Neel's Hayabusa experience also proved handy, since he only needed to open his laptop and call up the list of ECU pin locations for our year Hayabusa ECU. Wiring everything to the ECU-side of the wires is much cleaner and simpler than chasing data all over the harness.
When Neel taps into a harness, this is how he likes to splice things. Do everything in a single crimp, heat shrink it, then fold it over and strain relief it to the rest of the harness. Since he's wired a few hundred more race cars than I have, I'm gonna say this is probably a good way to do it.
We made a clean, 6-wire jumper harness to carry data from the ECU connector
Since we couldn't find a completely reliable calibration curve for the coolant temp sensor, we made our own. Our first attempt involved boiling water in the microwave, pouring it in this beaker, and submerging both the sensor and a thermocouple in it. As the water cooled, we would record sensor voltage and corresponding temperature every few degrees and enter that data into the AQ-1. The curve turned out to be very non-linear though, and since boiling water only ever gets to 212F (and cools significantly on the way from the microwave), we couldn't generate a curve we were confident in.
To cover the higher temperatures, we switched to vegetable oil and a hot plate. There are some subtle tricks to collecting data this way. First, the big coolant temp sensor changes temperature much more slowly than the small thermocouple, so you should heat the oil to peak temperature, wait for both readings to stabilize, then record data as the oil slowly cools. The slow change will help ensure both sensors are reading the same.
At the same time, there can be hot and cool spots in the oil bath. Minimize these differences by zip tying the two sensors together, and continually stirring the oil. Yes, this is tedious…