Running OEM tach from Sniper EFI w/Hyperspark

[kaj750]

At some point, in a random thread, I THINK someone helped me out with this, but can't find the info after two days of searching.

1969 Dodge Charger
Sniper EFI
Hyperspark distributor
Hyperspark coil
Hyperspark (CDI) ignition box
Sniper PDM
Rallye dash with OEM tachometer

There is no tach output for the OEM tach.

Has anyone done this? I think I need to install a Holley input/output harness then maybe a tach conversion box or something or other.
... Though I don't think my sniper harness has any more open plugs.

Input for my output problem? Lol

 

[kiwigtx]

You should have a brown wire that can be used for the Factory Tach from the Sniper unit....

Does that help you at all @kaj750 ?

 

[kiwigtx]

Actually the instructions say "Aftermarket Tach" ....so if that doesn't work, you might need the Holley Tach Adaptor Part #8920

You don't need the MSD to run a tach adaptor.

 

[kiwigtx]

Have a read here also - a Holley Tech forum thread....

https://forums.holley.com/forum/hol...hread-about-hooking-up-the-tach-to-the-sniper

 

[kaj750]

Actually the instructions say "Aftermarket Tach" ....so if that doesn't work, you might need the Holley Tach Adaptor Part #8920

View attachment 1722983

View attachment 1722986

You don't need the MSD to run a tach adaptor.

I have that part on order, just in case. Looks like I can run the switched power source from the spot on my PDM where the sniper ECU gets it. I can run ground to the same. Then I use the sniper tach wire into the converter then out to my gauge cluster. I hope it's that simple.
I don't have an MSD box nor a regular coil, so it gets tricky.

 

[BeepBeepRR]

If you do run it without the tach adapter your RPM's will base out at about 4000 rpms. You need the tach adapter to fix the issue from going analog to digital. Your OEM tach is analog and the sniper puts out square wave. The adapter corrects the pattern for your analog gauge.

 

[kaj750]

If you do run it without the tach adapter your RPM's will base out at about 4000 rpms. You need the tach adapter to fix the issue from going analog to digital. Your OEM tach is analog and the sniper puts out square wave. The adapter corrects the pattern for your analog gauge.

Perfect, thank you.

I believe I'm on the right track with the part number suggested above.