Question for Harry's Lap Timer Users

[M3 Montreal]

Back when I purchased the app they recommended the Tom Tom cradle for improved accuracy.

I find it works great but is there a more accurate mount thy is now recommended?

Edit ** found my answer. There are now new attachments available to improve accuracy.

[von_zoom]

Seems to be getting a little more imvolved than downloading the program. Now, as I understand it, in addition to the program, the mount, and the iphone 4S, I will need (or simular to) a Emprum Ult. GPS unit, and a PLX KIWI device. The $9.00 app (or is the Pro recommended instead) has suddenly gone to $260.00 plus/minus. Am I correct?
I'm slow, but getting there. Thanks for the input.
vz

[Erhan]

Originally Posted by von_zoom

Seems to be getting a little more imvolved than downloading the program. Now, as I understand it, in addition to the program, the mount, and the iphone 4S, I will need (or simular to) a Emprum Ult. GPS unit, and a PLX KIWI device. The $9.00 app (or is the Pro recommended instead) has suddenly gone to $260.00 plus/minus. Am I correct?
I'm slow, but getting there. Thanks for the input.
vz

You are correct. I'd suggest the pro version, worth the difference.

The external GPS (like Emprum UltiMate) is recommended for increasing accuracy and refresh speed. This is ~$100

The KIWI OBD2 is recommended for capturing throttle/brake data. This is ~$150.

In my opinion, the external GPS is much more important than OBD2 data. I'd rather know my speed through corners in different laps more accurately than what was the throttle position. Since the speed changes are recorded with (I think...) GPS data, you see where you braked, and where you started accelerating anyways.

You can analyze your lap data in many ways: directly in iPhone, in iPad (you have to buy the iPad app) or on you PC for example with ChaseCam. It can compare laps, so you can see what have you done better in your fastest lap. Again, if you braked earlier/later in a given lap compared to your fastest lap, it is very easy to see. I attached some iPhone screen shots below.

The red one is the fastest lap. These are showing speed (not speedo but GPS speed) and as you can see, you know where you braked etc. You just don't know what is the brake pedal position (and you may not know this even with KIWI, because it is up to the car which data it transmits). You can also see things like lateral/lineal Gs, elevation change etc.

The whole track:


Zoomed-in to Turn 2:


Zoomed-in to Turns 5a-5b-6. You can see differences of taking different lines:

[FrenchBoy]

Originally Posted by von_zoom

Seems to be getting a little more imvolved than downloading the program. Now, as I understand it, in addition to the program, the mount, and the iphone 4S, I will need (or simular to) a Emprum Ult. GPS unit, and a PLX KIWI device. The $9.00 app (or is the Pro recommended instead) has suddenly gone to $260.00 plus/minus. Am I correct?
I'm slow, but getting there. Thanks for the input.
vz

All depends how much data you want. All I have is the App and the mount. I get a lot of stuff already. Internal GPS mostly works fine. You may want to start with that see if you need more after.

[von_zoom]

Originally Posted by FrenchBoy

All depends how much data you want. All I have is the App and the mount. I get a lot of stuff already. Internal GPS mostly works fine. You may want to start with that see if you need more after.

I was just about to ask that very question, if right out of the box the Pro app would be satisfactory if secured on a good mount.
Appreciate the assist.
vz

[Z K]

I just use a $6 iphone windscreen mount from Ebay. Works fine. No need to go overboard with add-ons to get started. All you need is the Pro version app.

You can set your own course and start timing laps around your neighborhood..

[von_zoom]

Originally Posted by Z K

I just use a $6 iphone windscreen mount from Ebay. Works fine. No need to go overboard with add-ons to get started. All you need is the Pro version app.

You can set your own course and start timing laps around your neighborhood..

Thanks, I will be running and terrorizing my neighborhood tomorrow
vz

[Sleeper519]

This is such a timely thread! Just got an iphone 4S 32G, and was looking to download Harry's lap timer and get a mount but didn't know all the particulars--just stumbled on to this piece. Thanks all, for the above tidbits!

[LateBraking]

Originally Posted by von_zoom

Seems to be getting a little more imvolved than downloading the program. Now, as I understand it, in addition to the program, the mount, and the iphone 4S, I will need (or simular to) a Emprum Ult. GPS unit, and a PLX KIWI device. The $9.00 app (or is the Pro recommended instead) has suddenly gone to $260.00 plus/minus. Am I correct?
I'm slow, but getting there. Thanks for the input.
vz

Not really, I tested Harry's app with lap timing at a track back-to-back and with the iPhone 4's internal GPS time deviation was about 0.1-0.2 seconds, so a Emprum unit (I actually used TomTom until support was dropped for it) and KIWI are not strictly necessary.

Emprum will just increase the lap timing accuracy, and KIWI will simply add data such as brake and throttle positioning information to your video overlays. With just the iPhone and a suction camera mount that I got at Target, (the TomTom is now just an expensive paperweight), I am able to get fairly accurate lap timing, data on G's being pulled through the iPhone's internal accelerometer (AFAIK there's no upgrade to this), and my speed through sectors of tracks (accuracy seems somewhat dependent on the points of interest created by the creator of the track maps you download) which looks something like this:

[Erhan]

Originally Posted by LateBraking

and my speed through sectors of tracks (accuracy seems somewhat dependent on the points of interest created by the creator of the track maps you download) which looks something like this:

I think this is the part where having a faster GPS unit helps. You get more of those points, each with your coordinate and speed. And I bet external GPS have better accuracy as well.

I think the points of interest (like the turn names/numbers) are just there as a reference for you. The only thing that is crucial is the coordinates of the start finish line, so that HLT can create lap time data. All the rest (speed, position) are just recorded GPS readings.

In fact, if you get out of the track, or do a shortcut and come back to track, you will see that on the google maps as well.

Below pics are taken from HLT's website:
http://www.gps-laptimer.de/GPS_and_Accuracy.html

LEFT: iPhone's internal GPS RIGHT: External GPS

[LateBraking]

Originally Posted by Erhan

I think this is the part where having a faster GPS unit helps. You get more of those points, each with your coordinate and speed. And I bet external GPS have better accuracy as well.

I think the points of interest (like the turn names/numbers) are just there as a reference for you. The only thing that is crucial is the coordinates of the start finish line, so that HLT can create lap time data. All the rest (speed, position) are just recorded GPS readings.

In fact, if you get out of the track, or do a shortcut and come back to track, you will see that on the google maps as well.

Below pics are taken from HLT's website:
http://www.gps-laptimer.de/GPS_and_Accuracy.html

LEFT: iPhone's internal GPS RIGHT: External GPS

Oh nice, I didn't know about that. Thanks for that actually.

So, while still not a requirement, external GPS just became a little bit more nice to have.

[von_zoom]

Is there a need to have the iphone stuck to your windshield? Could the iphone be custom mounted to a tri pod behind the front seats so as to provide a wider view of track and driver, like I do with my normal video camera? What would you loose by doing this?
Thanks
vz

[LiM3y]

Originally Posted by von_zoom

Is there a need to have the iphone stuck to your windshield? Could the iphone be custom mounted to a tri pod behind the front seats so as to provide a wider view of track and driver, like I do with my normal video camera? What would you loose by doing this?
Thanks
vz

You can buy i-phone tripod mounts such as this:
http://www.amazon.com/dp/B0056C4VRK/...hvptwo=&hvqmt=

[Erhan]

Originally Posted by von_zoom

Is there a need to have the iphone stuck to your windshield? Could the iphone be custom mounted to a tri pod behind the front seats so as to provide a wider view of track and driver, like I do with my normal video camera? What would you loose by doing this?
Thanks
vz

See my previous post. GPS unit (whether internal or external) needs to have direct path to the sky. Otherwise you will loose accuracy.

If you buy the UltiMate, you can buy a 6ft iPhone extension cable, so that way you can mount the iPhone behind the front seats, and run the cable to the roof and attach/tape the UltiMate to the roof.

[von_zoom]

Got my new iphone 4S, downloaded the Pro Harry Lap App, getting my mount ordered this week end, so soon, I will be ready to go. Now, to learn how to use my iphone - it never stops.
vz

[LiM3y]

Originally Posted by von_zoom

Got my new iphone 4S, downloaded the Pro Harry Lap App, getting my mount ordered this week end, so soon, I will be ready to go. Now, to learn how to use my iphone - it never stops.
vz

You will not get any faster on an i-phone by wearing cool driving gloves.

[von_zoom]

Originally Posted by LiM3y

You will not get any faster on an i-phone by wearing cool driving gloves.

You have now moved into advance. For me, I see some much needed lessons on the horizon.
vz

[bigjae1976]

To everyone with the Ram mount...how do you position it on the windshield so the base doesn't show up in the video?

Last question...how do you pull the entire video and delete it? I couldn't figure it out.

While waiting at Best Buy for 1 hour (worst place to buy a cell phone) to reactivate my phone...I noticed a clip on camera lens for the iPhone. Would this help?

http://www.bestbuy.com/site/olloclip...&skuId=4295223

[dogbone]

I have HLT Pro on an iPhone 4S and use the Emprum UltiMate GPS device. A few weeks ago, I was at Willow Springs Big Track and compared it with a transponder. From all the times I checked, the transponder and the Emprum were always within 3/100 of a second of each other and sometimes within 1/100. Pretty amazing!

I'm quite satisfied that when the Emprum is providing Differential GPS to the iPhone, it is EXTREMELY accurate. (Differential GPS means that the GPS receiver is not only tracking satellites in the sky, but also ground-based stations for even more accuracy.)

I use a $5 windshield mount from Amazon to hold the iPhone on the windshield. Works great!

[Sleeper519]

Slightly OT---Anyone know if the iphone 4S can actually accommodate an external microphone?

[sleepless]

Originally Posted by Sleeper519

Slightly OT---Anyone know if the iphone 4S can actually accommodate an external microphone?

Yes. It needs to have a four point jack, like the one on the headphones that come with the phone (or, an adaptor). I just use the mic in the headphones. Google "iPhone microphone"

[Erhan]

Be careful about how grippy your iPhone mount is. Otherwise your iPhone may fly through the side window during hard cornering and you may spend 1 hour to find it.