TomX8

We have the problem that we can't read the RPM signal. It does how on the dashboard, but we need our external ECU to be able to read it, but since it seems that the signal voltage is too low to be detected, we can't make progress.

Where can we get the RPM signal from? It has to be readable by the external ECU/Computer.

I did found that I could read it out with our ELM327 in combination with any OBD2 app on the Phone, via bluetooth tho, so there must be a way.

wankelbolt

iTrader: (21)

The tach is driven by the ECU via CANBUS data signals as is the ELM327. They do not have a discreet, traditional tach signal. The ECU reads eccentric shaft position sensor to determine engine RPM and sends it out over the CANBUS to the instrument panel. I don't think there is a tach signal that can be tapped in to.

Maybe the best way to get a traditional tach signal:
http://www.msdperformance.com/Produc...Ignitions.aspx

TomX8

This might be just what we need!

So basically they are sent in digital form, instead of analog? What kind of signal is it exactly?

9krpmrx8

iTrader: (46)

You have to get it from the coil wires. If you search for here for "Greddy RPM" you will find some threads on people using the Greddy product.

GReddy 15900909 RPM Signal Adapter #3 Mazda RX-8 All 2004-2011

TomX8

Thanks 9k!

Is there anything available in Europe? I am still searching and so far I can't find anything in the EU, only in the US.
It would make it alot easier with payment and shipping.

TomX8

Can we also tap into the coil?

Or is this from where the signal is too weak?

If I get only 1/2 of the signal, can I tap into both the front and rear rotor Leading Coil and combine these 2 taps into 1 wire so I get the full signal?

The RPM reading is for the piggyback ECU.

dannobre

iTrader: (3)

What ECU? It will need to be able to read the shaft trigger to work properly anyway