Da Groj

All you need is a couple of gages to fit in the ashtray direct from sending unit to them. Should be pretty cheap Whitney, Summitracing, Jegs has a set of American Muscle Gages from Autometer 2 1/16" Page 54-55 in current catalog or look on line. About $100 for both w/all fittings/instructions. At least you are a Geek. That is very important. I am not. I have a nearly new billet radiator cap with temp gage that is accurate/fits for an old Foxbody but you have to lift the hood to see it:) I used it and a heat sensor gun to learn what was "normal" for the factory gage. Don't rush yourself. Most guys tow cars under construction to events for good reason. Temp and Oil pressure are pretty critical. Loren and several wrencher/geek guys here will eventually chime in to help with this once they get interested in it or fully understand what you are trying to accomplish.

If you're running any modern factory ECU with OBD2, you should be able to get one of THESE (or similar). With that, you can use the Torque app (or similar) on your phone (or a tablet) to view any data that is available in the ECU.

Oh, and the speedo usually operates from a speed sensor in the transmission. Where the speedo cable used to come out, now there's a magnetic speed sensor. I'm not sure how Mazda configured the RX-8, though. The speedo signal could process through the ECU, or it could go directly to the dashboard. If you've got an RX-8 wiring diagram, you should be able to find the answer to that question. Then the next question is whether the output of the sensor in your GM transmission is compatible. (it very likely is, it's a pretty basic thing)

Thanks Loren. It's been a hectic these last few weeks. I haven't had time to dig through my RX8 diagrams but I'm pretty sure the entire dash is Canbus. The GM speed signal comes out of the PCM. I finally got my windows tablet working with HPTuners though so I've now got gauges. However, my suction cup mount slides around if you take a corner at any speed. Next up is a BT ODB2 adapter to open up my usb port on the tablet for charging. The car seems stable though. Engine temps are well within limits and that was always my biggest fear.

I've been looking at the next two events you guys have and I'm trying to determine if I can make one of them.