Shit I don’t understand… #6: not timing

There’s a lot I don’t understand about car culture, motorsports, and racing. Help me out.

Lap timers

Last week, when I was coaching at Thunderhill, I overheard a conversation where two drivers were talking about lap timers. They were mulling over the $5 phone app vs. the $500 dedicated devices. I barged in on this conversation because this is a subject I know a little about having owned 5 devices (TraqMate, RumbleStrip, AiM Solo DL, Racebox Pro, Apex PRO) and 4+ phone apps (Harry’s Laptimer Petrolhead Edition, TrackAddict, CMS Pro, Hotlap, and several that are discontinued).

There are 3 reasons to have a lap timer.

  1. To log your lap times
  2. To get immediate feedback on driving “experiments”
  3. To examine your driving after you get off track

My stance on this is that phone-based apps work great for logging lap times. Even though your phone updates its GPS only once per second, you can get accurate lap times to the tenths of a second because the software interpolates your position. I still use CMS Pro and TrackAddict from time to time.

If you want to ask questions such as “if I enter start braking at marker 3 instead of 2, how does that affect my corner?” then a phone isn’t so great. For these kinds of driving experiments, you need a delta/predictive timer that updates several times per second. 10 Hz is common, but some older devices update at 5 Hz and some newer ones are 15-20 Hz. My favorite delta timer is the RumbleStrip DLT1-GPS, which updates at 10 Hz. That’s good enough, and while I’ve never used a 5 Hz device, I’m betting that works fine too.

To examine your data when you get home, you’ll need a data logger. The AiM Solo is a really good product. You’re partly paying for the device and partly for very mature software. I’m very happy with my AiM Solo DL and I use it in the racecar all the time. It also works as a delta timer, but I prefer the giant red LEDs of the RumbleStrip.

No questions?

During the conversation, one driver said he has never timed himself. If this was a rookie driver, I could understand it. But this is a driver who had been attending HPDEs for a few years. And never timed himself? I don’t get it. How do you know if you’re improving as a driver? How do you know if your new tires are better than the old ones? How do you know if weather affects performance? How are you going to answer driving questions without data? I guess by not asking questions. I can’t imagine driving without experimenting. I never go for a drive just for fun because the street is no place to conduct experiments. I guess I’m not a very enthusiastic driving enthusiast.

14 thoughts on “Shit I don’t understand… #6: not timing

  1. I see his point about not timing. Think of recreational skiing. Lots of ski racers ski recreationally. What they gain is a feel for the slip angles, overall balance, recovery, and control. Like performance driving, focusing on the horizon is required.

    Some car racers are that way. A Formula Ford champion I know practices in race karts like a recreational skier. After a session of 10 kart laps, he said “I only did one turn exactly how I wanted to do it”. He knows by feel when it is right. He doesn’t really watch his times.

    Besides, daily track conditions vary with dust, rubber, heat and the will of the gods. Only in a race setting — qualifying or heats — is enough rubber laid down to make the track equally sticky for all, and to make absolute time matter.

    Kind of depends on your personality type: recreational skier, race skier, or scientist skier.


  2. At one point in time I was a recreational skier. But I was always trying to push some boundary or other. Like working on doing helicopters or some other jump skill. Also in skateboarding, I was motivated to learn new skills. Success wasn’t measured by a stop watch, but rather success/failure. But I have to admit, if I was going to skateboard today, I would just enjoy the activity and not try to push my limits. I guess what puzzles me about the non-timed driver is that they have such a mature attitude at the start.


  3. When you’re novice enough, your improvements (or failures) are coarse grained enough that you really don’t need to time. You’re talking about taking a corner at 80 instead of 70.

    Beyond that, I managed to snag a Garmin Catalyst for my track event last weekend and I have to say that it nails the meat of your point. The squiggly lines are there if you want them, but it boils it down to the top three corners where you could make up the most time and suggests, “You know, when you took that corner with a later apex / lighter brake / better rotation / etc, you did better. Maybe do that more next time?”

    Its a stunning example of putting the ends before the means. I’m sure that a lot of people will hate it for that reason.


      1. The Apex Pro seems to work by comparing your performance in any corner to its read of your cars ultimate performance (second hand info, I don’t have one).

        The Catalyst seems to work by observing your actual driving over several laps and observing minor (or major) variations within a particular corner, includes factors like exit speed in the calculation, and encourages you to do more of the stuff that results in better performance.

        Its also the first device I’ve seen with a useful optimal lap calculator. It will stitch together portions of different laps within a session but only in a way that they’re actually linked up, giving you a drivable optimized lap instead of a crazy one based only on sector performance.

        Speaking of which, it also does a good job of defining sectors in such a way that they typically start and end properly on a straight, rather than purely measuring time spent in the corner itself if that makes sense.


  4. This is dangerously close to being political, but you’re expecting others to share your mindset as an academic, specifically a scientist, to ask questions and try to understand things around them. Many people are content to not ask questions and accept things at face value, or don’t care about using data to objectively evaluate their performance.


    1. I would like to think that a sport that is objectively measured with a timer transcends a specific mindset. I recognize that I am wrong about many things though. Much of the shit I don’t understand is obviously based on my specific mindset. Part of what makes people interesting are their contradictions. I have plenty.


  5. I use a VBox with the predictive timing display. The system combines instant feedback (a glance after a turn will tell you if you were faster or slower than your best stored lap) with graphs galore for later analysis. The VBox’s main downside is price.

    The Catalyst seems to be a great product. I wonder what its limitations will be. Can it access OBD data like throttle and brake? Knowing what you (or a co-driver) did is way better than knowing you should go faster.

    Track driving without data collection and analysis can be totally enjoyable, but will make progress slower.


    1. Interestingly, it doesn’t. Its aimed far more at cutting to the chase than most of those products (I also have a Solo 2) and getting to the meat of it – “Hey, in these 3 areas, the biggest difference between your best corner and your average corner was the most significant. When you did better, here’s how you drove differently.” It will tell you things like your angle as you tracked out, but for the most part its trying very hard to skip past the raw data itself and get right to the conclusions that a Peter Krause type person would draw from them. Its certainly not for the total novice who wouldn’t understand how to rotate the car more on corner entry, for example, but its also not aimed at bench racers who want to know exactly that degree of steering input they held .3 of the way to the apex.


  6. I bet if you asked that person who didn’t time themselves how much their car weighs, or how much power it has, or the 0-60 time, they’d probably know. Data is important to everyone at some level.

    But ask a person to improve their own performance (education, exercise, weight loss, trail braking, etc.) and you’ll find reluctance no matter where you look.

    I used to be lazy with car data because of the technological hurdle (hardware and software), and only kept lap times. Now I’m a data junkie and feel like data analysis should be the basis of all high performance driving education.

    Sometimes people need to be shown the value before they covert. I was that way for sure.


    1. The fast track in high performance driving education is data + simulation + coaching. There is no better way to improve than having a coach examine your skills side-by-side with professional drivers. The data-free, real-world experience takes a heck of a lot longer. But it’s also really fun, and fun is a good reason for driving. However, if the driver wants to become really good, fun must eventually give way to work, and it will take extra time unlearning long-held bad habits.


  7. Ross Bentley did a Speed Secrets podcast on the Catalyst. There he answered many questions:
    No there is no OBD connection
    (Which is a shortcoming in my view – ultimately the driver has a few possible vehicle inputs, and graphing those can be really helpful).
    It sends you an immediate audible praise for new best turn speed or similar – that seems helpful.

    Lots of other info in that cast for those considering that device.


  8. I’d add that something like a garmin glo2 can make the phone apps much closer to being as useful as other sources for a lot less money still. $100 for 10hz gps and suddenly the split times and speeds mid corner are much much more accurate.


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