I'm thinking of installing an Auto Meter Shift light. All the kits I've seen are for standard 4, 6, or 8 cylinder applications.

Anyway they can be utilized on a Rotary?

I think the 2 rotor wankel has the same ignition pulse frequency as a 4 cyl so if the shift light uses the tach signal it will work. The tech support dept. of the unit's manufacturer should be able to help. An electronics geek could also design a light to go on with the red line warning tone but it would not be adjustable for rpm.

Originally posted by JCC
I think the 2 rotor wankel has the same ignition pulse frequency as a 4 cyl so if the shift light uses the tach signal it will work. The tech support dept. of the unit's manufacturer should be able to help. An electronics geek could also design a light to go on with the red line warning tone but it would not be adjustable for rpm.

I thought it was 3 pulses on the upper plug per revolution and 6 pulses on the lower plug per revolition (3 full cycles per crank rotation).

I'm going to look at wiring diagrams on Sat and get some of the cluster wiring locked down for the tach cluster wire.

try the rx7club.com I'm sure plenty of 7 owners have used tacks on their FD's

Originally posted by JCC
I think the 2 rotor wankel has the same ignition pulse frequency as a 4 cyl so if the shift light uses the tach signal it will work. The tech support dept. of the unit's manufacturer should be able to help. An electronics geek could also design a light to go on with the red line warning tone but it would not be adjustable for rpm.

http://www.autospeed.com used to have the core elelctronics for htis.... just a light or tone that you can adjust the level for.

It would indeed hook up to the cluster feed for the tach.

Originally posted by syntrix
I thought it was 3 pulses on the upper plug per revolution and 6 pulses on the lower plug per revolition (3 full cycles per crank rotation).


Doesn't the crank rotate 3 times for each rotor revolution, so there's basically one cycle per revolution for one rotor? There are 2 spark plugs per chamber, 2 chambers, so wouldn't that come out to 4 sparks per revolution total? I don't know how the timing of the 2 plugs in each chamber is setup though.

I'm guessing a 4 cyl would put out 2 sparks per revolution, a 6 cyl 3 sparks, etc.

I don't know exactly how a tachometer reads the timing, I'm just wondering if this information is correct for my own educational purposes.

Originally posted by mp5
Doesn't the crank rotate 3 times for each rotor revolution, so there's basically one cycle per revolution for one rotor? There are 2 spark plugs per chamber, 2 chambers, so wouldn't that come out to 4 sparks per revolution total? I don't know how the timing of the 2 plugs in each chamber is setup though.

I'm guessing a 4 cyl would put out 2 sparks per revolution, a 6 cyl 3 sparks, etc.

I don't know exactly how a tachometer reads the timing, I'm just wondering if this information is correct for my own educational purposes.

You have it right or my thinking agrees with yours :) A 4 fires 2 cylinders per crank rev with no torque overlap. The wankel fires a rotor face from each housing per output rev due to the internal gearing. Each rotor is rotating 180 degrees from each other for balance. The neat thing is the torque does overlap due to the 270 degree combustion cycle so the torque is like a 6 cylinder engine. I've left out the second sparkplug per rotor as it fire so close in time to the first one. The tach probably reads either the leading or trailing spark system but not both. From what I read, the trailing plug does most of the work as the flame front is rotated forward with the rotor.