worked best.

What happens with many aftermarket ECUs is they have trouble with the magnetic crank sensors on a 60-2 trigger wheel, as they put out a modified sine wave output whose voltage is proportional to engine speed. At some point, if the system doesn't have the sophistication to change trigger levels and hysteresis, they're just not very resilient.

The M52/M54 crank sensor is a an active "hall-effect" sensor which outputs a square wave and can eliminate these issues, but not always.

If you're having issues with a 60-2 crank (all BMWs, Porsches, VW's since the late 80's) try converting to a different crank trigger. If you have a distributor, you can use the AEM EMP:

http://www.aemelectronics.com/products/ignition-components/engine-position-module-epm

If not, adapt a trigger wheel and come up with a mount to fit behind the harmonic balancer, I'd use the largest diameter 12 tooth option here:

https://store.vacmotorsports.com/vac---universal-race-grade-crank-trigger-wheels-p1998.aspx (http://www.aemelectronics.com/products/ignition-components/engine-position-module-epm)