Rayyle Dash Tachometer conversion

[usraptor]

1970 Cuda 440 with Rallye Dash.  I converted to electronic ignition during the restoration and now my tach does not read accurately.  It seems I've read before somewhere about somebody who converts then to read correctly with the electronic distributor but can't find it.  Can somebody please provide me with that information?

[Husk Challenger]

Real time engineering maybe?

https://www.rt-eng.com

[usraptor]

Anybody else. Does Instrument Specialties do conversions?

[dodj]

What kind of ignition do you have? Factory electronic ignition works fine with the original tach.

[Chryco Psycho]

I have just purchased the kit from RTE & done the conversion myself , you do need the signal generator they sell to calibrate it as well

[usraptor]

What kind of ignition do you have? Factory electronic ignition works fine with the original tach.

I bought the Summit Racing Mopar electronic distributor/conversion kit: https://www.summitracing.com/parts/sum-851005
The tach works but according to both my timing light and dwell meter the Tach reads approx 500 RPM higher than normal.  I may be wrong, but I thought I read somewhere if the car originally had a points and condenser ignition and it was converted to an electronic ignition that the tach would not read accurately and would be need to be converted/transistorized to read accurately with an electronic ignition?   

[dodj]

What kind of ignition do you have? Factory electronic ignition works fine with the original tach.

I bought the Summit Racing Mopar electronic distributor/conversion kit: https://www.summitracing.com/parts/sum-851005
The tach works but according to both my timing light and dwell meter the Tach reads approx 500 RPM higher than normal.  I may be wrong, but I thought I read somewhere if the car originally had a points and condenser ignition and it was converted to an electronic ignition that the tach would not read accurately and would be need to be converted/transistorized to read accurately with an electronic ignition?   

They weren't very accurate to start with.  Being within 500 rpm is doing pretty well for it's age. If you want it accurate, electronic conversion is the way to go. Mine is out similar to yours. I just haven't decided on the Dakota Digital dash yet. If I decide against it, I'll go with the RTE engineering kit.

[usraptor]

Sounds like the RTE kit is the way to go.  Thanks guys!

[Bullitt-]

I stole this picture from https://www.rt-eng.com/images/8/8e/RealTimeEngTach_MoparActionApril20005.pdf

The removal of an original b-body tac I believe.. There is variable resistor, round silver thing with slot in the middle for adjusting something, top middle of pic.... I've never done but I believe there is a good chance turning this will make a difference in what your tac reads. Probably adds if turned right...  Might be worth a spin so to speak....
   Some one Please correct me if I'm wrong

[Chryco Psycho]

Most original tachs are not liniar so it may be off by 400 rpm at idle but could be off by more than 1000 rpm at 3500 so adjusting the potentiometer will not help

[jimynick]

You know lads, there IS a reason why Sun sold so many tachs back in the day....  Just sayin' 

[dodj]

You are correct bullitt. But so is CP. The end result is you can make it accurate at one point.  Idle, mid range,  top end.  Take your pick.