Lap Timing Equipment

[semislickR32]

Hi,

I am looking at getting a lap timer for the GTR for trackdays, sprints etc - I get sick of waiting for the official times to be posted, often hours/days after the actual lap, and so its difficult to feedback into improving times. I'm not a pro racer or anything but have recently become OCD about shaving those hundredths off my PB

I've had a look at the Performance Box and used a borrowed mychron at a recent trackday which are GPS and beacon respectively. I've also tried the "Trackday" iPhone app which on my old 3G was absolutely useless.

I'm leaning towards the mychron, but was wondering what experiences you guys have had with these or any other lap timing devices in the same price range (eg $500-900?). Are they usefully accurate? Are beacon timers more accurate than GPS-based ones? What would you recommend if price is no object? or what's best bang for buck?

(ps yes have used search and found references to the above but nothing definitive)

Cheers

[fake400r]

Hi,

I am looking at getting a lap timer for the GTR for trackdays, sprints etc - I get sick of waiting for the official times to be posted, often hours/days after the actual lap, and so its difficult to feedback into improving times. I'm not a pro racer or anything but have recently become OCD about shaving those hundredths off my PB

I've had a look at the Performance Box and used a borrowed mychron at a recent trackday which are GPS and beacon respectively. I've also tried the "Trackday" iPhone app which on my old 3G was absolutely useless.

I'm leaning towards the mychron, but was wondering what experiences you guys have had with these or any other lap timing devices in the same price range (eg $500-900?). Are they usefully accurate? Are beacon timers more accurate than GPS-based ones? What would you recommend if price is no object? or what's best bang for buck?

(ps yes have used search and found references to the above but nothing definitive)

Cheers

Ive been using performance box and has been great so far. Havent even started to undersand all the data logging yet but ill get there.

I will be interested to see what times it spits out compared to the lap time at GSR/EVO time attack this monday.

Ill keep ya posted

[semislickR32]

Ive been using performance box and has been great so far. Havent even started to undersand all the data logging yet but ill get there.

I will be interested to see what times it spits out compared to the lap time at GSR/EVO time attack this monday.

Ill keep ya posted

cool thanks. I understand the GSR/EVO track timing is done using the mychrons - the one i used was one SAU borrowed from them for the trackday back in April.

[Kaido_RR]

i use the performance box, very easy to setup and used.

only problem i found is that to setup splits etc on the lap, you need to drive around the lap and press the button on the box everytime you want a split, which is kind of hard to do if there is aheap of guys racing on the track at the same time.

However once its setup its good to go! you can save the split/track and just load it up everytime you need it.

The new software that comes with it is pretty awesome, i use google map and trace out the local track so it can show you your lines. google map was abit off but you can adjust it with the software.

has lots of features so you can see were your accelerating, braking etc etc

here are some screenshot i took, 1st one is comparing my lap to my friends lap (just put the box in his car and off he went)

this is the race line trace on the track

[Ant97GTR]

I use the mychron just to give me an instant lap time so I know if what I am trying is faster or slower. So far it has been spot on compared to the transponder timing and gives me the instant feedback I am after.

If you are after data and splits etc this obviously isn't for you.

[Angus Smart]

i bought one of these a while back

http://www.xtracing.com/ the one on the left. works great! you can get all software stuff for it aswell.. works off a beacon that you buy separately

used on the kart and on the car

Just noticed they have a new one too.. looks alrite!

[hrd-hr30]

Are beacon timers more accurate than GPS-based ones?

definitely. the trigger is in a fixed location physically on the track/pit wall and triggered as the car actually passes it.

GPS timers rely on Points Of Interest for locations on the track (eg start/finish line, splits etc) which in reality will most likely not be recorded exactly on the track, in which case a hypothetical line through the GPS POI is what triggers it. And say your GPS is operating at 1hz, its only updating your GPS position once every second. At my local track I cross the start/finish line at approx 200km/h. In that second where my GPS lap timer needs to stop one lap and start a new lap, I've covered over 55m. So it needs to interpolate those 2 GPS positions and speeds at those points, roughly calculate the acceleration (probably linearly), to work out when you crossed that line perpendicular to the Start/Finish line POI... Having said all that, they can get pretty decent results! But a beacon lap timer is more absolute and accurate. Its not having to do anything except count time and wait to be physically triggered.

[MrStabby]

If you want cheap, then iphone app is the way to go. I use HarryLapTimer with the Tomtom cradle (on 3GS). Other option is to jailbreak and use a bluetooth GPS. Using an iphone with the internal GPS only is a waste of time, as you found.

[benm]

i use the performance box, very easy to setup and used.

only problem i found is that to setup splits etc on the lap, you need to drive around the lap and press the button on the box everytime you want a split, which is kind of hard to do if there is aheap of guys racing on the track at the same time.

I've never had this issue, just load which ever track im at and soon as I start driving it automatically starts timing and uses the loaded track data for the splits and start/finish and it displays them everytime I go past that point without touching any buttons.

The split times is brilliant for people like me that are beginner track drivers but wanting to improve. You drive past the first split time and know instantly how you are doing, if you are a second off you know that driving at 110% for the remainder of the lap is going to do anything so you back off a couple of seconds to save the tyres/brakes. The beacon timers give you no info until you cross the start/finish line, infact they give you no info at all, just your actual time. When you get home and analyse your times you cant remember why you did those times because you dont have the data to show you.

As you mentioned the PerformanceBox is really good because of the data it saves to memory card. Just taking a look at the data of my 3 fastest times its amazing how much difference their is in the actual data (corner speeds, corner lines, straight line speed etc) it's all very close yet so far apart (1km/h here and there makes a difference) when you are chasing time.

Don't forget the PerformanceBox is more than just a laptimer, I dont have a speedo in my aussie car so I use it as my speedo, you can buy additional components to record temperatures etc and it does your 1/4 mile times as well.

[hrd-hr30]

If you want cheap, then iphone app is the way to go. I use HarryLapTimer with the Tomtom cradle (on 3GS). Other option is to jailbreak and use a bluetooth GPS. Using an iphone with the internal GPS only is a waste of time, as you found.

yeah I tried HarrysLapTimer app for the first time the other weekend just with the built-in GPS. Hopeless.

so it works well for you with the TomTom cradle? If so, I'll have to get one. Even paying $159 for the TomTom cradle still makes it a cheap lap timer.

[semislickR32]

yeah I tried HarrysLapTimer app for the first time the other weekend just with the built-in GPS. Hopeless.

so it works well for you with the TomTom cradle? If so, I'll have to get one. Even paying $159 for the TomTom cradle still makes it a cheap lap timer.

if it works well it would be pretty cool - the current version introduced video recording and apparently the "next" version will have overlay:

http://www.youtube.com/watch?v=FYL4PZsVLC8...layer_embedded#!

pretty neato if the actual GPS function works...

Still don't know - I like all the extra data logging and mapping stuff that comes with the performancebox over the mychron, although it's all totally unnecessary so is knowing the lap time, so might as well!

Will do some more research on the HarrysLapTimer option with a GPS cradle...

[Noddy]

I use an old MyChron with a beacon. I like it. A friend of mine has a new with track mapping, the whole shooting match, dash and all. He has found it very helpfull to overlay laps with different with different setups to compare and see how they compare. I like it too. Might get 1....1day.

[LSX-438]

i've used a few different lap timers, including the beacon style and GPS timers, over many many track days. nothing comes close to the GPS variety for convenience and analysis. looking at real-world results (dorian vs beacons vs GPS) for my money there is nothing in it (in terms of accruacy), maybe a tenth here and there). get a GPS timer, they are great. can't tell you how many times i've left a beacon at the track, or had one stolen.

[MrStabby]

yeah I tried HarrysLapTimer app for the first time the other weekend just with the built-in GPS. Hopeless.

so it works well for you with the TomTom cradle? If so, I'll have to get one. Even paying $159 for the TomTom cradle still makes it a cheap lap timer.

Works for me no problems at all. I didnt have a satnav so the cradle has a dual use for me. I have also used racechrono with a nokia bluetooth GPS before i got the iphone and it worked well, but was less convenient.

Also, GPS based means you can get speeds/cornering Gs etc that you cant get from a beacon.

[ssxRicho]

hard to go past a $150 nokia mobile, $100 5hz gps and racechrono.

you can export the data into vbox format then look at it through performance tools.

put it inside the car so you can see it, flashes red or green on the screen through the sectors so you know

if youre going quicker.

through it in mates cars as well.

see Brendan's videos, he has it attached to the steering wheel.

[hrd-hr30]

Works for me no problems at all. I didnt have a satnav so the cradle has a dual use for me. I have also used racechrono with a nokia bluetooth GPS before i got the iphone and it worked well, but was less convenient.

Also, GPS based means you can get speeds/cornering Gs etc that you cant get from a beacon.

cool. I'll give it another go. Thanks Stabby

[Marlin]

I had a terrible first experience with HarrysTimer last friday...... let me know how you can make it usable when you work it out Harry!

[hrd-hr30]

will do mate. I have a speed limit defender on the way for the Aristo, so I might try it out on that at the next Lakeside sprint lol

[Angus Smart]

hard to go past a $150 nokia mobile, $100 5hz gps and racechrono.

you can export the data into vbox format then look at it through performance tools.

put it inside the car so you can see it, flashes red or green on the screen through the sectors so you know

if youre going quicker.

through it in mates cars as well.

see Brendan's videos, he has it attached to the steering wheel.

+1

racechrono is the goods. i have used it for picton kart track before. but no other motorsport.. and a little bit of driving and logging on the street.

[Beer Baron]

depends what you want. if you just want convenient, 100% accurate and reliable times then the beacon based mychron timer is the go. I have a mychron light TG ( it was around $300 from memory) and it does exactly what's advertised. it can also do splits as well with additional beacons (around $50 from memory). it's also super easy to read and easy to use.

http://www.aimsports.com/products/tg/index.html

on the other hand if you think you want to delve further into analysis of your driving then you really need something with more functionality like a drift box/performance box. or even some more logging stuff like vbox pro etc.

in your first post you said you just want quick laptimes as you're sick of waiting for the sheets at track days etc. if that's really the case then the mychron is for you. the other good thing is. they are very popular. at any given track day there will be plenty of mychron beacons on the pitwall. you can just pick one and use that (providing they don't pack up and bail half way through the day! saves putting your own out there if you are worried about forgetting it).