Running stock 67-72 Tach with an LSx?

[Puropedo]

Hey guys, is this possible? I would love to keep all my stock mechanical gauges working, so far I have figured oil,temp,volt and speedo.....

[ls1nova71]

Yes you can. You will have to have the tach resolution set from 6 to 3 in the tune. You can do it with HPTuners or have someone who does tuning do it for you. What this does is double the tach output, since Ls engines put out a 4 cylinder output. Otherwise your tach will read half of what it should.

Also if you're using a 2003 or newer PCM, you may need a pull up resistor to make the signal strong enough for the tach to see it.
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[John @ BROTHERS]

Originally Posted by ls1nova71

Otherwise your tach will read half of what it should. Posted via Mobile Device

So theoretically, the stock 5k tach will be a 10k tach?
Thanks,
John

[ls1nova71]

Originally Posted by John @ BROTHERS

So theoretically, the stock 5k tach will be a 10k tach?
Thanks,
John

I suppose if you were to change the numbers on the lens, then yes it would be! Lol
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[HavinSomeFun]

What did you do to figure these out? How did you do it? I found some metric to standard adapters for the temp and oil psi..is that what you used or?

Originally Posted by Puropedo

Hey guys, is this possible? I would love to keep all my stock mechanical gauges working, so far I have figured oil,temp,volt and speedo.....

[Puropedo]

Originally Posted by ls1nova71

Yes you can. You will have to have the tach resolution set from 6 to 3 in the tune. You can do it with HPTuners or have someone who does tuning do it for you. What this does is double the tach output, since Ls engines put out a 4 cylinder output. Otherwise your tach will read half of what it should.

Also if you're using a 2003 or newer PCM, you may need a pull up resistor to make the signal strong enough for the tach to see it.
Posted via Mobile Device

Sweet!...Thanks for the input brother!

Originally Posted by HavinSomeFun

What did you do to figure these out? How did you do it? I found some metric to standard adapters for the temp and oil psi..is that what you used or?

I drilled and tapped the boss above the oil filter for oil pressure, drilled and tapped the hex bolt for temp, tail housing kit for speedo, also, I simply applied power and ground to the voltmeter, hope that helps!..