Max speed on video = 127km/h

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seba76
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Max speed on video = 127km/h

Post by seba76 » Tue Jun 26, 2018 9:55 am

Hi,

I have strange problem, which I have no idea how to sort it out.

Maximum speed on the wideo is 127km/h where in real was 210km/h.

All is OK when speed is going up to 127km/h but when reach 127km/h - is not going up anymore. I have exported data to .cvs and there all is OK

Please see attached and help

Best Regards:
Seba
Attachments
speed3.PNG
speed3.PNG (111.61 KiB) Viewed 395 times
speed2.png
speed2.png (77.13 KiB) Viewed 395 times
speed.png
speed.png (519.9 KiB) Viewed 395 times
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Harry
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Re: Max speed on video = 127km/h

Post by Harry » Tue Jun 26, 2018 1:19 pm

Take care when discussing speed. LapTimer records both GPS and wheel speed in case an OBD adapter is connected. In the CSV file, you can see GPS speed is going beyond 127 while wheel speed is not. In case OBD data is available, LapTimer will use wheel speed for displays. To get GPS speed instead, turn off OBD gauges in Overlay Configuration during Video Export.

The reason wheel speed is not going up is probably due to some freeze in OBD data flow. This can happen in case the adapter loses connection to the smartphone. There are other reasons too.

- Harry
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seba76
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Re: Max speed on video = 127km/h

Post by seba76 » Tue Jun 26, 2018 4:27 pm

Thank you Harry for promt answer.

There is no conncection problem with OBD adapter, but it is definitly some issue with OBD.
It is not connection because it is exacly the same on all my 45 laps. And RPM is correct.
There is a lot of problems with BMW bikes and ODB.

What is better for me now ? :) Correct speed or RPM's :)

Thank you Harry
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Harry
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Re: Max speed on video = 127km/h

Post by Harry » Wed Jun 27, 2018 12:36 pm

You may try the "Force Overlay GPS Speed" Expert Setting too. ;-) It is available in the Video Tweaks section.

- Harry
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Weschurch
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Re: Max speed on video = 127km/h

Post by Weschurch » Sat Jul 28, 2018 9:27 pm

Just noticed something similar. Vehicle speedometer reported speed matches speed shown on overlaid video up to about 110 mph; after that vehicle speedometer shows a higher speed than what appears on overlaid video. Had not noticed this before as I just ran my first time at Watkins Glen in the USA, and hit 130 for the first time (back straight). Previous top speed on speedometer was 120 at a couple of other tracks; overlaid video only showed a max of 118, so just figured it was a response time thing (top speed hit just an instant before going on the brakes for the upcoming turn). Was wondering whether speed shown on overlaid video was from GPS and if there was a way to force the app to use speed from the OBD.

Also, anyway to get braking "intensity" to show similar to throttle position?

Thanks for a great product; coupled with exporting files to 3rd party tools like Circuit Tools is helping me understand what's happening on the track so much better!

Wes
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Re: Max speed on video = 127km/h

Post by Harry » Mon Jul 30, 2018 8:29 am

Hi,

Your car's dashboard speedo will always report too much. This is due to legal requirements where manufacturers need to make sure they never report less than reality. So a +5% value is expected. GPS speed is the most reliable and precise value when measuring on a straight with constant speed. As discussed quite several times here in the forum, measurements are heavily smoothed for consumer level GPSes, so short peaks are usually missed. When going at high and constant speeds, this is no issue.

The best way to get precise speeds is to compare OBD and GPS speeds on a highway and set the OBD speed multiplier in LapTimer's Expert Settings so numbers reported from GPS and OBD are the same.

With OBD available, LapTimer will always use this value for overlays and views. Exceptions:

- when driving faster than 255km/h (roughly 160mph), GPS will be used because OBD is limited at this point
- overlay uses GPS speeds in case you tick "Force Overlay GPS Speed" Expert Settings
- Analysis ‣ Realtime ‣ GPS always shows GPS speed

Greetings, Harry
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