Lap Timing for Beginners

[bobcowan]

Had a great time in Pueblo. Look foreward to attending more track days. Just for fun, I have no plans for all out competition.

But, like everyone, I would like to get better at it the more times I do it. The only solid measure of performance is lap time. But how does a beginner like myself record lap times? I could have my wife stand there with a stop watch and record them. But I think she would get pretty bored with that. NASA uses a transponder system for groups 3 and 4. But I don't think that will help me.

Do I have to buy a Hot Lap (or similar) system? They generally run about $300-400.

I found one GPS based system that actually looks pretty good. It's called the Driftbox, in case you're interested. It's $750, which looks like it provides some excellent data logging for a bargain price. But maybe a little expensive for simple lap timing.

[Warrtalon]

The point is that you're not supposed to worry about lap times until you've become proficient enough to graduate through HPDE2. Until then, the focus should be on mastering the line, the track, your car, then all 3 at once.

I just graduated to HPDE3 on Sunday and got the chance to use a transponder. It was awesome and worked perfectly, so I got my first-ever lap times. You're right that the lap times give you an idea of how you're doing, but it takes a while to get to that point.

[leggwork]

get smooth and consistently hit the turn-in, apex and exit points, then worry about lap times.
bruce

[bobcowan]

Yes, I understand that. When I have a fast lap, I know because it feels good. I can feel a slow/bad lap, too. So this year and next will be working on more good feeling laps than bad. Time (now) is not important.

But I was looking for some parts the other day, and happened to come across the Hot Lap timers. Just got me to wondering. I didn't think to look at other cars for timing devices to see if anybody had one.

If I'm not working on the car, I'm thinking about it. :) It's a terrible disease.

[ker]

over the years i've known many who used lap timers before they learned to drive. the problem was they would hit a point of no improvement anc couldn't firgure out why they weren't getting faster and others in similar cars were. they were too focused on the timer rather than learning the track and the best way around it. glad to see you knowthe difference. once you get hooked on lap timers, most can't seem to get unhooked.

[Weston]

IMO, there are some other things that need to be covered before worrying about performance, but timing can be useful in learning. As I'm sure we all know, what feels fast may not really be fastest, so it is useful to be able to try something and see if it really was faster or not. However, there are a lot of other variables in the rest of the track (especially with traffic), so it's hard to really judge a change in one segment based on overall lap time. Segment time is really what's useful... there are still some variables in the rest of the track that affects it (ie entry speed/line, brake heat, tire heat, etc), but it paints a clearer picture than just overall lap time.

I've found that a digital video camera (like MiniDV) with a good mount or external camera (like ChaseCam) can accurately tell you your time through any segment as well as the entire lap. It operates at 30 frames per second, which gives you decent precision. However, if the camera is subjected to a lot of shock, it may skip or cut out, which throws things off. I had trouble with that when I had it on a headrest camera mount, but not after I upgraded to the ChaseCam setup. The downside to this method is that it's not instant, or even something that you can really do at the track... I have to get it on my computer, find the frame where I cross each segment marker that I want to use, then take the time indexes and do some simple math. It works really well, but I can't benefit from what I've learned until the next event at that track.

Don't bother with a GPS system for timing... It's too expensive and I really question it's accuracy, since only the military gets the really precise stuff. Stopwatches can be useful, but the human component means that the accuracy is always in question (it's boring and too easy to get distracted or forget what mark you were counting as the start/finish line).

Most people use an infared beacon timing system... you place the beacon somewhere on the track (typically the start/finish line), and a receiver in car gives you a lap time every time you pass the beacon. Some can be downloaded to your computer later. If you have several beacons, you can place them around the track and use them to get segment time as well.

[MHISSTC]

Several folks asked me if I was doing time trials or what my lap times were.

Most seemed surprised to hear me say that, although I was in group 4, I wasn't doing time trials and I had no idea what my lap times were. I got the feeling some of those who were asking were doing the "my car's faster than your car" thing in the back of their minds.

There was such a variety of cars with a variety of modifications and a variety of driver skill, that a comparison of lap times was irrelevant. The only comparison that would have mattered was if someone wanted to compare their own times throughout the weekend.

Just like a lot of other folks, I was having fun just learning what worked best around different portions of the track. Yes, you do get to a point where you can begin to "feel" what is right.

Maybe by next year when I eventually get my CMC car built, I'll be a little more competetive about it and probably care what my lap times are at each track. Until then, I'm just going to enjoy getting each of the new tracks I'll be visiting this year to "feel" good.

[svochuck]

when i first started i would run with other cars, follow there line then get better than they were and move on up to a different/faster set of cars to follow. there is allways someone faster to watch/follow/chase.

chuck

[MHISSTC]

when i first started i would run with other cars, follow there line then get better than they were and move on up to a different/faster set of cars to follow. there is allways someone faster to watch/follow/chase.

chuck


Or NOT follow their line and get better than they are, as the case may be. You can learn a lot from the lead/chase.

[leggwork]

I wouldn't discard a GPS based system - they can be had for 8 or 900 (not chump change, for sure). The civilian ones are quite accurate since 'selective availability' was turned off. And, they only need to be accurate in a relative sense - it doesn't matter if they tell you where you are in the world precisely, as long as they do indicate that you are in the same position (if you are) from lap to lap. They easily give you the segment times which is very useful.
cheers,
bruce



...
Don't bother with a GPS system for timing... It's too expensive and I really question it's accuracy, since only the military gets the really precise stuff. Stopwatches can be useful, but the human component means that the accuracy is always in question (it's boring and too easy to get distracted or forget what mark you were counting as the start/finish line).

Most people use an infared beacon timing system... you place the beacon somewhere on the track (typically the start/finish line), and a receiver in car gives you a lap time every time you pass the beacon. Some can be downloaded to your computer later. If you have several beacons, you can place them around the track and use them to get segment time as well.

[bpanther]

Time for me to chime in....

Video camera is the worlds best (and most common) Data Acquisition system for learning to drive.

GPS systems (I worked for Trimble Navigation for 7 years and they are now one of my main clients) have improved tremendously over the years and have gotten very cheap.

Here is what we use for USTCC to help equalize the cars. You still need to have/buy a pocket PC for a couple hundred bucks, but their base GPS system starts at $199. http://www.maxqdata.com/

[leggwork]

interesting. 4Hz sampling in their basic unit doesn't seem fast enough to be useful - is it?
thanks,
bruce

[bpanther]

Not for suspension work, the details on driving if you were looking at throttle position or measuring engine performance. For the basics like speed in a corner, acceleration/deceleration and the calculated Gs it does it's job at 4Hz.

Since it is all GPS based, this is about the best resolution you can get. To go to a 10Hz rate on GPS costs $$ (dumb - cause all the GPS mfgs do is flip a bit in the software;)).

[jweiss]

Dave - the MaxQdata system looks really interesting. I already have a PPC with Bluetooth, so it would be a relatively cheap solution for me. Will it display lap times in the car? I assume that you just mount the PPC somewhere visible for viewing while driving?

Jeff

[bpanther]

I'm not sure how usefull the incar display would be. We've always stuck the pocket PC away and not used it for real time display.

I'm sure Ed at MaxQ can give suggestions.

[jweiss]

I just spoke to him, sounds like the system is already set up to display lap times on the PPC. Just need to mount it somewhere visible. Also, he confirmed that my PPC with Bluetooth will work. This is a great alternative to hotlap etc. - thanks for the lead!

Jeff

[jweiss]

Here's a screenshot from their web page:

http://www.maxqdata.com/images/iasnap012.gif

There are four different screen configurations, including this one, which does real-time display of two parameters with bar graphs. To display lap times, you simply select it from the pull-down menu (in the image it is displaying lateral and longitudinal Gs).

[bobcowan]

Interesting (but short) article in this months GRM about a GPS based data recorder.