5 GT Turbo Renix ignition module tacho output

[Neal R19]

Alright all, does anyone have any info about what is the form of the tacho feed from the renix module to the cluster?

On the 19 (and I guess probably others), there's a pink wire that basically goes from one of the pins on the module straight to the dash cluster to drive the tacho.

I need to know what the form of it is. Some sort of square wave? 12V pulses? Some kind of damped sine wave?

I don't have a running Renix equipped car and even if I did I don't have a scope at home!

 

[DaveL485]

I need to know what the form of it is. Some sort of square wave? 12V pulses? Some kind of damped sine wave?

It's a inverted banana wave with rainbow sprinkles.

I have no idea.

What I do know is that the Adaptronic output IGN3 won't drive the tacho, and to make it work I had to retrofit the OE ignition pack back in as well as the wasted spark coils just to make the tacho count...er...tach's
Be interested to know what you find out though. @am21t 's car is the one with that coil still fitted if you ever cross paths and want to electrocute yourself.

 

[Neal R19]

I need to know what the form of it is. Some sort of square wave? 12V pulses? Some kind of damped sine wave?

It's a inverted banana wave with rainbow sprinkles.

I have no idea.

What I do know is that the Adaptronic output IGN3 won't drive the tacho, and to make it work I had to retrofit the OE ignition pack back in as well as the wasted spark coils just to make the tacho count...er...tach's
Be interested to know what you find out though. @am21t 's car is the one with that coil still fitted if you ever cross paths and want to electrocute yourself.

I've had this cluster apart over the weekend and done my homework on it and I may be able to help you with that...

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[andybond]

@r5gordini any input ?
@Chet T16 ?

 

[Neal R19]

@r5gordini any input ?
@Chet T16 ?

Chet doesn't know, he's useless [emoji16]

However I've now ascertained that it's a basic voltage pulse from the negative of the coil

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[Chet T16]

Did your ask?

I’d guessed it’s switched ground but I don’t know

 

[DaveL485]

I may be able to help you with that...

Im listening.

 

[Neal R19]

I can drive the tacho almost directly with an Arduino now.



Dave do you know what your adaptronic puts out as a tacho signal?

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[Neal R19]

Also, just for info, the 21t boost gauge goes up to just over 1.5bar.

I do wonder how consistent this is between clusters

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[DaveL485]

Dave do you know what your adaptronic puts out as a tacho signal?

No!

 

[tutuur]

The tacho needs a high voltage spike every cylinder firing. Only works directly from 4 dumb coils or you can use a low voltage supply out of the ecu to load a coil like a relay using a pull-up circuit.

 

[Neal R19]

Yeah I've got all that working as per the video above.

Now doing the speedo... got a good (I think) plan for this.

 

[DaveL485]

The tacho needs a high voltage spike every cylinder firing. Only works directly from 4 dumb coils or you can use a low voltage supply out of the ecu to load a coil like a relay using a pull-up circuit.

I tried the relay trick but couldnt get it to work

 

[Neal R19]

Progress on the mk2 electric/analogue speedo with original barrel odo and trip.

This time the Italians have helped

 

[itzik]

Hi,

as far as i know, the AEI unit gets the RPM reading from the magnetic TDC sensor and convert it to a resistance signal (coming out from the top connector), basicley the tachometer reads the electric current that runs thrugh it, if you want to test it give it direct 12V and you will see it spike up (this how the oil pressure and coolant temp. sensors works asswell).

 

[tutuur]

I tried the relay trick but couldnt get it to work

Surely you must’ve done something wrong then as it worked perfectly on my 9

 

[DaveL485]

Surely you must’ve done something wrong then as it worked perfectly on my 9

No idea, wired it up on a 21, didnt work. Put the ign module back in just to run the tacho and it works OK.

 

[jack]

So in simple terms there's no easy way to run the rev counter with adaptronic ecu

 

[Neal R19]

So in simple terms there's no easy way to run the rev counter with adaptronic ecu

There will be, just need to scope the output and find out for definite what is coming out and something simple can be designed to suit.

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[jack]

How would I go about doing that obviously there's a pick up some where as when plugged into wari it reads the revs