When it’s not about the 10ths

Ross Bentley recently made a post on his FaceBook page about tenths of a second that got a lot of likes. If you’re not a regular consumer of Speed Secrets material, you can find a lot on his website, FaceBook group, and my favorite, the Speed Secrets Weekly newsletter. The first half of his FB post is shown below (which is recycled content from SSW).

  • If you were to enter the corner with half-a-MPH more speed, you would gain a tenth of a second.
  • If you used an additional few inches of track at the turn-in, apex, and exit of the corner, you’d gain a tenth of a second.
  • If you were to get to full throttle a car’s length earlier exiting a corner, you’d gain a tenth of a second.
  • If you compressed your brake zone approaching a corner by a couple of car’s lengths, you’d gain a tenth of a second.
  • If you began releasing the brakes a car’s length earlier (but not necessarily finished braking and taking your foot completely off the pedal any earlier – in fact, maybe you’d even keep a little bit of pressure on the brakes longer), you would carry a little more speed into the corner and still be able to get the car to turn in and follow the line you want – and you’d gain a tenth of a second.

If you’re looking at this list and thinking “yeah, I need to clean up my driving just a little to get those tenths”, you’re probably right. Yes, doing a few things a little better is surely worth a tenth here and there. But you’re also probably wrong. If you’re an amateur racer, the problem with your driving is not just a tenth here and there. You have bigger problems.

It’s not about the 10ths

In the racing I do, which is usually endurance racing or sim racing, what I’ve noticed is that what separates drivers isn’t one tenth of a second here and there. It’s whole seconds! I’ve talked about the distribution of performance before, and it isn’t a bell curve. It’s got a very long tail, and there’s a lot of dispersion. If you were to sample the drivers from a typical amateur endurance team, I bet you would find that the difference between the fastest and slowest drivers is 5-10 seconds. Is that because they all suck? I’m sure that’s what the real racers think. How about we look in on the one of the most tightly regulated classes (SCCA SRF3) at an event where you have to race all year just to gain entry (SCCA Runoffs). The difference between the first and last drivers during qualifying and racing in 2020 was over 10 seconds. These are experienced drivers in equal cars and they’re over 10 seconds apart.

Let’s forget about a tiny tenth of a second for a moment and consider how one loses whole bunches of seconds. What exactly are the faster drivers doing to make them faster. Alternatively, what exactly are the slower drivers doing that holds them back?

  • It’s not due to a 0.5 mph difference in entry speed or corner speed.
  • It’s not due to a few inches of track at the entry or exit.
  • It’s not due to a fraction of a second of full throttle.
  • It’s not due to a stronger commitment to threshold braking.
  • It’s not due to trail-braking or left-foot braking.
  • It’s not due to heel-toe shifting.
  • It’s not due to how one holds the steering wheel.
  • It’s not due to how much fuel is in the tank or the weight of the driver.

Here’s some data from some race or other at Thunderhill a while back. None of these drivers are bad drivers. They are veterans of amateur endurance racing who I will happily race with again. But as you can see from the speed traces, there’s a huge difference in how fast they are driving.

How to lose whole seconds

In my experience, there are two main problems to be solved.

  • If you enter a corner 10 mph too slow, you will lose whole seconds.
  • If you drive around a corner 5 mph too slow, you will lose whole seconds.

There are many reasons for being 5-10 mph off. One can’t simply tell a slower driver to enter a corner 10 mph faster or maintain 5 mph more corner speed. You can’t bluff or muscle your way into high performance driving. Those who try just end up crashing. We have to identify the root causes that lead to these behaviors, fix those root causes, and then get to to faster driving.

Root causes

Here’s what’s behind the 5-10 mph problems. These are sorted from most to least common. (Of course, this is the opinion of an amateur racer, so feel free to disagree).

  • Fear of sliding. If you back off every time the car starts sliding, your corner speeds will be way too slow. Racecars are supposed to slide. We’re not talking about oversteer, but all 4 wheels sliding as you navigate a corner.
  • Misunderstanding line. The racing line is much more complex than where to drive on a track. Each point on the line not only has a position, but also speed, yaw, and 3 axes of acceleration. Some drivers think that because they are at the right position, they must be driving correctly. One of the things that bothers me about coaching is that so much emphasis is on position. Hey, the racing line is the result of optimizing speed, yaw, and Gs, not the cause of them.
  • Misunderstanding aggression. If you think that you need to drive more aggressively, you’re wrong. You need to drive with more precision. Balancing a car on the edge of traction is a delicate process. One does not just drive harder. If you want to go really fast, there are times when you need to drive with more commitment, which does feel aggressive, but it’s not white-knuckled bravado you’re summoning, but flow.
  • Inability to estimate entry speed. If you can’t estimate your speed to within 1 mph of your actual speed, you won’t be able to enter corners at the correct speed. Since entering a corner too fast can end in disaster, you may be entering way too slow. One of the biggest challenges real racers face when they try a sim is the difficulty in estimating speed. This isn’t really a post about sim racing, but the solution for that is reference points.
  • Inability to estimate grip. If you can’t feel when your tires have optimal grip and when they’re losing grip, you will probably under-drive them severely to prevent yourself from going over the limit.
  • Misunderstanding oversteer. Drifting is awesome and phrases like loose is fast sound cool. But if you think that throttle-induced oversteer is the fast way around a track, you’re wrong. Oversteer should happen on deceleration, not acceleration.


So how does one address these root causes? Just like any other sport: a mixture of drills, coaching, reflection, and study with as much free time as you can muster, as much perseverance as your motivation will permit, and because it’s racing, a lot of money.

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