I have this sunpro supertach rpm gauge i have everything it came with cause it was brand new in box. But not sure how compatable it is with a rotary motor because it has a switch to change between 4,6,8 cylinders. Anyone got any advice for me?

 

It should work just fine set on 4 cyl. Are you replacing the stock unit or just throwing it in for the sake of a few laughs?

 

My rpm gauge stopped working cause i went turbo with a standalone. I am running two msd 6al's the standalone is plugged into one and im gonna plug it into the other one. Just wondering if it will read the rpms right or not?

 

are you running aftermarket coils? where is your standalone getting a tach signal from? i went large turbo w/ standalone and msd box and my tach still works.

 

If you ditch the coils it'd make sense. But yeah it should work just fine on a 4cyl mode. You could probably hook up your original tach.

 

Im using the stock coilpacks from my 86. I plugged it in to the top of my msd tonight on 4 cylinder and it gets the rpm signal from it good. I tried using the stock rpm guage but it just wont get signal to it idk whats the problem. I been getting random wiring problems since the build like my reverse lights stay on when the cars on cant figure it out so just took out the bulbs haha.

 

That doesn't sound good. I wonder how the wired up the coil packs, they probably disconnected the original tach feed. I believe it's yellow/blue at the trailing coil. I'd probably start looking into what other wiring they fubar'd!