Harry's GPS Suite Forum

Using standard ELM requests, the number of requests and the raw rate will be 1:1. ELM is a synchronous request / reply pattern which means both ends are waiting most of the time. The reason the # of requests is below the raw rate for you is that parallel request are enabled.

You can find an in depth discussion on performance optimization utilized in LapTimer on http://www.gps-laptimer.de/documentation. See the Engine Data and Developer Program document in particular. Skipping PIDs is described in this document too, but does not make too much sense. LapTimer request only relevant PIDs and does this using different frequencies. Temperatures for example are pulled at a far lower frequency than rpm or speed. Due to this, skipping e.g. one of the temperature values, will not improved the overall rate a lot.

The settings working best for your car are trial and error and cannot be answered from remote. And I do not have car specific parameter sets either. So please check the document and try the levers described.

- Harry

I'm still try and error to make it better.
But the RPM gauge is still laggy. While using RaceChrono, the RPM display is smoothly. No idea what to test further more with Harry's so far. Appreciate for any suggestion.

To which display of RPM do you reference? Video overlay or real time display in Engine View?

Harry

The overlay on the video
RaceChrono CSV with RaceRender
https://youtu.be/l0HjMz0OMVE

Laptimer
https://youtu.be/RKsuf2QNIWo

I exported the CSV from both RaceChrono and Laptimer for RaceRender3.

The RaceRender 3 RPM overlay goes pretty well as you can see from the clip with RC CSV data. But the Laptimer CSV has lag in RaceRender 3 still.

So i’d day it might be the problem while collecting data. I’m thinking if the cause from the iPhone or the Laptimer source code. The Laptimer does much more calculation than RaceChrono during fly.

Regards / Hugo

I think this is the known problem with data fusion for certain GPS / OBD update rate combinations. Some user face so called “steps” in OBD data when fused with a GPS stream. It has been discussed on another thread.

Which GPS / OBD devices have you used for the recording and what has the update rate of both GPS and OBD has been? I need the original rate as shown in GPS / Engine View and Sensor List.

Harry

Hi Harry,

I have Dual XGPS160 and OBDlink MX+ now.
That’s interestingly. The OBDlink MX+ gets
I’m facing OBD data steps problem.
Without XGPS160, the OBD rate is good. When having XGPS160, the OBD data rate is not smoothly.
Should I force the Storage rate to 10Hz?

Thanks