Giacomo

Any recommendations on a which lap timer (must have a predictive lap time feature) is best to use in a pinch? Harry's or Lapping Coach seem to be the options I found. My iq3 has gone back to racepak for repair and I really only want something to peek at during practice and qualifying until I get it back which won't be until after the Mosport club race.

IcemanG17

Harrys works quite well for $19.99.....I did buy the "dual" outboard bluetooth GPS to go with it and it works quite well.........hard to complain for $120

DCP

Harry's works really well with an external GPS; not so well without it. Probably also true of any other timing app. I use Emprum UltiMate for better GPS.

turbochad

I use Trackpro. Like all iPhone timers it works best with a GPS enhancing base like the TomTom mount up on the top of the dash. I get times that are typically within hundredths of my transponder times.

gvtesse

harry's seems to work well. Not sure when it was added, but Harry's finally captures video for all sessions and added a min/max speed display on the overlay.

DCP

I don't think that you can get predictive lap timing and video at the same time because if you record video, it takes over the screen and you cannot get data displays.

Giacomo

How good are the lap times for Harry's without the GPS add-on? One significant digit to the right of the decimal is enough for me. I just want something that spits out a lap time and a predictive time so I have an idea what I'm turning and when to park it during qualifying, nothing else (ie, video or analysis) really matter at this point. I would prefer not to have to add the $100 GPS because the iq3 already has a GPS installed on the car but it is hard wired to the unit.

When I search the App store the only apps I can find that seem to do this are ioDigital Design's "Lap Timer Data Aquisition" $12, Harry's $20 for the Pro suite, and Lapping Coach lap timer $29. They all have some analysis functions but how visible are the lap times as you race by? The Lapping coach lap timer looks a bit simpler but I like the big number display. Could not find the Track Pro app??

turbochad

Here is Track Pro

http://www.fastlinetrackpro.com/trackpro/index.html

The on track display is good with readable live lap timer. When you cross start/ finish it holds the last lap time for a couple of seconds before returning to the live timing mode. Using a TomTom mount in the lower driver side corner of my windscreen I get VERY accurate times.

I wish it would do predictive times and gap, but I guess you can't get everything.

Chad

Exigent

I've been using Harry's Lap Timer Pro for 3-4 years and its a fun app.

How well does it work? Depends on what you want. For simple lap timing it works just fine and it does a nice job of video that is sync'd with the lap times. All of the other features are sketchy without an external GPS and it will use a lot of battery.

For $20 it's a steal considering you can move it from car to car with no headache.

aeshultz

I'm pretty sure that CMS LapTimer does predictive timing. I say that becuse I just installed it, and won't get to use it on-track until next weekend. Sold and supported by a Porsche-driving race shop, if that makes any difference to you.
I choose it over Harry's for a couple of reasons. It's on teh App store- funny that your search didn't show it.

JRMaroon

Where did you mount the Dual GPS unit? Did you test multiple locations or have good performance right out of the box?

chrenan

I tested this a couple of weeks ago at a time attack at Stratotech, a small track outside Edmonton. Timing by the transponder my best lap was 72.487 and Harry's Laptimer had that lap at 72.61 with no GPS add-on, just the iPhone 4S.

HalV

Did you compare other laps to the transponder? Was the error rate about the same (+- 0.15 s)?

Drew_K

I use Harry's Lap Timer and it's accurate as an OVERALL lap timer (individual lap times) and the video is pretty good; however, the GPS on the iPhone isn't accurate enough to get accurate instantaneous readings, so the MPH is always way off and I imagine that would also throw off any predictive lap timing. If you get an external GPS, I've been told that these problems go away.

Either way, the lap timer sucks a lot of battery power so I'd find a way to have your phone plugged in while on track.

chrenan

For each session on track we're given our best lap time recorded by the transponder. For the four sessions that night the error rate was about the same between Harry's and the transponder on my car.