Engine is in and fires up. Tying up loose ends right now.
Top of that list is some frustration with the Racepak stuff. Bottom line is it simply can't read any PIDs from the 2012 ECU I have. Not with the OBDII adapter cable or with the CAN hi and low hardwired directly to the dash, despite the fact we can view live data streaming via that same diagnostic connector with either a scan tool or HP Tuners. Racepak themselves have no idea why it can't read this ECU, and I've verified this particular dash will pull PIDs via the adapter cable to diagnostic connector on other cars such as an ND that was here in the shop.
SO... I'm bypassing the 'read the ECU' plan. Wired in a temp sensor for coolant and adding the Racepak GPS module for speed. RPM is the complicated one because these ECUs have no conventional tach signal output. Autometer tach signal adapter part number 9117 was the solution.
Pic here shows how it's wired in, this was just temporary crimps to verify it worked before wiring it in properly...
The signal adapter gets wired in-line with the two main +12v supply wires that go to the coils, one wire to each bank. Follow the instructions included for an LS engine but your wire color is different. Pink/black is what you're looking for in the LFX harness. Start at the coils and follow the light gauge pink/black wires up-stream until you find where they split out from a thicker gauge pink/black. That's the wire to intercept. There are two of these wires, one for each bank. The autometer box outputs a lovely +12v square wave standard tach signal. The Racepak instantly reads it. Change the Racepak to V6 Even Fire (default seems to be V8) and voila. We have RPMs.
Next up was some issues with the oil pressure readings on the Racepak. Using an ACDelco D1800C sensor which is equivalent to the factory Camaro pressure sensor but there is no scaling info available for this sensor. Since we're talking about oil pressure here, I wanted to be able to have complete confidence in the reading so I decided the best approach would be to test it personally and then manually calibrate the Racepak based on those results. So I needed to build a bench tester for the pressure sensor.
Here's what I made. Figured I'd take a little extra time to make something that could be useful in the future. NPT ports for all the common sensor sizes, two air valves so I can fill/bleed and monitor pressure without switching back and forth, portable enough that it can be placed in the engine bay so the sensor is operating on the vehicle wiring. Can be used to bench test temp sensors as well by standing it vertically, removing the end cap, filling with water and then heating the water and validating the temp with a thermometer.
With the bench tester, I confirmed it's a 0.5v-4.5v / 0-130 psi sensor. However, thanks to testing the sensor this way, I was able to calibrate the Racepack
very accurately to the specific scaling of this particular sensor. Dash reads oil pressure perfectly now.