rfn026

What have you found useful for the track?

Richard Newton
Car Tech Stuff

MarkDFW

Harry's lap timer is the best deal going. Get an external GPS (such as emprum) and your lap times will be accurate within hundredths of a second.

Add a mount such as iottie and you are set. You can see mine going in this video. I used my GoPro for video but you can use your phone as well with Harry's lap timer

Bad Karma

Also heard good things about Trackmaster, but I have not tried anything personally yet.

oh1vette

Harrys Lap Timer here.....

Scooter70

It depends on which phone/platform you use.

Android: Trackmaster
iPhone: Harry's Lap Timer

JSTAN

Here is a lap at Limerock using Harry's Laptimer with an Iphone 4s.

I have the phone mounted on the back of the Brey Krause harness bar using a RAM mount.

As mentioned above, get an external GPS for better accuracy.

CHJ In Virginia

Here is a video with data shot at VIR using Harrys Laptimer and IPhone 4S. App is $19.95 and well worth the $. I'm adding the OBD dongle for more throttle, and brake data prior to the next event.

NOSLO6

Another vote for LapTimer-- Harry is an awesome developer. Amazing bang-for-the-buck.

I run an external GPS antenna, but friends have recently tested it on iPhone 4/5s and found that just the phone's setup to work within 0.05 of a fancy transponder (this may vary depending on track location).

I'd always assumed it would be much worse so it may be worth trying it first before shelling out for an external GPS. The RAM mount Harry recommends on his website is incredibly beefy and well thought through.

Note MarkDFW's mounting location-- looks like he's watching split times, which is pretty cool.

JeremyGSU

The timer feature appears pretty accurate but the mph function seems to lag in watching the videos. Does the GPS receiver play a part in this or phone choice? I.e. iPhone4 vs 5.

LFZ

Just bought Harrys Lap Timer for this weekend. Good reviews and vids here.

Scooter70

It's a matter of sampling rate. The phone's GPS only samples at 1Hz, meaning that it only records position once per second. External receivers can run at 5 or 10 Hz. Think about how much things can change in one second. At 100mph, you're moving 146 feet each second. You want more data points to get finer resolution of where you are. However, there's a diminishing marginal return between 5 and 10Hz. Trackmaster recommends using 5Hz so that the phone isn't overloaded with data. I'm not sure about Harry's but I would assume the same.

MarkDFW

Correct. You can make your reference lap either your previous lap or your best lap. I was using my best lap. It was flashing red at the end of the lap indicating that was a new personal best. Harry's is hard to best for the money.

RDnomorecobra

trackmaster for droid. merge with video from a camera using RaceRender. trackmaster can be used with an external GPS to get higher refresh rate.

randomus

I would say TrackAddict if you want something a little simpler, It still gets all the data and video and overlays them immediately. When I used Harry's you had to overlay one lap at a time. TrackAddict does your whole session as long as you have enough memory in your phone. Runs on iPhone.

You can also import everything into RaceRender, the same people who write TrackAddict write RaceRender. Mine runs on Windows but I think they have a Mac version as well. This lets you import video from the phone, your GoPro on the side and back of your car, then render them all into a video really easily.

TrackAddict is great for autocross because you don't have to wait for it to render the lap, you can do an autocross run then watch it while waiting for the next run.

I have the Kiwi Wifi ODBII plug in for throttle, braking and RPM data and a bluetooth GPS.

I don't work for the company, just had better results with this than Harry's.

mrc24x

I'm happy with the CMS Lap Timer but I plan on giving Harry's a try at the next event.

The only problem I've had is when a call comes in and I'm on track it stops the timer.

FruiTay

Whoa I love the info it gives with the lateral G's and MPH! I gotta get this!

NOSLO6

I use the Do Not Disturb feature in the recent iOS to take care of that problem.

mrc24x

Nice! Thanks for the tip.

blkbrd69

Same here +1

X25

I use RaceChrono for Android. It is FREE, and is better than Trackmaster when it comes to accuracy and analyzing the recorded laps. After all, Trackmaster's data format is also known as "RaceChrono"; one has to wonder why

I used both, and am settled with RaceChrono.

P.S. I use DashWare for syncing and overlaying the lap data onto the video(s). For final rendering, I use Sony Vegas Platinum HD blah blah (it has a long name).