Harry's GPS Suite Forum

gplracerx wrote:If the OBD data is 0.5 seconds ahead of the GPS data, do I decrease or increase the OBD delay?

Ahead in the chart is shifted to left or right? In case OBD speed is shifted to the right (compared to GPS), it is actually late? This means the OBD delay needs to be increased as the data requires more time from sensor to LapTimer (delay definition). And vice versa.

- Harry

As you can see in the graph I posted above, the OBD data is shifted to the left by ~0.5 seconds so I need to decrease the OBD delay.

yes, but had problems finding the colors shown in the legend

The 'lineal plus vertical' line overlaps the 'SPEED_MPH' line (GPS speed) almost perfectly. Lineal plus vertical is the vector sum of the integrated lineal acceleration corrected for the contribution of gravity due to pitch and the vertical velocity. Pitch was calculated as the arctangent of the vertical (y) and lineal speed (x) and the gravity correction was then -SIN(pitch). I used an 11 point moving average to smooth the vertical velocity calculated from the change in elevation with time.

I'm working on sending you a GPS Buddy log file.

I've sent two log files. One was with the internal GPS on my new used iPhone 4 and the other was using the XGPS160. One disadvantage of the XGPS160 is that it doesn't seem to connect automatically. The first log went out before I realized I had forgotten to connect the XGPS160.

The latest version of HLT seems to have fixed the noisy rpm and wheel speed plots.

Do you know which PID is the throttle pedal position rather than the actual throttle opening for a 2011 Mustang GT?

The throttle positions are one of mode 1 PIDs 0x47, 0x48, 0x49, 0x4a, and 0x4b. Please just check which PIDs are available for your Mustang: Sensor List -> OBD Sensor -> Details. In case you see one of the above PIDs, it is worth giving it a try. In case you do not see a specific PID, it will not work.

- Harry

PID E in the settings list appears to be pedal position. It worked much better this weekend using that PID. That can be calibrated on the line with a quick stab on the pedal.