Datalogging?

[aaronc7]

Thank you for the heads up on the headers and speed. I have an obdlink mx so it should be affected this way.

I usually look at the gps and throttle to see what I could have done better, in particular if I try different lines.

Then I am trying to figure out what to log on slow channels as debug / backup for the car. It slowed down on me once and I am speculating transmission got too hot. So I thought having the temp ranges for DSG, engine, coolant would be beneficial afterwards. But I guess if it affects the throttle resolution from the fast channel then I would have to be careful about it.

Any suggestions on other possible PIDs to log ?

Transmission temp:

Header: 0x7E1
PID: 0x 22 21 04

Looks like a 2 byte response. Not sure on the equation but mine was in the low 100s (F) and the response was "27 00". Seems to be a different EQ than oil temp.

You could probably put "trans temp" on the "slow" logging list and it shouldn't have a big impact on the overall rate. I believe the slow channel list is only polled once every 10 cycles..

I can't think of really anything else useful for track stuff. I'd probably throw IAT in the slow channel list too.

 

[spaparizos]

Transmission temp:

Header: 0x7E1
PID: 0x 22 21 04

Looks like a 2 byte response. Not sure on the equation but mine was in the low 100s (F) and the response was "27 00". Seems to be a different EQ than oil temp.

You could probably put "trans temp" on the "slow" logging list and it shouldn't have a big impact on the overall rate. I believe the slow channel list is only polled once every 10 cycles..

I can't think of really anything else useful for track stuff. I'd probably throw IAT in the slow channel list too.

Turns out it was simple, just number no equation.
So for racechrono:
Header: 0x7E1
PID: 0x 22 21 04
BytesToUint(raw, 1, 1)

It gets the transmission fluid temperature in celsius, same as what obd eleven reports.

The engine oil temperature also worked with :
(BytesToUint(raw, 1, 2) -2731.0)/10.0

Strange though that dashboard does not match obdeleven on this.

 

[aaronc7]

Turns out it was simple, just number no equation.
So for racechrono:
Header: 0x7E1
PID: 0x 22 21 04
BytesToUint(raw, 1, 1)

It gets the transmission fluid temperature in celsius, same as what obd eleven reports.

The engine oil temperature also worked with :
(BytesToUint(raw, 1, 2) -2731.0)/10.0

Strange though that dashboard does not match obdeleven on this.

How far off are they?

There are 2 oil temps reported by the ECU. As I understand it, one is raw sensor value and the other is a slightly filtered/averaged value. It would seem the filtered/averaged value is used on the dash, at least on my car (2017 Audi S3). Largest delta during during warmup, but once temp is reached they are more or less identical.

 

[spaparizos]

About 5C off. Dashboard was lower. And I was during warmup also.

The one I got on racechrono is the same as obd11. But you are right there is another one there.

I plan to log / check next time I am on track and see if they are off from the dashboard.