Tach wire location ???

[xile6]

I searched but found nothing.
Currently looking though long wiring diagrams.

Does anyone know where the external tach/rpm wire is for these cars?

normally it can be grabbed from the obd2 pin out but im not seeing it on these cars.
No dizzy so cant grab from there either.

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[bikejog]

I searched but found nothing.
Currently looking though long wiring diagrams.

Does anyone know where the external tach/rpm wire is for these cars?

normally it can be grabbed from the obd2 pin out but im not seeing it on these cars.
No dizzy so cant grab from there either.

Do you need the analog signal? If so, I can't help you out. But you can get the digital RPM value from CAN msgs. Buy a Bluetooth ELM327 ODB2 adapter. The ELM327 protocol is open source. The ELM327 adapter will simply show up as a Bluetooth UART port. You then send an UART msg to read the RPM and it will reply back with the RPM value.

 

[xile6]

Do you need the analog signal? If so, I can't help you out. But you can get the digital RPM value from CAN msgs. Buy a Bluetooth ELM327 ODB2 adapter. The ELM327 protocol is open source. The ELM327 adapter will simply show up as a Bluetooth UART port. You then send an UART msg to read the RPM and it will reply back with the RPM value.

Yea analog signal.
Custom shift light install.

 

[bikejog]

Yea analog signal.
Custom shift light install.

Just get an ELM327 OBD2 and learn to code. It's super easy.

But no seriously. Why not just pick it up from a plug wire? I will see if I can find the RPM sensor, but it might not one because of the electronic ignition. It might just calculate it from the coil timing.

 

[Volksparts]

Yea analog signal.
Custom shift light install.

I run a Holly shift light which has a built in tach. I setup my shifts to go off at certain rpms for each gear. It plugs right into the obd port. What I did was buy like a $15 1 female 2 male obd harness from Amazon so that it looked factory. There was no need to tap into any wires.

 

[xile6]

Just get an ELM327 OBD2 and learn to code. It's super easy.

But no seriously. Why not just pick it up from a plug wire? I will see if I can find the RPM sensor, but it might not one because of the electronic ignition. It might just calculate it from the coil timing.

Yea thats what im finding out on these.
I normally grab for the dizzy and route into the car.
My last car the obd2 port had the rpm wire in it.

But looks like i might have to grab it from the coil. Which i wasnt trying to do.

And dont care to use the elm i have tunerview.
But my custom setup is much better

 

[bikejog]

Yea thats what im finding out on these.
I normally grab for the dizzy and route into the car.
My last car the obd2 port had the rpm wire in it.

But looks like i might have to grab it from the coil. Which i wasnt trying to do.

And dont care to use the elm i have tunerview.
But my custom setup is much better

You can do that with a Raspberry Pi Zero for about $5 plus a USB Bluetooth dongle. Write code to grab the RPM value from ELM327 (or KTuner/Tunerview if that's possible), then output a PWM representing the RPM

 

[xile6]

This is what i run
Chipernut shift light. 16 leds fully customizable. And very small.

I ran it on my other car for some years and really like it. So moving it over to this car.

Already designed and 3d printed a casing for if.

Ill check out the usb to adruino.
I am fair at writing code. Just seems like it would lag with all the processing.

 

[bikejog]

This is what i run
Chipernut shift light. 16 leds fully customizable. And very small.

I ran it on my other car for some years and really like it. So moving it over to this car.

Already designed and 3d printed a casing for if.

Ill check out the usb to adruino.
I am fair at writing code. Just seems like it would lag with all the processing.

I didn't even thought of the delay. ELM327 defaults to 9600 BAUD so you'll def get the RPM in less than 50 mSecs. Then it's just a matter of changing the next PWM period to match. So I don't think there'll be any lag. And you can change the BAUD to 115.2K I believe. Unless there will be bad lag inside ELM 327 but probably not.

I know nothing about KTuner.

 

[xile6]

Just an update.
I ordered a GMR pickup. Basically clips over the coil wire like a timing light and outputs the 12v pusle.
Ill update when i get it to let everyone know if it works or not.

 

[bikejog]

Just an update.
I ordered a GMR pickup. Basically clips over the coil wire like a timing light and outputs the 12v pusle.
Ill update when i get it to let everyone know if it works or not.

Woohoo! I don't see why it wouldn't work.

Is the shift light purely for looks or are you some kind of racer?

 

[xile6]

Woohoo! I don't see why it wouldn't work.

Is the shift light purely for looks or are you some kind of racer?

Semi both. I like the look and it set normally set for 4.9k to shift rpm. So day to day it wouldnt light up.
And i plan to tuck it so it will all look factory.

Havent taken this car to the track yet. Was suppose to go last friday with some friends but didnt make it.

 

[xile6]

Just an up date. Part came in and wanted to see if it work.
Messed around for a few minutes to test it out.

So far it seems to work.
Didnt get to rev it up to see if the rpms follow.

Its like 110F outside and probably hotter in the garage.

Ill get it all setup and installed sometimes this weekend when i have more time and its not burning hot.

The leds werent hook up. Just wanted to see of i could read the rpms.
Was reading way off (the 189rpm) but thats what i love about the shift light its fully adjustable so was able to match idle rpm with tunerview.

All will be tucked and clean up just wanted to report my testing for now.

 

[xile6]

Project finished all came out and works great.

Just a little video test video.

Warning very bright light.