How does the Rx-8 receive its mph/km?
 

I'm going to be taking my 8 out to the drag strip this weekend. I'm hoping I don't break anything...but I began to think...what if I did? Would I put it back together all stock, or play around with some different overdrive ratios? It would be nice to have a true highway gear like the 3rd gen Rx-7s, or the gsl-se 5th gear. I know fuel mileage would greatly increase, at the expense of 6th gear acceleration. (Is there ever realy and top gear acceleratioin in a N/A rotary? :D) I was'nt worried about fabrication. I'm pretty good friends with Rob Golden at Pineapple Racing. But what made me wonder was how the Rx-8 picked up the speed at wich the car travels? Do they use wheel speed sensors, or is it something along the lines of a electronic speedo gear? I guess I'll go pour over the factory workshop manual, and try to come to a conclusion....but if somone allready knows, feel free to throw your input in. :) Thanks, CJ

Your 6th gear is your highway gear. It is the overdrive. Your 5th gear is the 1:1 ratio that the RX-7's and most other cars (5 speeds) have in 4th gear. You just have an extra gear to play around with on your way up there.

uhhh.....I just want a taller 6th gear. I want something that at 80mph, I'm spinning the engine around 2,900-3k rpms. I was aware that the 8s 5th gear was 1 to 1. I hope I did'nt confuse anyone. CJ

OK makes more sense now. You need a 7th gear!

It uses the wheel speed sensors and the tranny speed sensor.

Wheel speed is picked up by the ABS wheel speed sensor. The ABS / DSC unit sends the speed info through the CAN line to the PCM & instrument cluster.