Tach Chip?

citrus3000psi · Post by **citrus3000psi** » Tue Feb 09, 2010 12:39 pm

So I finally picked one of these up,

90 eclipse coilpack with the tach adapter chip. So now how do I wire this thing? Looking at the back of the chip, there is three connections. IN, IN and OUT.

Is it as simple as just hooking up the two "IN" to the coil pack and the "OUT" to the tach?

I've looked at the wiring diagrams for the ram50 but I'm still unsure which wire is the tach input. Any help would be great.

Thanks
Dan

2.3strokdtalon · Post by **2.3strokdtalon** » Tue Feb 09, 2010 8:16 pm

If I remember correctly, then yes, it is that easy. Yellow wire to your tach. Done.

Egoinstigator · Post by **Egoinstigator** » Wed Feb 10, 2010 11:43 am

I will try this this weekend on my 4g63 swap. If this works, I won't have to do any more modifying of my Megasquirt to get the tach to work.

Good stuff.

4g63mightymax · Post by **4g63mightymax** » Mon Feb 15, 2010 11:51 am

If you are using a stock mightymax / ram 50 tachometer cluster:
You will all quickly realize once you hook up the 90 DSM coil that the tach cluster is meant for a truck with a distributor. So the cluster wants to see twice as many ignition pulses as the DSM coil pack wants to hand out. Thus, the tachometer will be totally inaccurate once it is all hooked up.

Bummer right?

I recommend messing with it to try to get the tach working right. I did for a long time with varied results. Eventually I got sick of shocking myself and mated the DSM and mightymax clusters together for the ultimate win.

Biggity Bam. Be sure to post your results. I am interested to know if anybody can figure this out without using a DSM cluster.

-Jeremy

citrus3000psi · Post by **citrus3000psi** » Mon Sep 13, 2010 10:02 pm

I wanted to post up what I finally ended up with. I took jeremy's advice and didn't even mess with the 90 coil pack and tach chip. I decided to drop in the eclipse tach into the ram50 cluster. My issues where the 92 turbo cluster tach has a much shorter sweep then compared to the ram tach. I wanted something that kept the stock face of the ram 50 but accurate at the same time. I ended up getting a tach from a 1g eclipse nt w/2.0. The tach is the same input type as the turbo and a has a mucher larger sweep thats very close to the ram50.

Richard · Post by **Richard** » Thu Sep 30, 2010 6:57 am

I think it should be possible to mod the tach itself.

I know it's possible with a Starion Tach as i've done so myself.

I'll post a small how to for those interested.