This is the way to go.......

Scott

John,

I want it! I can stop by today or Saturday, if you're around?

Patrick

Therein lies the problem... Cell service is so weak, we're not even able to get the GPS to work on the phone out there... A true GPS would work with satellite coverage, but the cell phone GPS still uses cell phone repeaters or wifi...

AIM Solo sold to Patrick!

It is indeed. App based laptimers/dataloggers are a lot more interesting and reliable with one of these:
Dual XGPS150A Universal Bluetooth® GPS receiver for portable devices at Crutchfield.com

With a bluetooth GPS receiver, no cel service is needed so you get 100% hi res GPS signals everywhere. You don't even need a phone. An ipod Touch or older WM PDA works just fine.

If all you need is a simple GPS laptimer with limited function, the AIM Solo is a good tool. If you want more sophisticated data comparisons like:

Shift points
Corner entry speeds
corner min speeds
corner exit speeds
braking zones
sector comparisons
graphical lap comparisons with best lap/optimal lap
video with automated data overlay
Oil temp display
RPM display
boost pressure

An app based datalogger with external hi res bluetooth GPS offers a lot of bang for the buck but it is clearly not for everyone. As the tools get more sophisticated, the learning curve is a little longer, but it's a worthwhile effort IMO.

Choose the tools that best meet your needs.

It's odd. The GPS puck for my data logger finds gobs of satellites and has no issues at all. The external satellite pickup I got for the iPhone only finds 3, which I think is the bare minimum. It seems odd that the lap timing apps would utilize cell tower signals, but there you go.

I have the Dual XGPS150A receiver that Cajundaddy mentions.

I'm all thumbs when it comes to this technical stuff, but it's frustrating when I get intermittent results from both my infra-red based Ultralap (especially in the late afternoon) and the GPS-based stuff in/with the cell phone. My solution was going to be to get a display unit for my Race Technology DL1 data logger. But that's going to involve some risk, since my DL1 is old enough that I need to re-flash the unit in order to be compatible with the display. And doing that MIGHT cause the DL1 to freeze up, which the company says it MIGHT be able to revive. :rolleyes:

Maybe we can trade talents Jack. I'll help you get your Datalogger App all up and running, tracks entered, bluetooth GPS handshake confirmed with 9-10 satellites visible and 100% reliable. You can help me design and build out my garage. :D

Not accurate, but a common misconception.

Confusion comes from a few areas...

All Apple iPhones and most Apple iPads have stand-alone GPS capability. Apple devices with cellular capability have a dedicated GPS capability and can geolocate even with no cell or wifi signal. In fact no data or cellular plan is required... You just have to buy the models that have cellular capability.

Wifi Only iPads do not have GPS chips. Only iPhones and iPads with 3G/4G/LTE have GPS chips. If you buy an iPad with wifi and cellular, it has a GPS chip. If you buy an wifi only iPad, it does not have a GPS chip.

A-GPS (Assisted GPS) uses, but does not require, cell towers. Apple products with GPS chips will try and use a technology called 'Assisted GPS'. A-GPS provides additional accuracy and reduced satellite fix times by using the known locations of cell towers and wifi networks within range. If there is no data connection, the standalone GPS will still provide a fix, it just won't fix a new location as quickly.

Even devices without GPS chips can geolocate. Using cell tower triangulation and known wifi networks, devices without GPS chips can still geolocate. This is not the same as A-GPS and this is not how iPhones and iPads work, except for wifi only iPads. On these devices, if you have no data connection, you have nolocation info. Unless you tether an external location enabled device...

Confusing! So Apple devices with cellular chips also have standalone GPS chips. Apple devices without cellular chips do not have standalone GPS chips. And Apple describes their GPS technology as AGPS which uses cell towers as well as satellite signals, which sounds quite a bit like the technique cell phones without dedicated GPS chips use to geolocate, even though it is completely different.

• A-GPS is better and more flexible than satellite only GPS. (iPhones and most iPad's use A-GPS)
• Satellite only GPS is better than cell tower triangulation. (Garmin uses sat only)
• Cell tower / Wifi triangulation is better than nothing. (Wifi-only ipads and many other cell phones use terrestrial triangulation)
• High bandwidth GPS signals provide more accuracy for speed and timing applications (Advantage of using something like the Dual bluetooth GPS receiver)
• External GPS antennas can provide much better signals (Where iDevices fall a bit short)

...and one more issue that make it all even more confusing!

Most app store navigation and GPS applications still need a data connection to function. This is not a hardware limitation! If the application does not either preload or buffer map data, they typically will not work without a data connection even though the device is receiving GPS signal. Example of application that allows pre-loading maps: MotionX GPS. Example of application that requires data connection to properly work: Google maps. Example of application that transparently buffers data, allowing it to work if you travel a short distance out of data coverage, but will eventually stop working if you travel too far out of range: Waze.

------

Bottom line?
Harry's lap timer works fine even if you are out of cell phone or wifi range as long as you are not trying to do something that requires data access (like load a track map, upload results, etc). Using an external GPS (like the dual) can provide higher accuracy GPS signals and more accurate lap times. I get a usable GPS signal for lap timing applications both on my custom in-dash iPad mini and my iPhone mounted to a windshield suction mount with accuracy that is fine for my occasional track day and DE event needs, but I'm not looking for super high lap time accuracy.

For casual track days, an iPhone, Harry's lap timer, and a RAM suction windshield mount provides an unbelievable amount of bang for the buck, especially with the video and data overlay capabilities it offers!

Here's a not-so-great lap from a driving perspective, but still cool video. If you already have an iPhone, less than $45 investment to create videos like this?? Awesome!

<iframe width="560" height="315" src="http://www.youtube.com/embed/0NodkbTR_Vg?rel=0" frameborder="0" allowfullscreen></iframe>

Here is a lap of Buttonwillow in my brothers car using Harry's and iphone 4 from last year. A lot of bang for the buck once you sort out the details.

https://www.youtube.com/watch?v=FwGlrzO7Q1I

My suction mount arrived yesterday so I did exactly as you did. Created a test track in the neighborhood and did a few laps to get a feel for the functionality of it. I also picked up a camera connector for the iphone to iPad Mini. This way I can download after each session. My iphone doesn't have the much storage. the iPad does.

Everything worked like a champ. Let's see how it does at Blackhawk next weekend.

Cajun, let me know if you're ever able to get it to work at WSIR, or SOW, as I have not...

It works every time Patrick in both my car and my brothers car. Here is an entertaining lap of WSIR on a set of V710 tires that are well past their expiration date:

WSIR Spin in 2 - YouTube

i realize this is probably a silly question>>>
 

when using harry's via GPS, is the phone buring data, or only if you are dowloading track maps, etc??

Only when you download maps.

I too have had sketchy results from Harry's Track Timer. Sometimes - it's 100% - some track days I'm lucky to get a session with some recorded laps.

<iframe width="560" height="315" src="http://www.youtube.com/embed/OLdspvymJic" frameborder="0" allowfullscreen></iframe>

I've found it helpful to reload the maps after an update - then restart the phone.

I strong mount is a requirement

I've now seen 2 iPhones exit a window on track and end up smashed. Remember to back up your phone if your doing this!

Ended up using Harry's.

<iframe width="560" height="315" src="//www.youtube.com/embed/qjzaXTokgP4" frameborder="0" allowfullscreen></iframe>

Motor sounds good

Thanks. Cat bypass, B&B 1 in 2 out stainless muffler.

<iframe width="420" height="315" src="//www.youtube.com/embed/2dojHatT0os" frameborder="0" allowfullscreen></iframe>

Any recent experience with Trachmaster?
 

Reviving an old thread to see if there is any more recent experience with Trackmaster for Android. I have a Galaxy S4 and was hoping to use this for a DE at Road America. I've read some comments about the results being better with an external GPS. However, I was wondering if this may have improved over the last couple years.

Thanks.
Roger

I just ordered a number of various bluetooth gadgets and plan to run Harry's lap timer next time out... Before doing so, I did alot of reading and Harry's actually has a message board on their site with lots of discussion/Q&A on the app itself, and all the various accessories... I ended up ordering the following:
- RAM Mount suction mount with extended length for GoPro - I have a 991 but with no cage/harness bar. wanted a bit longer mount to mount to rear windshield and extend forward closer to between the 2 seats. I this doesn't work or I get too many vibrations, will do standard windshield.
- SkyPro XGPS160 GPS Receiver - external GPS for more accurate data. Lots of good feedback and 10Hz refresh. Have heard of problems with Andriod defaulting to phone GPS, but I'm apple so didn't research as much.
- Dual XGPS 160 Mount (F53ZDEXN9) by mculik - basically a guy designed a 3D printed mount for the external GPS which attaches to the RAM camera mount. Better than using tape on the dash/window...
- GoPoint Technology 9105 BT1 - bluetooth OBD reader to provide car data to Harry's.

Everything except the GPS mount I bought on Amazon, and it was like $250 +/-? More data than I need, or can effectively utilize at my current experience/skill level, but I find data cool and invaluable...

I'm also planning to use the GoPro for video instead of my phone, and Harry's can control the newer GoPro's which helps with integration and synching... Literally just ordered, I'll see how it goes next time out!