View Single Post
Old 03-26-2008, 08:50 PM   #1
ChrisZang
Registered User
 
ChrisZang's Avatar
 
Join Date: Mar 2006
Location: San Carlos, CA 94070
Posts: 1,450
experience with GPS based lap timer system

Well, the track season has started again - at least for us on the West Coast while some of you are still digging out from your snow covered Igloos - and what a great day I had last Wednesday in Laguna Seca

Last year I picked up a Longacre lap timer but I just wanted something with a bit more oooomph than a simple infrared timer, so I did a bit of research and looked into GPS based lap timers. A buddy of mine wasn’t too happy about his expensive GPS timer, so I looked for other solutions.

What I finally settled on is this:
• External Bluetooth GPS module (10 Hz sampling rate) http://www.semsons.com/wigiwblgpsre.html ($70)
• The data logger software http://www.maxqdata.com/ ($79) which needs a Bluetooth enabled Windows Mobile device (well I am lucky here as my “SmartPhone” (Verizon XV6700) happens to be such a device)

Now about my experience:
IT WORKS GREAT!!!

Overview of the most important features:
Displays during driving in LARGE FONT

Lap #
Speed
Lap time

Starts/Stops logging automatically; as soon is the car faster than 20mph or slower than 15 mph, no pressing of buttons
Detailed recording of a myriad of data for each lap in 1/10 of a second intervals (calculates laptimes down to 1/1000 of a second)

Accurate lap timings
G-force calculation
Records your speed
Sector timing
Allows you to compare two laps side by side
For endurance races it can e-mail “telemetry data” while the car is actually still on the track

The results can be either analyzed on your Pocket PC (meaning right after the session) or at home on your PC
And the BEST feature is called “time since you last been here”, that means exactly what it says, it’s like you have an unlimited number of beacons on the track. This is where it comes in handy: You always wonder if you are faster or slower if you take turn 2 in Laguna Seca as a dual-apex. Well let’s try it: Your last lap was done with single Apex in turn 2, now have a quick look at the timer BEFORE you enter turn #two: 1:56:00
Now do your dual-apex and have another look AFTER the turn: 1:57.50, you just LOST 1.5 seconds, back to single apex we go ;-)

see attached images


You can export the data into Google Earth format and look at your “traces” in Google Earth:

see attached images


And last not least if you like to record and publish videos of your track days, and you figured out that you still have some money left in your budget ($195) then you can beef up the video using the data and the software called “Trackvision” (http://trackvision.net/ ) and you can produce “Formula 1” style videos, example: http://www.youtube.com/watch?v=OiWR2heYIbU and in total you still spent less than you would have spent on other GPS based solutions.

Cheers & Happy Racing
Christopher
__________________
I still wave at Boxsters, but they no longer wave back :-(
2002 Boxster S "Violet" (sold but not forgotten)
2009 Carrera 4S "Kelsey" (current ride)
2015 FIAT 500e "Nikki" my commuter car
ChrisZang is offline   Reply With Quote