After being in the market for a datalogger for some time, I finally took the plunge and purchased a RaceCapture Pro 3. I looked at the common setups used on cars today: AIM Solo DL, Solostorm plus GPS receiver, Motec, etc. The RCP 3 just seemed like the best bang for the buck. However there is one issue with this setup, as far as I know, no one has openly release a map of the can bus network for a 987.1
AIM Solo already has a few channels for the 987.1 mapped, and I believe Motec has 38 channels. Solostorm can only provide whatever is available via OBDII, and on pre2008 cars, there is no can bus integration in the OBDII port itself. However, none of these companies have shared this info, nor are they likely.
Having bought the datalogger without knowing this, I was on the verge of cancelling my order. But digging deeper into the practice of can bus sniffing, I think I can probably figure out how to map the data that I want or need. The goal is to map the following info: throttle position, brake pressure, steering angle, oil pressure, oil temp, and coolant temp.
The goal of this thread is to document my trials and tribulations as I move through this project. Hopefully you guys can benefits from my success or failures. If anyone has experience or advice, all of it is gladly welcomed.
Currently the RCP 3 is on order, and I am awaiting delivery. I'll post photos of the unit when it arrives.
The first step is to figure out how to data log the can bus. RC provides a simple can bus sniffer, but there is no filtering ability. Meaning you can collect all data on the network, however there are 1000s of packets to sort through. With can bus hacking on the up and up, in the last few years, there are tons of tools that are free, which have filtering capability. In essence, the tool will hide any packets that are static, only showing you those that are changing due to sensor input. This can make determining pedal input very easy. Instead of running the car with the engine on, the goal would log the can bus in accessory mode while executing a single input like throttle, brake or steering.
The first challenge when receiving this unit will figuring out how to connect the datalogger to one of these third party tools. The tools will be pivotal to making a daunting tasking into one that is easier to digest.
While things haven't gone quiet as planned, I've made some progress by using Putty and Excels data filtering tools.
The following Can Data channels have been mapped:
Throttle, RPM, Engine Temp, Oil Temp
Throttle
ID: 578 Offset: 5 Length: 1 Formula: *100/255+0
RPM
ID: 578 Offset: 3 Length: 2 Formula: *.25/1+30
Engine Temp
ID: 581 Offset: 4 Length: 1 Formula: *.75/1-48
Oil Temp
ID: 1089 Offset: 1 Length: 1 Formula: *.75/1-48
I'm not 100% sure the 987.1 has steering angle. As for oil pressure and brake pressure, I think a sender will need to be added. Should be easy enough.
Next step is to mount the datalogger, and finalize the wiring for power, ecu can wires, and GPS receiver. Then work on having the system automatically trigger the gopro for recording.
I think I've identified the packet that contains steering angle.
Still working to determine the correct offset and length, then formula to decode.
