I bought a and Torque Pro to use with my Android phone, seems to work great with my XKR-S. I'm good with Excel data manipulation and graphing and hope to get some repeatable performance data so I can compare before and after effects of mods, and also monitor for any potential problems. I'm trying to figure out which data is useful to display, or to log. Has anyone got some sample data screens or list of OBDII or calculated values that they've found useful?

 

Some people like to track their IAT, or Intake Air Temperature.
For potential problems, I'd recommend watching the Water Temperature and Voltage more than anything else.

 

Before doing any of that, check fuel trims (at idle, hot engine, parked) are near zero.

 

The gauges I have displayed long term fuel trims, intake manifold pressure as well as engine coolant temp and battery voltage.

 

Pulled about 15 minutes of 1-second interval log; my bank 1 long term seems to stay at 4.6875 % but bank 2 fluctuates between 1.5 and 5.5 %...does this indicate a problem?

 

The only real difference is the O2's and injectors. I'd bet you have a lazy O2 sensor. Should get a code if it gets lazy enough (# of cycles rich to lean per second gets too low). That's the code my downstream O2's will pull on occasion.

 

Up to about 5 is normally OK.

The codes flag way beyond that - a bit late really which is why it's worth having a look periodically.

 

My XKRS blew all coolant after bursting a plastic part, all in a few minutes after first light came on. So watch the coolant temp, as there's no early warning indication.

 

Thanks, I'll write that up on my log and keep an eye on it.

Good to hear, thanks. I'll keep an eye on it since the other one seems to be less stable.
I've read that a code is logged when left+right value sum reaches 25%, so yeah, that's a lot of leeway.

For this very purpose I have an OBDII bluetooth scanner fitted permanently to the port via an extension cable, on which I've cut the power wire and substituted it with a fuse tap. That way the scanner is on only when the car is on, and won't keep draining the battery. On my phone, I have YouBlue set up to start Torque Pro when the scanner is detected, and Torque has an alert set at 100°C / 212°F coolant temp. This way I have essentially automatic logging & alerts whenever the car is running.

 

I've only run my XKR-S in cool weather so far and the coolant temperature seems to stay around 194-196F. When does the thermostat open? What are the highest typical operating temperatures you see?

 

For the 5.0L engine the thermostat starts to open at 190*F and is fully open at 205*F. I have seen on my Scan Gauge ranges from 193*F up to 214*F depending on the outside temp. This has usually been in outside temp of 60*F to 95*F.