For Autocross: Vbox Sport + BT1 or Vbox Sport + GL1 ?

[Metalgearsolid_x]

Hey guys,
I have been searching, browsing and watching this forum for a while. I am a occasional track driver (2-3 HPDE events per year) that have focused his attention to autox this year. I am so hooked on autox, I want to do (been doing) 2-3 sessions per month.

I have been eyeing out harry's lap timer for a while. I think it's one fantastic software. Thank you harry for giving us such awesome product for barely any $$.

Now the most important questions. I have been reading and I found out that GPS upgrade is mandatory for autocross because everything is happening soo fast. So instead of the cheaper stuff, I want to buy the Vbox sport as it has the 20 hz refresh rate. This should be perfect for autox. Now I was looking into OBD to add on to this. I was leaning toward Go point GL1 because it doesn't use bluetooth (it's wired) and since it's wired, there's no lag in data? what's your input? My other option will be BT1 but Harry said not to overload bt frequencies.

Thank you for you help

[Harry]

For GPS, you consider the upcoming XGPS160 too. It will feature 10 Hz - which is most probably good enough even for AX. On BT / wiring: every sensor has a lag between the event itself, and the time it arrives in LapTimer. But this lag has an impact for realtime viewing of data only. Any recording will add the offset thus correcting the lags (it can be fine tuned). On the other hand, if you have an iPhone4 / 4S (connector topic), you may indeed opt for the GL1 to have the BT bandwidth available for VBOX / XGPS.

- Harry

[Metalgearsolid_x]

For GPS, you consider the upcoming XGPS160 too. It will feature 10 Hz - which is most probably good enough even for AX. On BT / wiring: every sensor has a lag between the event itself, and the time it arrives in LapTimer. But this lag has an impact for realtime viewing of data only. Any recording will add the offset thus correcting the lags (it can be fine tuned). On the other hand, if you have an iPhone4 / 4S (connector topic), you may indeed opt for the GL1 to have the BT bandwidth available for VBOX / XGPS.

- Harry

Thank you Harry. I appreciate your reply. It's funny you mention the xgps160 because 10 minutes later I submitted the thread, I was like, "I should have asked about the new Dual 160 too! "

I think it has everything I'm looking for. I'm NOT a race car driver. I do 2-3 HPDE track and regular autox. As long as 10 hz rate is good for autox, I think I'm gonna give it a try. I'll place an order tomm morning.

I do have Iphone 4s. If anything, I may upgrade to iphone 5 sometime this year or next year. So, do you think I will be able to use GL1 with the iphone 5 (due to different connector and all) or should I just get the Go point BT1?

Do you recommend me running GO POINT BT1 and xgps160? I'm curious to hear your recommendation. I know if anyone can guide me to the right direction is you

Thanks for your time Harry.

[Harry]

Can't say yet (have not received my test device yet). It might get tight with the 160 plus another BT device. The 160 works with standard NMEA sentences, which means it will require double the bandwidth the 150 does... The GL1 will require you to use an adapter with the iPh5, which should work. Maybe you drop GoPoint a note?

Harry

[Metalgearsolid_x]

Thank you for your prompt reply Harry.

So I did get the XGPS160 and GL1 to keep the bluetooth load low. (I think you need to add the XGPS160 next update because now it's recognized as xgps150 BUT it does show 10 hz rate )

I tested out in various config: GPS only with GO PRO overlay. GPS + GL1 with go pro overlay. GPS + GL1 with iphone HD recording. here's my finding:

XGPS with GO PRO HD Hero overlay (go pro 2 )
Works pretty well. Very accurate. probably my favorite but not having rpm and throttle data makes me want the obd connected too.
[youtube]http://www.youtube.com/watch?v=Z71km_veCSs[/youtube]


I also did recording with xgps and gl1 with iphone video. I thought since it's all in 1 device, it will be the most accurate. Well I was disappointed . It's even worse (especially the OBD). I overlayed using overlay button

[youtube]http://www.youtube.com/watch?v=Nf1g03gPGQA[/youtube]

Can you tell me Harry's what I'm doing wrong with the OBD Gl1? is it bc obd taking over against xgps, hence I'm getting sloppy data once gps is connected?

[Harry]

The OBD data seems to be ahead of the video and or GPS information. The GL1 is a pretty special device as due to it's cable connection it has very low latency (and pretty high update rates). When LapTimer mixes sensor data, it needs to make a guess how old the data is it receives. Any sensor has a certain delay between the real world event, and the time the corresponding data is available for LapTimer. While GPS has a pretty big lag, OBD is lower - for the GL1 in particular. LapTimer has a Expert Settings for all sensors. The standard value of 1 s is obviously too big for the GL1. So please try reducing it to 0.5 and go through a recording / overlay cycle again (delays are applied to new recordings only, not to existing data).

There is a similar thing for sensor data to video data delays. The video sensor has a delay too and can be adjusted (in RR you do this manually for each overlay). Please once you have OBD and GPS well synchronized, please check the sensor / video alignment. It can be adjusted using another Expert Setting named "Overlay Synchronization". In case sensors are ahead of video / audio, increase the video overlay sync value. Once this has been done once for your BT1 / GL1 / LT video combination, it will be fine forever

- Harry

P.S. It seems RR still has no interpolation implemented - the engine rpm dashboard moves pretty "un-smooth".

[Metalgearsolid_x]

Hi Harry,
So I went to my first autox with GL1 and XGPS160 setup. XGPS worked fine but the OBD was troublesome. However, I made a mistake. I know you wanted me to bring the OBD delay value to .5 from 1s. I "thought" I did that but in reality I didn't . So this video WAS shot with 1s delay on OBD. But there were other issues that I want you to see:

[youtube]http://www.youtube.com/watch?v=iELEOF1k7bU[/youtube]
Video shot with GoPROHD 2 and HLT (GP edition) + Xgps160 + Go Point GL1 overlayed with Racerender 2 (trial)

a. Why does my G-meter is so slow or doesn't move heavily with vehicle momentum/braking.

b. Why does my gears go from 1-2 and then drop back to 1 (toward the end last 10 sec or so). I def was driving 2nd gear.

c. why did the RPM buried toward the end?

d. how come I never get brake red on screen?

I have changed OBD delay to .5 now. Next event on 24th. I'll test it out. It should be better.


===================================================================================================

As for video overlay with videos shot with iphone camera, I think your suggestion worked MUCH better than first post. I dropped it down to .5 second on video overlay synchronization. Take a look:

http://youtu.be/uXeoj7Vrh1c
Xgps160 + OBD GL1

Anything else I can fine tune? (.4 or .6 on overlay synchronization or you're happy? Still, would like to see brake red when I brake.


Also, one last question, How do I start recording without being at track or autox event? Let say I want to record from my home to work. I want to use go pro HD and use harry's laptimer to create a (or multiple) run (s). Where do I go? If I can record randomly driving, I can fine tune or test out more things etc. Please let me know. I'm asking for recording without using iphone camera. Just random recording with gopro and hlt. Later I can overlay with racerender.

[Harry]

Hi,

Actually I do not want to comment on the Racerender overlay. Other than TrackVision and Dashware I have never tested the integration with it - and there seem to be quite some issues. One thing I can do is have a look into the LapTimer data used for this video to verify data is o.k. So if you want, expert this exact lap to .hlptrl and .csv and send it to Harry@gps-laptimer.de Most other things are most probably due to wrong mapping of LapTimer data to RR - which I kindly ask you to address there. Brake status is not available from standard OBD, so please check negative longitudinal acceleration as an approximation for braking.

LapTimer supports manual recording both with and without video. To enable that feature, goto LapTimer Settings and turn on "Manual Timing". This will give you "Go" buttons both in timer and video views.

- Harry

[chknhawk]

I am using the gl cable with adapter on my iPhone 5 and using internal gps. Mine seems to be working very well. I would upload a video but I'm on my mobile. Here is a YouTube link. Tell me what u think.
[youtube]http://www.youtube.com/watch?v=qnkrPrQB1yU[/youtube]

[Metalgearsolid_x]

Hi,

Actually I do not want to comment on the Racerender overlay. Other than TrackVision and Dashware I have never tested the integration with it - and there seem to be quite some issues. One thing I can do is have a look into the LapTimer data used for this video to verify data is o.k. So if you want, expert this exact lap to .hlptrl and .csv and send it to Harry@gps-laptimer.de Most other things are most probably due to wrong mapping of LapTimer data to RR - which I kindly ask you to address there. Brake status is not available from standard OBD, so please check negative longitudinal acceleration as an approximation for braking.

LapTimer supports manual recording both with and without video. To enable that feature, goto LapTimer Settings and turn on "Manual Timing". This will give you "Go" buttons both in timer and video views.

- Harry

I looked at trackvision, it's expansive $200. I like Dashware but software is too complicated compare to Racerender. I will give Dashware another try (on my day off) as you recommend that software.

I sent you the laptimer data. Did you get it?

I will let racerender know. I'll do more testing on Monday.

Thanks ) that manual timing works! that feature should be turned on as default.

I have a question Harry, this is the autocross track outlay. It starts on the left and goes to the right. I wish I could see the run/track on this map. Is there a way I can do that? lol I know our autox air strip is pretty crazy! surrounded by water. If you mess up, you'll end up in water! lol