Porsche and racechrono

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Re: Porsche and racechrono

#11 Post by tedaf » Sat Jul 20, 2019 2:57 pm

KenJ wrote:
Thu Jul 18, 2019 5:51 pm
This is submitted respectfully... I know things have opened up with some AXs these past seasons, so, it's really best not to show the speedometer on your videos..... especially this last one. We won't have Alameda much longer, but let's not give them reason to curtail things early.

Have fun,

Totally fair point, and I wondered about this myself. I can update the overlay to not include speed in the videos I post.

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Re: Porsche and racechrono

#12 Post by DerekB » Mon Jul 22, 2019 6:48 pm

i had fun playing with the app this weekend and learned a bit. so far i am happy with the results just using the GPS. i did just get the the MX+ OBDLink today and that should help with accurate throttle input and speed data but the acceleration data from the GPS is great by itself.

you do need to create a new course with the GPS in hand. your phone GPS is not good enough to create the course and have it work accurately. last week when i got the course from Himanshu but was using my phone with no external GPS it did not recognize the finish some times. the app does not automatically create zones for split times so you have to create those during the course walk and 5 splits works out great on my iPad. the zones are nice to have because you can quickly see the green or red sectors in the main screen and it uses the zones to give you your theoretical best time.

i was able to sync the video from my generic action cam and i think it works well. the overlays are not as useful as using the analysis screen so i made a screen capture video of the analysis using speed delta, time delta and longitudinal acceleration. the app continues to have a problem graphing the time delta but it does show the value on the bottom of the screen. the video came out a bit choppy but it is still useful to compare my two fastest runs. i am using my first generation iPad air and i assume a newer model would fix the issue.

Himanshu has said that he doesn't want to share data/video publicly preferring to use email. i do think that is the best way to go for Alameda, i don't think there is an issue posting speed data at marina but if it is a problem i can take the video down, make it private and only share it using the email chain we have.

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Re: Porsche and racechrono

#13 Post by mikey » Mon Jul 22, 2019 9:49 pm

Don't worry about it. This is a private forum anyway so feel free to post.
There is another racecar in my future

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Re: Porsche and racechrono

#14 Post by hpatel » Sat Jul 27, 2019 10:01 pm

Thanks Derek for getting the communication started and thanks Mike for having this forum available for us to post.

My fastest lap at the last LPR event can be viewed at - https://1drv.ms/v/s!AvpsCl-IH8Bth8VvjszaYtQWWEz-5Q.

Note, the lag described by Teddy for throttle response in previous videos is gone in this video. That is because I replaced the Throttle Position sensor with Accelerator Position sensor in Edit Overlay menu. For everyone's sake, I use Kiwi 3 for OBDII data, but do recommend getting MX+ for the new buyers. Derek, it would be great to see if throttle response data is collected by the high speed channel with MX+.

One more piece of information. Accelerometer in iPhone is quite sensitive. It should work as well as the sensor Teddy and I have within our GPS unit. Make sure to secure your phone while driving to get good G-force data.

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Re: Porsche and racechrono

#15 Post by DerekB » Sat Jul 27, 2019 11:43 pm

i got the email and was able to import into racechrono with no problem. we had quite different lines in the first half of the course but similar after that. i will have to do a deep dive into accelerometer data to see where i can improve. you definitely got a good start and the tighter line paid off. great job :)

the accelerator data does look much better than the throttle but still not quite right. it never goes above %92 or bellow %15? i look forward to using the MX+ that i got and you recommended to compare our throttle input but the accelerometer data looks good and i can learn a lot from that. i was worried about the Dual GPS not having a built in accelerometer but doing research it turns out that racechrono does not use the one built in to the Vbox or the iPhone.
"The lateral and linear acceleration is calculated from GPS only. You can also enable the real accelerometer from expert settings but that is not calibrated nor rotated."
the data i got from the Dual unit looks just as good as what you are getting from the Vbox. i am curious to see if using expert mode and calibrating it would get you better results. it would probably be able to record both and you could compare the two?

i'm not sure how useful the software would be if we are not using the same map. going forward, i think we should start a new email for each event and post the map there. Teddy said he wouldn't be at the next event and Himanshu is usually busy setting up the trailer. i will try to walk the course ASAP but working the gate could slow me down. i'm sure we will figure it out but i think email would work better than meeting up and doing Air drop.

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