Dakota Digital tacho signal modifier

Anyone have a working one that I can buy?

What are you trying to do ? What management and what tacho ?
All else fails you can get a trigger from the neg side coils via a circuit into tacho..

At this stage OEM RB25 signal into R31 tacho (not yet sure exactly what the tach needs to work...) but I should probably get the Link wired in first and see if the 12v signal on that will drive the tacho. Else I'll need something that can put out more voltage (if its a high drive tacho)

R31 tacho is a back emf type trigger tacho. RB25 ECU tacho out is totally different.
Id would use a coil neg back emf circuit to drive the tach.

I have a r33 instrument display, can you use it at all ? May be the easiest to make work..

http://www.haltech.com/wp-content/uploads/2013/07/Relay-Wiring-for-Tacho-Output1.pdf

Ok, little bit more information after fiddling around last night.

The RB25 ecu rpm output signal is ground (0v) pulses. Not 5v like some forums say - measured it last night. In other words GND - open - GND - open etc.

I tried the 5-pole relay circuit that you posted Barry but it didn't work.

The R31 revcounter signal originally came from the ECU as well from what I can figure out, but I don't know what that signal was...

I'll try my best to make the stock one work, if that fails then I'll appreciate the R33 cluster option, swop the revcounter internals over into my cluster. Thanks Barry!

Not needed anymore, got my rev counter working!

How?

Built the 'wasted spark tacho booster' from the Dicktator website using a VW TCI unit (TP100) from Goldwagen and a 5-pole relay without the internal switch.

This won't work for a RB25 in a S chassis as the rev counter in that is set up for a 4-cyl.

nice dude out of the box thinking right there

SonOfAnarchy ZA wrote:

nice dude out of the box thinking right there

Yup good friend of mine who is a whole lot more electronically minded advised me to try this. Also, R320 worth of solution vs R1900 for the signal modifier is a winning situation!