[charlie66]

Originally Posted by Scott65

Charles what ucu are you using? Will it send a tach out signal? If so there should be settings that tell the tach out your firing four cylinders.

What is a ucu?

[73 TRANSAM]

Charlie,
I think he meant ECU.

[charlie66]

My ecu is Fast XFI 2.0

Thanks Ed.

[Scott65]

Yes, ecu, sorry... I'm not familiar with that system. Maybe PM Lee Atkinson. He's a FAST dealer and works with it.
Maybe this will give you a direction to look. https://www.yellowbullet.com/threads...ngine.1564626/

[charlie66]

Originally Posted by Scott65

Charles what ucu are you using? Will it send a tach out signal? If so there should be settings that tell the tach out your firing four cylinders.

I bought a little device that converts the tach to work with 4 cylinders. Ill be getting it tomorrow. The tach cant work with a 4 cyl. Its a old 8 cyl tach.

[Scott65]

That's cool. There's some pretty serious magic inside some of these ecu's.... I was envisioning the possibility of a programmable output at 2x engine speed or something of the sort. Hope your adapter does the trick.

[charlie66]

Originally Posted by Scott65

That's cool. There's some pretty serious magic inside some of these ecu's.... I was envisioning the possibility of a programmable output at 2x engine speed or something of the sort. Hope your adapter does the trick.

I hope so .

But i broke the car yesterday so thats on hold until i fix the car.

Theres always something ..

Thanks..

[Scott65]

Originally Posted by charlie66

I hope so .

But i broke the car yesterday so thats on hold until i fix the car.

Theres always something ..

Thanks..

Uh oh... Sorry to hear that. Did you get your suspension sorted before it broke?

[charlie66]

Originally Posted by Scott65

Uh oh... Sorry to hear that. Did you get your suspension sorted before it broke?

Thanks.
No i didnt.

[70GS455]

Originally Posted by charlie66

How do you calibrate it ?

There will be an adjustment potentiometer inside. If not, they are easy enough to add. Soldering and electrical circuit skills are needed.

For the input signal, V8s are 15 rpm per hz and a 4 cyl is 30 rpm per Hz.

If using 55 to 60 deg dwell, set the function generator for 65% negative dwell. 12v square wave output.

Using the frequency counter, adjust the generator frequency using the scaling above. Adjust the potentiometer to get the proper rpm readings.

May have to replace the charge pump capacitor in the tach with a different value but that is easy enough.

Sent from my SM-T817V using Tapatalk

[charlie66]

Originally Posted by 70GS455

There will be an adjustment potentiometer inside. If not, they are easy enough to add. Soldering and electrical circuit skills are needed.

For the input signal, V8s are 15 rpm per hz and a 4 cyl is 30 rpm per Hz.

If using 55 to 60 deg dwell, set the function generator for 65% negative dwell. 12v square wave output.

Using the frequency counter, adjust the generator frequency using the scaling above. Adjust the potentiometer to get the proper rpm readings.

May have to replace the charge pump capacitor in the tach with a different value but that is easy enough.

Sent from my SM-T817V using Tapatalk

Haha . easy for you to say..

I have no idea what you just said.. lol

What is a function generator?

Thank you

[70GS455]

Originally Posted by charlie66

Haha . easy for you to say..



I have no idea what you just said.. lol



What is a function generator?



Thank you

I have all that equipment as I repair tachs. May want to send it to someone who dies that type of work

Sent from my SM-T817V using Tapatalk

[charlie66]

Originally Posted by 70GS455

I have all that equipment as I repair tachs. May want to send it to someone who dies that type of work

Sent from my SM-T817V using Tapatalk

That explains it .

Sounds like you know your tachs..

I bought a tachometer converter. But now im having trouble understanding how to set it up..

[70GS455]

Originally Posted by charlie66

That explains it .



Sounds like you know your tachs..



I bought a tachometer converter. But now im having trouble understanding how to set it up..

What do the instructions say? Should just go inline with the coil- wire, there may be a power and ground too

Sent from my SM-T817V using Tapatalk

[charlie66]

Originally Posted by 70GS455

What do the instructions say? Should just go inline with the coil- wire, there may be a power and ground too

Sent from my SM-T817V using Tapatalk

Sorry i havent been on for a while .

I got it all working .

That widgit thing worked great..

[Sirrotica]

Charlie, good to know the Widget works as described by the manufacturer.

[charlie66]

Originally Posted by Sirrotica

Charlie, good to know the Widget works as described by the manufacturer.

Yeah it was easy .

Theres alot of options for other tachs as well.

Thanks for the link Man! Much appreciated!