24Chromium

Anyone using this iPhone application? I couldn't resist for $15. For another $100, I purchased the TomTom windshield mount that has a GPS antenna internal (supposedly better than the iPhone's internal GPS).

I'm anxious to test it out soon.

Malakas

It's a great app! It worked well on my old 3G iPhone, and expect it to be even better with the faster processor of the IPhone 4. I found it suffered a little bit on faster tracks, like Texas World Speedway - the gps (or phone CPU) could just not keep up with speed of the car, lagging behind and sometimes skipping over the start/finish trigger marker... Like I said, I hope the new phone and it's faster CPU will cure that.

The newest version even has video - and I hear the next update will include overlays. With the Tom Tom gps antennae - it will be a great setup. I mean, it's no Traqmate. But considering the cost... It's a cool piece of kit!

ex10psi

for those of us who use android phones... i've been using this app called trackmaster: http://trackmaster.trackaroo.com/web/trackmaster

i believe i paid around 6 or 7 bucks... tested against someone using traqmate and it was spot on. couldnt believe the accuracy and all the features!

ok, back on topic... sorry about that

TRAKCAR

Have you tried overlaying the data with video?

James A

I have found Lap Timer works very well, including TWS, but you MUST have a good signal and that depends on where you mount it. There are signal strength bars on the Ap, make sure you mount it where you get good signal.
I have used it at TWS, MSR-Houston, and Grandsport Speedway and have had good luck with it. A friend ran TrackMate at an MSR and Grandsport event and we correlated very well on times.

Malakas

Where / how do you mount yours?

24Chromium

O.K., back from a couple of track days with Harry's Lap Timer Pro for the iPhone. $15 on the App Store. I was about to invest 100x that amount on a pro system, till I stumbled on this find. But, with the addition of a $100 TomTom cradle, I get 2x the accuracy of the iPhone's internal GPS, plus a place to mount it. The app uses all the phones capabilities and is dirt simple to use. I get a video for each lap as well as lap times, fastest speed, average speed, G forces and lineal forces all around the track, all displayed on an accurate track map! It's freaking awesome! Granted, it's not up to the accuracy or reliability of a pro system, but it more than met my expectation for a lowly $115 investment. The author claims the lap times are accurate within 6 tenths of a second.

I did have trouble understanding the whole picture of use as well as the nuts and bolts. Documentation is not very helpful for the first timer. In 3 sessions at the track, I only managed to record a video of one entire session. Then I discovered that my GPS was not showing a signal - at all! I had mounted the cradle so the phone was a couple of inches up off the dash and maybe 6 inches to the right of the windshield center. I tested various spots for signal strength and ended up moving it near the top of the windshield and tucked to the right of the mirror. It did make it useless during driving, but I didn't really care at this point. I also had to start it before I belted in, since I wasn't able to reach it with my 6 point harness on. Gloves don't help either with a touch screen!

The other troubles I had were that I needed to tell it I was at a specific track. They have pre-defined tracks available for download. That seemed to be the key problem on getting it to record lap times. Then once I had it recording properly, the other issue I had was understanding how to access the data. Apple makes it so simple at times, that sometimes it makes it harder to understand. To see my speeds and Gs at various points on the track, I needed to zoom in on the track map (standard iPhone pinch gestures).

All in all, it worked pretty damn well for $115 investment! However, I do plan to buy a real camera and mount in on my roll bar. With it mounted the way it is now on the windshield, I can't see the entire front of my car, nor can I see myself or my hands on the wheel (great learning tool!). But for lap times, I'm pretty darn happy. It didn't record every single lap accurately, but hey, you get a _lot_ for what little you pay. Big thumbs up.

zanwar

As a laptimer it's fairly accurate, within a few tenths of my transponder. It has some trouble communicating with the TomTom cradle. I've found it's best if you leave the app, dock the phone, then switch back to the app. With the cradle mounted near the front of the windscreen it picked up a decent signal. I tried using the video feature but the app reported some kind of error and I didn't want to cut my session short to fix it. The built in graphs for speed/distance analysis are an excellent feature. The iPad version of the app is just for analysis on a bigger screen, it's worth the extra cash. Traqmate is a more accurate and capable tool, but you could go a long way with just this program. If the video works properly the next time I'm at the track, I might stop bothering with my Traqmate/GoPro combination.

zanwar

Here's an example of the track map it produces

James A

To mount the iPhone I bought a holder that snaps into the AC vents on the dash, works pretty darn well. Snaps in, but takes a little work to get it out.

ir_fuel

I wonder how precise it is in the corners. I never tested with a TomTom GPS antenna (didnt exist at that time) but I did some tests myself with an iPhone 3G + gps (I wanted to write my own laptimer), plotting the recorded positions of the GPS unit. As soon as you started cornering the coordinates went all over the place, to settle again as when you got on a straight. It also only got a GPS sample every second or so, way too low for decent trajectory analysis.
I have no idea what frequency the TomTom antenna gives you, I hope it is more. On the straight it could get away with interpolation to get you the laptime, but trajectories with the standard GPS unit will be far from accurate I think.

To give you an idea, the RaceLogic system works at 10Hz, hence the need for the external antenna as the receiver is much more sensitive.

Then again, for what you paid it really is a bargain.

ir_fuel

Just checked their site a bit and it is a cool piece of kit, but for analysis on the racetrack during an event if you don't have the hardware the price difference with "real" stuff isn't that big in the end.

(I give EU prices as I don't know the US ones).
A Performancebox costs 400€
A netbook costs about 250€
total: 650€
(that is what I am currently using as setup)

Let's say you already have an iPhone, so cost 0
iPad, cost: 600€
Software, cost: 12€ * 2
total: 624€

The big difference here being that you lack video recording in the first scenario, but have more accuracy in the recorded data.

If only I could easily sync my GoPro movies to my Performancebox data .... hmm, feel a software project coming up

my911rs

I have been using Harry's lap timer for a while and it works great. NOTE: The TomTom kit does not work with IPhone 4. It will not charge it or provide any GPS benefits, but the phone will fit in the cradle, and it is a good cradle at that.
The Iphone 4 seemed to have worked very well at VIR and Roebling even without the TomoTom assist. What is key is to ensure that the app's Start / finish point is located exactly on the track. This can be easily achieved by overlaying the Google image and dragging the flag to the desired location.

Blaine S

Actually there is a real easy fix to make the iPhone 4 compatible with the TomTom cradle. There is a small spacer you install on the cradle which puts a bit of pressure on the back of the iPhone 4 so that it makes proper contact. TomTom is giving them away free or you can use a small 1" x 1/2" adhesive backed felt from the hardware store. The thicker felt is what I used (about 1/8" thick). PM me if you need more details.

24Chromium

Yeah, I should have mentioned in my original post, that I am using an iPhone 4. The TomTom cradle I purchased did not come with the "spacer" for the new phone, but I simply added a couple of small diameter 1/8" thick felt discs to get the same effect. It does charge the phone and I'm assuming from my results that it also uses the GPS of the cradle.