Lap timers - Harry's?

[mazmad]

I know there are 1,000 threads on this, ok I'm lazy.

Looks like I need to get myself a lap timer. Is this a good one to get for my iPhone? Do I need an external GPS or is the onboard good enough?

(It is a stop gap until I get a proper dash logger).

[PhilM]

The iphone GPS is only 1hz and you need a higher refresh rate - say 10hz.
I have a Skypro 160 external GPS as I use it for other mapping, so i downloaded Harry's Laptimer. It seems to have most Australian tracks. I have not used it on the track yet - 1st time probably at Lakeside at Natmeet - so I will report on how it goes.

[manga_blue]

x2 You need at least 5Hz and preferably 10Hz for lap timing. Qstarz make the most popular blue toothreceivers around. Their BT-Q818XT is the current version of what most people use.

Obviously my inexperience with iPhones is showing, I've only had Androids, but doesn't the screen shatter and the battery get wet when you touch it to enter the track name on an iPhone (or perhaps do anything at all with it really)?

[zero00]

'Harrys' is quite accurate, I ran mine at both Lakeside and QR before their new system of transponders came in and I only have an I-phone 3 or whatever you call it!

For those going to Natmeet and running at Lakeside you will use a transponder attached to the front of the car that sends signals to the tower - for those that also have the 'lapceiver' it updates almost immediately you cross the start/finish and stores I think 2,800 laps in 5 separate memories - I attach mine in front of the tacho and when I cant see the needle I know i'm over 7000rpm!

For ayone that will be there on the 14th, look me up - silver NB8A, car #141 in the pits and I will show you. I have arranged for a lapceiver for Bryan to use and evaluate with huge thanks to 'trackphotos' who will not be running, but there on the day

To close, 'Harrys' with an I-phone will do the job!

[mazmad]

Thanks guys will check out those doodads. For the iphobes......huh?

[rossint]

I use Harry's, it's very accurate using the internal GPS of my iphone 5. I use it at sprints along with a Dorian transponder and while it's not 100% it's always within a few 100ths which is more than accurate enough for me. The only problem I've had with it is it occasionally will miss starting a new lap when you pass the start finish but that's very rare.

[Celluloid Retina]

I'd recommend the Performance Box... that's what I have in my car. You should look into it.

But seriously, I've also got Harry's Laptimer Pro (Petrolhead eddition) on my iPhone 5, which is what i've used up till now. As a stop-gap measure for $30 something, you can't go wrong. As Manga Blue said it only uses the internal 1Hz (1 sample a second) GPS but that's fine for lap timing. It manages to be within a 10th of a dorian the majority of the time.
Where its a little weak is the telemetry side of things, measuring V-mins and G-loadings through corners because it only samples this stuff once a second, which on most corners is only 2-3 samples, not enough to give you an accurate picture about where you went better or worse. But if you couple that with an external GPS reciever (5-10 Hz) all that stuff would come to life.

Its great in that you can point it out the front and do video recording, that then overlays all your data over the track lap for later viewing. Downside of that is, it's using the GPS, the video camera, the screen, the internal motion sensor and you can expect about 40min usage from a full battery! So has to charge between sessions.

For $30 odd, go for it, you won't be disappointed.

Stu

[Trackphotos]

Where its a little weak is the telemetry side of things, measuring V-mins and G-loadings through corners because it only samples this stuff once a second, which on most corners is only 2-3 samples, not enough to give you an accurate picture about where you went better or worse. But if you couple that with an external GPS reciever (5-10 Hz) all that stuff would come to life.

1Hz is pretty much worthless, to be honest I'm surprised it's even useful for lap times at all. I found Racechrono to be pretty inaccurate so I didn't bother using it until I got an external GPS. Then, excellent. Telemetry at 1hz is a waste of time, even at 10hz the G force readings are poor, you really need to use the internal phone accelerometers rather than calculated G's through GPS position. It's only about $80 for a Qstarz 818XT though so couple that with one of the free apps and you've got excellent, accurate data for under a hundred bucks. Still would like to get my hands on a performance box though.

[oztrackdays]

VBOX Sports http://www.vboxaustralia.com.au/VBOX%20Sport.html
works by itself and it's battery Powered.

Chain it to HLT via Bluetooth and then you have best of both worlds.

If your car has OBD get a Wifi OBD reader HLT will talk to that and then you can be in geek petrolhead heaven.

[mazmad]

Don't think OBD is an option for me.

Video with Harry's would be cool. My car used to be wired for accessory power not sure now $30 sounds like a good stop gap until I get something more permanent.

[Magpie]

+1 for the Vbox stuff, they also have a new product out a 20Hz GPS Data Logger and Predictive Lap Timer Display in one. http://www.vboxmotorsport.co.uk/index.php/en/products/performance-meters/vbox-laptimer

I use the VBox Lite that also accepts RPM and up to 4 x 5 volt linear sensors.

[mazmad]

The vbox stuff is good. But I am after an el cheapo stop gap until I buy a dash logger, like an AIM G4 or Racepak.

[Magpie]

Good plan, I should have done the same before I went with Innovate and VBox. It takes a bit of time to sync the Innovate and Vbox data up and an all in one soltion would have been better. However the VBox can take CAN iputs from the ECU so this maybe a thought for you later. The VBox Lite can do up to 8 CAN channel inputs and the VBox Pro up to 32.

[mazmad]

Thanks good to know. It is an impressive bit of kit, especially with the video. The G4 Aim is a good simple dash/logger, not super expensive (none of this stuff is cheap).

[PhilM]

Qstarz are only for Androids not Iphones -