87 Classic VDO Tach Setting

[DamnDonzi22]

On the back side of the tach, there are setting choices a thru f. What is the correct setting for a 454/365 hp?

[BlownCrewCab]

Hmnn, I have heard of selections of 4,6,8 but not A thru F, IDK, I think we have some gauge distributers here on the board that should know.

[Pismo]

Not to be a wise a$$, but which ever one works...You'll know right away.

[DamnDonzi22]

Thats what I thought. Big difference in a couple of the settings. I have seen tach settings before, but they were always marked, 4, 6, 8, etc.. 3 of the settings have the idle anywhere from 1500 to 3200. When it is somewhere in the 800 to 1000. Going by the ear method... :) Difference on upper end is 4400 to 5400. Depending on the setting. This all started as we were playing with props and didn't seem to be getting the rpm's where they belonged. So we thought maybe the tach is incorrect. Was hoping someone had been this route before. Next step is to put a digital tach on it and compare at idle and on the upper end. Then play with props again and give her some fuel.....

[MOP]

Simple 44 sounds like a fast but not pushing 54 sounds like it is starting to scream, I would guess the 54 is 6 cylinder and 44 is 8 just guessing!!

[DamnDonzi22]

With the VDO tach on setting d, the reading on the VDO tach matched the digital tach we had hooked up.

[MOP]

with the vdo tach on setting d, the reading on the vdo tach matched the digital tach we had hooked up.

D 4 Donzi!

[BlownCrewCab]

D 4 Donzi!


or "Doh"