Lap timer

[xxaarraa]

Whoa, just saw that it's 20 bucks.

Not sure I'd pay that much for a lap timer app.

I got "Track Day for iPhone" for 5 bucks, their Pro version is closer to $20 I think, which gets you more tracks or the ability to "learn" them (or you can buy tracks one by one for 2 or 3 bucks).

Before I continue, I'd say to try Pirelli's free "Diablo Superbiker" app before you buy anything. I only found out about it after I paid for mine and I tried to run them both to compare, but Pirelli's app doesn't seem to run in the background (whereas I can do whatever I want while "track day" runs in the background. Pirelli's app is supposed to give you neat things like lean angle if you mount it in a fixed spot, but I usually just stick my phone in a pocket on my leathers.

I've only used mine at NYST (included in the $5 version, if I recall). It works pretty well, even though my cell service doesn't have stellar coverage up there.

Maybe 1 out of every 3 sessions, a couple of laps are garbage (gps loses signal so the phone doesn't see where you crossed start/finish, or you appear to go a quarter mile off track then zoom back with a top speed of 150+)

I'd imagine that any of the lap timer apps have similar problems.

Lately I've been turning on the app and sticking it in my pocket first thing when I start getting ready for a session - seems to give the GPS time to get a really strong lock and I don't have issues too often anymore.

Here is one of the more accurate sessions I've recorded.

Attachment 39315Attachment 39316

Jeff, your times at NYST are recorded via a phone app??? I thought you had a legitimate lap timer. Yeah, we get the value argument of carrying a phone with you - the phone is one of the cheaper pieces of equipment on you on the track. No arguments there.

But clearly, not all GPS antennas are created equal. A phone GPS is decidely less accurate than a dedicated, purpose-made GPS receiver that's on legitimate lap timers. I won't put too much faith in your lap times recorded via an ifone. So let me play the value argument back to you. You are going to buy a second, third bike, get a season pass, spend a lot of your valuable time on the track, yet you won't drop a couple hundred on a reliable lap timer to get a good read on your evolution as a rider? Doesn't tie.

Just saying.

[nhbubba]

The antenna isn't the issue. The issue is the sampling rate. Phones probably sample at 2Hz at best. Meanwhile the old bt-q1000ex samples at 5Hz and the new ones at 10Hz.

The catch is this may not matter for you. There are ways of interpolating between samples that will probably give you a pretty damned accurate lap time even with a measly 2Hz. There are even some very interesting techniques you can use to compute lap time between two laps without even caring where the S/F line is.

But the moral here is that the sampling rate and antenna design on a smart phone can be more than enough for what we are looking for. I definitely would not discount lap times because they were recorded using a cheezy ass cell phone.

[Jim]

So let me get this straight.....pretty much everybody on here pays $100's to a thousand for a shiny helmet (good for racing a MAX of 5 years), $100's to a grand or two for leathers, gloves, boots....$300 or so for tires (that last ~4-8 days), and a couple grand for a bike......any of which can get totally destroyed by a wrist muscle spasm in the wrong place (not to mention risk of bodily injury or spending a guaranteed $100-200 for track time + gas, etc....

....and I'm "absolutely insane" for taking my cell phone with me on the track? That same cell phone that I pay $4.95 a month for damage replacement?

absolutely, you are insane for doing that. spending hundreds on safety protective gear for the track is no way in comparison to spending money on electronics that you 110% dont need. more specifically, if your $4.95/month phone falls off on the track and caused an incident to another riderf (bike, gear, injury)....we would have serious problems. phones have NO business on a racetrack. Even if it's in your suit & wont fall out, what if you fall and land on it? have you considered the more severe injuries that may occur? buy a legit laptimer and secure it in a way so that your not endangering you or the other riders.

[xxaarraa]

The catch is this may not matter for you.

I have heard this "doesn't matter to you" argument and don't buy it. Regardless of whether I am doing 2:30s or 1:30s, I want my laptimes to be as accurate as possible. On a measure such as lap times, the average amateur Joe has the same precision requirements as Ayrton Senna. Period. We aren't talking tires or suspension or horse power. We are talking about a numerical constant.

There are ways of interpolating between samples that will probably give you a pretty damned accurate lap time even with a measly 2Hz. There are even some very interesting techniques you can use to compute lap time between two laps without even caring where the S/F line is.

Yeah, OK, keep going with this, it's pretty entertaining. All of our times are pretty valuable and spread thin as it is between bike maintenance, driving to the track, tire changes, hydrating, learning, talking. I am not going to the track to mess with interpolating samples and 'estimating' lap times. Sorry.

But the moral here is that the sampling rate and antenna design on a smart phone can be more than enough for what we are looking for. I definitely would not discount lap times because they were recorded using a cheezy ass cell phone.

You haven't explained even remotely logically why the smart phone is good enough for what we are looking for. Last I checked, Apple Computer wasn't the official race timer for Formula 1 or MotoGP. And yes, lap times at a backwoods amateur race track are just as important to know precisely as in Estoril.

[nhbubba]

I don't get it. What's the difference between a $4.95/mo cell phone and a $400 LT-Q6000? Why does it need the QStarz or Starlane brand name for it to be "legit"? All of this shit is just electronics wrapped in plastic.

Properly secure everything on your bike. QStarz timer. iToys. Cameras. Brake calipers. ... Oil drains. Secure it all just the same.

[nhbubba]

I have heard this "doesn't matter to you" argument and don't buy it. Regardless of whether I am doing 2:30s or 1:30s, I want my laptimes to be as accurate as possible.

Maybe we're mistaking accuracy and precision here. What I'm saying is that we don't need 0.001 second precision. For my use the difference between a 1:35 and a 1:39 is interesting. The difference between a 1:35.5 and a 1:35.9 is not. And my impression is that even the fast guys stop counting at tenths of a second.

When a GPS lap timer tells me I turned a 1:35 after a string of 1:39's I believe it is accurate enough for me to feel I done good.

Or maybe I just suck at life. Could be either.

I really do think some of you guys put way too much faith in marketing hype. As Graham points out, all of this stuff is a compromise. Once the device gets a fix, the GPS signals it is working with are common between all of these devices, even shitty cellphones. Accuracy is similar. All the extra, specialized hardware buys you is more precision.

On the other hand, maybe all those 5Hz BT-1000eX'es out there are useless now. If so, feel free to send them my way. I will see to it that they are disposed of.

[Jim]

bubba, accuracy is VERY important for these guys. you know they HAVE to know if they won the track day with their 1:36.152 or 1:36.148 laptimes in the slow group. again....track day

[Ductard]

Jeff, your times at NYST are recorded via a phone app??? I thought you had a legitimate lap timer....
.....yet you won't drop a couple hundred on a reliable lap timer to get a good read on your evolution as a rider? Doesn't tie.
Just saying.

Does that mean they're gonna take away my pole position in the NYST pit-bike race?

My lap times are less suspect than the sub-1:40's being marked by a certain person's girlfriend with a stopwatch.

.....spending hundreds on safety protective gear for the track is no way in comparison....

....if it's in your suit & wont fall out, what if you fall and land on it? have you considered the more severe injuries that may occur? buy a legit laptimer and secure it in a way so that your not endangering you or the other riders.

It's not just expensive safety equipment that I mentioned above. Nonetheless, your safety argument is the one that is most relevant to me, although I'm not sure landing on a flat cell phone (glass covered by rubber and pointing away from my body as mentioned previously) would make a difference with much more chance than what would be considered a freak accident.

Either way, the arguments for a dedicated lap timer do not fall on deaf ears. This is really my second track season and the first I've cared too much about improving my lap times. Right now I've got more time to pick up by working on BP and carrying more roll speed than by comparing my speed on different lines via GPS.

I've gone as far as adding a lap timer to my cart on amazon.com but this is actually what stopped me:

The less expensive Qstarz devices do not log. They are simply bluetooth gps receivers.

I was worried I'd wind up with something that wouldn't do what I thought it would do. I wanted to come on here and see what people recommend, so I guess this thread has prompted me to do so.

Any big difference in the Qstars 1000 series and the 6000 series, other than the $200 price difference and that the 6000 gives you real time feedback while you're riding (flashes green if your lap was a fast one, red if it was a slow one)?

I'm guessing the 818 model falls into the "reciever only but no logging capabilities"?

Do all of the loggers upload to the same computer software for analytics?

I know the sampling rate could be important when you're within seconds of a track record, but I'd imagine the difference between 5 hz and 10 hz is pretty unimportant for a noob.

[Jim]

Any big difference in the Qstars 1000 series and the 6000 series, other than the $200 price difference and that the 6000 gives you real time feedback while you're riding (flashes green if your lap was a fast one, red if it was a slow one)? .

6000 looks like a pager and doesnt have a display. you remove it from your bike at the end of the session and plug it into your laptop to retrieve the data. the 10000 model has a big display and shows data while you're out riding. i know two riders that crashed in a race and wrecked their 6000 Qstarz. they said they'd get the 1000 model if they had to do it over again.

[Gecko]

6000 looks like a pager and doesnt have a display. you remove it from your bike at the end of the session and plug it into your laptop to retrieve the data. the 10000 model has a big display and shows data while you're out riding.

You've got that back-asswards.

BT-Q1000EX

LT-Q6000

[Ductard]

6000 looks like a pager and doesnt have a display. you remove it from your bike at the end of the session and plug it into your laptop to retrieve the data. the 10000 model has a big display and shows data while you're out riding. i know two riders that crashed in a race and wrecked their 6000 Qstarz. they said they'd get the 1000 model if they had to do it over again.

Any chance you got those flipped? The 6000 is the more expensive unit....
http://www.qstarz.com/Products/GPS%2...T-Q6000-F.html

[nhbubba]

The QStarz BT-Q1000eX and the LT-Q6000 are the two 'lap timer' offerings from QStarz. Both are compatible with the QStarz Racing app. (Free download, iirc. You can check it out without a QStarz device.) They have other devices, some with '1000 series' model names. My read of those is that they are NOT SUITABLE for use as a lap timer. Most are 'travel recorders' and sample at very low frequencies (once per second or slower) OR do not log OR are not compatible with the QStarz Racing app. There seem to be some older, discontinued products that seem to work okay as well. But I can't figure out what they may have been.

Really, one of the two 'lap timer' products are the only safe bet if shopping from QStarz.

The -Q1000eX has come in two flavors. The current '10Hz' version and the older '5Hz' version. The difference is one records twice as fast as the other. 10Hz is better than 5Hz, obviously.

The -Q6000 has a color LCD and shows lap time, split data, and some other very helpful metrics. The -Q1000eX has no display and must be connected to a laptop or PC running QStarz Racing to get your times.

In my opinion the -Q6000 is not appropriate for noob or newer track-day rider use. I believe the display is too much of a distraction and leads to pushing or trying too hard. Naturally, this is a YMMV thing. Maybe you have better self control than I do.

My other complaint is that I think the QStarz Racing app sucks. It is Windows OS only and, in my professional opinion, buggy as fuck. It is probably the biggest reason I haven't bought a QStarz timer; their software pisses me off so much.

[Jim]

i do everything ass backwards

[CBR929RE]

unless you use the other features then you're spending twice the money to get your laptimes right on the device with the 6000. I have destroyed one and gotten a replacement at a very good price thanks to great customer service. I don't use any of the other features but its nice to just look at the times right there. still haven't downloaded any data from Classic weekend onto my computer.

[MarkMarine]

I smashed the screen on my starlane and got a new screen from the company for $40. Had it in a week, sent from Italy.

Oh, and iphone and other smart phone GPS are woefully inaccurate. They use wifi to increase this accuracy, but the GPS on it's own on a smart phone is very low power (the amp) very low quality, (because it has to be tiny tiny tiny) and doesn't have an antenna, it's a self contained chip. I'm sure you can imagine the multi-layer circuit board + your body obscuring the chip's view of the sky doesn't make for an accurate or precise reading. And there is a HUGE difference between a GPS designed for precision and accuracy (in cost, size, power needs, and board/enclosure design) and a smartphone, where GPS performance is probably dead last on their feature list.

[jasnmar]

And you can get an external Bluetooth gps for short money to fix that.

Better accuracy and better sample rate for something like $20.00 from China. Is it perfect? No. Show me a device that is.

[xsiliconkid]

Getting back to accuracy/ positioning errors in the data capture using low cost GPS data loggers
Maybe more than you wish to know... (maybe flogging a dead horse)
but, to be truly useful cm accuracy is needed.. (not meters)

It’s important as to what your GPS receiver is capable of. (When working on the RFID lap timing system < as an alternative to the likes of mylaps transponders> I spent quite a bit of time analyzing GPS as a suitable replacement- no such luck)

Summary of GPS Error Sources
Typical Error in Meters (per satellites)

..................Standard GPS Differential GPS
Satellite Clocks.. 1.5 ………... 0
Orbit Errors….... 2.5 ………….. 0
Ionosphere…….. 5.0 ………… 0.4
Troposphere…… 0.5 ………… 0.2
Receiver Noise… 0.3…………. 0.3
Multipath………. 0.6 ………….. 0.6
Total (avg)……... 6 meters…… 1.5 meters
(this means if you brake at exactly the same point each lap, at any given moment the position logged can be +/- the total. So don't go nuts tying to fine tune your analysis of the data.


What is Differential GPS?
In the USA it is WAAS so turn it on if it’s an option.
http://www8.garmin.com/aboutGPS/waas.html
WAAS helps but the ground station can be many miles away from your receiver and therefore the atmospheric path is different. Setting up a base station very close to receivers helps. E.g., NASCAR at NHMS has a very accurate Lon:Lat position on the top of the grandstand and set up their own DIFF base station during events…. It is not used for timing and scoring – enhanced pitbox and TV coverage position on track etc.
e.g., http://support.nascar.com/link/porta...ds-in-RaceView

The other errors not covered by Diff GPS?
There is ongoing R&D going into the last two sources of errors (above). For example, Multipath - the signal bouncing off nearby object before it gets to the receiver. (A bit like the old OTA TV signal ghosting). The receiver can be bombarded by these bounced signals…. Newer receivers attempt to analyze which signal is the direct (right) one. Typically taking the first received signal (as being direct) and eliminating others (but it’s a bit like throwing out the baby with the bathwater). But work goes on….

[Jewcati]

This thread makes me tired....

[Gecko]

Getting back to accuracy/positioning errors in the data capture using low cost GPS data loggers
Maybe more than you wish to know... (maybe flogging a dead horse) but, to be truly useful cm accuracy is needed.. (not meters)

... bla, bla, bla....

Summary of GPS Error Sources

... more bla, bla, bla ... but work goes on….

So I'm back to my original statement ... the Qstarz data logger is a useful tool ... to help stop the wind from blowing the daily race schedule off the workbenches.

So Graham ... how have the OCD therapy sessions been coming along? ... making any progress?

Perhaps a Focus Group might be helpful?

[xsiliconkid]

So I'm back to my original statement ... the Qstarz data logger is a useful tool ... to help stop the wind from blowing the daily race schedule off the workbenches.

So Graham ... how have the OCD therapy sessions been coming along? ... making any progress?

Perhaps a Focus Group might be helpful?

I have your GPS location - so I can probably get within +/- 20'
close enough to see if you hang the toilet paper roll correctly.

[CBR929RE]

So I'm back to my original statement ... the Qstarz data logger is a useful tool ... to help stop the wind from blowing the daily race schedule off the workbenches.

So Graham ... how have the OCD therapy sessions been coming along? ... making any progress?

Perhaps a Focus Group might be helpful?

I think they're good if you're looking for seconds a lap but tenths probably not so much.
as for laptimes mine is usually within a couple hundredths of official race timing.

[Jim]

I spent quite a bit of time analyzing GPS as a suitable replacement- no such luck)

what do the CCS (westhold) transponders use? i know they're much less reliable than the AMB ones. just curious.

[Gecko]

So I'm back to my original statement ... the Qstarz data logger is a useful tool ... to help stop the wind from blowing the daily race schedule off the workbenches.

So Graham ... how have the OCD therapy sessions been coming along? ... making any progress?

Perhaps a Focus Group might be helpful?

I think they're good if you're looking for seconds a lap but tenths probably not so much.
as for laptimes mine is usually within a couple hundredths of official race timing.

I think in addition to [/BOLD], [/ITALIC] and [/UNDERLINE], nesr needs a [/SATIRE] font selection too.

I'm familiar with other's laptimes on Qstarz [usually] being within a couple hundredths of official timing ... which is why I bought one.

And Graham, you must be looking at the wrong place ... I be happy if the people in my house would just hang the damn toilet paper rolls ... correctly or incorrectly!!!

[xsiliconkid]

what do the CCS (westhold) transponders use? i know they're much less reliable than the AMB ones. just curious.

similar to AMB/mylaps.. a decoder goes on a local loop antenna on or under the track - uses a modified RFID battery powered tag..... but mylaps have been at it for years and own 99% of the racing marking because they are so reliable....
In my testing using 900Mhz RFID stick on helmet tag (40cents) and trackside antennas I know I can get 1/1000 accuracy looking at the Doppler shift. When testing at LRRS the lap times were within 1/1000 of mylaps, everylap (except the first lap as the antenna was 10' past the start finish loop.

[Roland]

used it with a dual xgps and it worked like a charm. even posted a video here with it synched up to my gopro. Its an awesome program turns my iphone into a full data acquisition tool. If you get the Petro head version you wont be mad! and you don't have to by maps every track in the world is loaded in.