Jaynen
Jaynen Reader
9/3/12 2:08 p.m.

I'd like to use one of these for my next autocross. If anyone has used them before which mounts are they using to secure their phone so they can also capture video. I plan to also use my gopro

ProDarwin
ProDarwin SuperDork
9/3/12 2:23 p.m.

Panavise Suction Mount: http://www.amazon.com/Panavise-809-Camera-Window-Suction-Cup/dp/B000246ST6/ref=sr_1_1?ie=UTF8&qid=1346700009&sr=8-1&keywords=panavise+suction+cup+camera+mount

+

snap Mount for iPhone: http://snapmountforiphone.com/

VWguyBruce
VWguyBruce HalfDork
12/23/12 12:01 p.m.

I'm looking at buying Harry's Lap Timer Pro. I already have this Bluetooth OBD II Adapter. I'll hopefully be seeing this Dual Bluetooth GPS Puck for Christmas to use with my chart plotter app. . I was looking for a OBD II App anyway and Harry's has it embedded.

Is anyone using Harry's App here on the boards? Reviews online seem favorable but I know you guys would be honest in your assessment.

sachilles
sachilles SuperDork
12/23/12 12:11 p.m.

The key with any of those smartphone based apps is adding an external gps that can sample at 5hz or better. Otherwise the phones internal gps tends to not have much detail. They are usually 1hz which means you get one data point per second. 5hz will get you five per second. An external gps also allows for better reception as you can place it in better view of the sky. Using the internal gps also sucks up a lot of battery power. Make sure to have a way to safely keep power to your device.

MattGent
MattGent New Reader
12/23/12 2:26 p.m.

Snapmount for iPhone, plus a 3" long X 1.25 X .125 piece of aluminum slat with a 1/4 hole in it. The slat is attached with double-sided foam tape to the top surface of the tray under the radio on the miata, and stays there permanently. I can snap a pic of it.

I now use GoPro for video, when I was using the iPhone for video I used the TomTom mount that Harry suggests. It works pretty well, video here http://youtu.be/6Oh6Luu1i7o .

I may be willing to sell it if that's what you're looking for. It has an external antenna and power supply.

sevenracer
sevenracer Reader
12/23/12 2:28 p.m.

I bought the Harry's app for a recent track day. Just used the internal gps.

I'd agree that you need an external gps to get good g force data, especially for Autox. But it works fine for lap times and segment times with the internal gps on a road course.

It's pretty easy to use and the auto start worked very well. It will render the video with data overlays right on the phone. Took about 5 minutes to render a 2 minute lap.

You should plan for external power, because it drains your battery quickly.

The one thing I found irritating is that it captures and renders each lap individually, and it wasn't obvious how to string them together. maybe not an issue for AX.

Same issue applies for data analysis in the App - It has standard stuff it tells you about each lap, but no obvious way to compare laps, etc. You can export the data, so I am sure you can find some Software to analyze on a PC in detail, but I didn't bother (yet).

So overall, for tracking times and getting video easily, it's good. Didn't seem to be great for detailed analysis on the phone. Maybe that's asking too much or maybe I just got bored with it before I found those features since I didn't mess with it after I left the track.

Also, not related to Harry's, I am pretty leery of windshield mounts. A guy at the track day had a go pro or something with a windshield mount, and it fell off more than once on track, and one time ended up down under his feet and pedals.

Karacticus
Karacticus GRM+ Memberand New Reader
12/23/12 8:05 p.m.

I'm using a RAM windshield mount with no trouble in my car, mounted lower left corner of the windshield, along with the Emprum GPS dongle. I did need to make sure I don't use a portion of the windshield with too much curvature. The particular mount I'm using isn't suitable for using the iPhone video-- I'm using the gopro for that.

Other notes on Harry's--

You can use the charting function to compare any lap with a selected reference lap

It's not really to do with Harry's, but the update rate from OBD port on the car is only about 1.3-1.5 Hz, which is a little disappointing. Appears to be a known issue with BMWs of my vintage though.

Karacticus
Karacticus GRM+ Memberand New Reader
12/23/12 8:15 p.m.

Mid-Ohio

This is one of my first attempts at doing overlay of the video from the gopro. Exact sync is still a challenge as you can see at the end of the lap, and you can also see the effects of the slow update rate on the OBD.

ProDarwin
ProDarwin SuperDork
12/23/12 8:51 p.m.
VWguyBruce wrote: Is anyone using Harry's App here on the boards? Reviews online seem favorable but I know you guys would be honest in your assessment.

I have the Dual BT puck with mine.

Its a great app, but a pain in some ways. Calibrating the accelerometers is a tremendous pain in the ass. Good luck finding a flat straight road you can drive on for long enough to get them to calibrate.

You also need to manually mark the start and finish... these work well, but I've often had a lot of trouble getting the start to auto-trigger the recording at the correct time.

I'm hoping to play with it a little more in 2013 and perfect it.

Karacticus
Karacticus GRM+ Memberand New Reader
12/23/12 9:07 p.m.

In reply to ProDarwin:

Since some of the latest updates, (I'm currently at v16 and change) I've found the calibration to have turned into a non-issue. It just seems to take care of itself on the drive from the paddock to the grid.

It's definitely not without a learning curve though, especially with regard to getting up and running reliably with your selected sensor suite.

ultraclyde
ultraclyde Dork
12/23/12 9:21 p.m.

I was just talking with a friend today who uses Harry's, and he was telling me it only records time every three seconds, so his Roebling laps could have been 1:21 instead of 1:24. I've never used it so I cant comment on wether or not that's true.

MattGent
MattGent New Reader
12/24/12 5:17 a.m.
ultraclyde wrote: I was just talking with a friend today who uses Harry's, and he was telling me it only records time every three seconds, so his Roebling laps could have been 1:21 instead of 1:24. I've never used it so I cant comment on wether or not that's true.

This is not correct. Regardless of the GPS record rate (which is a function of the antenna you are using), it will extrapolate between the two points either side of start/finish to give a reasonably accurate lap time.

car39
car39 HalfDork
12/24/12 9:14 a.m.

You can have an issue at autox if the finish is close to a loop in the course. I couldn't get data one day because the first turn went by the finish at a 90 degree angle (one car on course at a time) and the system read that as the finish. They would't give me FTD for my 6 second run either

Karacticus
Karacticus GRM+ Memberand New Reader
12/24/12 10:31 a.m.

I know that there's been updates made to the road course definitions that now define the direction of travel at the start finish line, which helps at certain courses where the start finish ine is close to another loop in the course.

What I don't know is if similar changes have been made for auto-x. I do know that you can/should go into the set up info to change the settings menu and change the POI detection to narrow for this kind of situation.

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