Advanced Help needed, Tach signal Modification... RB and others

[datsunmotorsports]

Im looking to take a low voltage signal and amplify/clean it up to operate a S30 tach. Specifically Im trying to modify the signal from PIN 7 on the RB25DET ECU. I got the idea from the MegaSquirt website as I run that system on one of my other cars.This is what Ive come up with.

Find yourself one of those GM HEI modules. The ignitor unit as it is often called.The particular unit I use is the 4 pin one. Im sure the others could be used but I dont have the pinouts for them.

W - GroundG - Input from MF01 thin yellow/blue stripe that goes to pin 7 on the ecuC - To TachB - Ignition/Power Source B+

Before you go connecting this maybe someone with more electrical experience will chime in and help out.

Also Note that this will work for the 3 wire tachs and those with 4 wires(the one with the loop) will have to figure this out on there own.

Ive used this on 280ZX turbo motors with the stock coil system. I also used it briefly on a DC EGR signal from the LD28 engine. The LD setup was closer to what Im doing now with the RB.

Thanks for input

[XJared]

Did this work for a stock 280ZX tach or was it ever tried?