Big Lies #3: don’t coast

This is post #3 in a series of articles about some of the biggest lies in high performance driving. In this post, I’m going to address the myth that you should never coast on a race track. Another way of saying this is “you should always be on throttle or brake”.

Crabbing and coasting

There are two common behaviors you see in drivers who are early in their development: crabbing and coasting.

Crabbing is moving sideways on the way into a corner (like a crab). The driver sets up on the outside of the track, like they were told to by their coach (except me, see last article). But instead of turning in from the outside of the track, they start creeping in toward the middle of the track as they approach the braking zone. This decreases the radius of the corner for no good reasons. There are good reasons to set up mid-track, such as defending position, or driving a rain line, but crabbing is unintentionally throwing away speed or grip.

Lots of novices and low intermediates coast into brake zones. Instead of holding the throttle open all the way to the braking point, they let off the throttle and then coast a little before applying their brakes. Coasting a little before braking is a way to save tires and brakes when endurance racing. So it can be appropriate under specific circumstances. But during an HPDE session, there’s really no point.

Both crabbing and coasting are caused by a lack of confidence, or fear if you like. Both should go away in time as the driver gets used to the track and the car. That said, I’ve seen coaches who coast into brake zones (see the Cliff’s Notes post).

Coasting as an exercise

Two posts ago, I showed a speed trace of my brother doing a 3rd gear no brakes exercise. That’s a really great drill for several reasons.

  • You appreciate how much the car slows down from wind resistance. At 100 mph, taking your foot of the throttle makes a noticeable difference.
  • If you’re not allowed to use the brakes, you’ll naturally start to increase your entry speed. This is a good thing!
  • The more you do the drill, the better you will get at sensing your speed.
  • As you increase your entry speed, you’ll start to realize how much speed you scrub off by turning. This is especially true in slow corners because 3rd gear will be too tall and you’ll appreciate every mph lost.

As a training tool, intentional coasting is a great drill.

Always throttle or brake?

The problem with telling people they should always be on throttle or brake is that the phrase has no nuance. How much throttle? How much brake? Without knowing, I think drivers assume that means 100%. Why do I think this? Because most intermediate level drivers I coach alternately mash one pedal and then the other. But maximum speed requires maximum grip, and to attain maximum grip, you have to balance the vehicle. That happens at partial throttle and partial brake. And the utmost balancing happens between the two: i.e. coasting. In longer corners, there may be extended periods of partial pedal and in U-shaped corners where the 2 bends are are at an inconvenient distance, there may even be periods of coasting.

Being witty

With each one of these posts I’m trying to come up with a witty counter-phrase. The phases “never coast” and “always throttle or brake” just aren’t that catchy. Here’s my effort.

Coasting is like asymmetry: ugly when accidental, elegant when intended.

2 thoughts on “Big Lies #3: don’t coast

  1. I think you may be using the wrong term. I think most people define “coasting” as lifting completely off the throttle without applying brake, i.e., deceleration due to drag and engine braking. I believe you’re talking about what I call “speed maintenance throttle” – applying just enough gas to keep the car travelling at the same speed. With speed maintenance throttle, there is no longitudinal acceleration (in either direction), thus you can use 100% of the available tire grip for lateral acceleration. I haven’t driven it, but I’d imagine turns like the carousel at Road America would use this technique – you can use traditional trail braking on entry, but at some point you reach your minimum corner speed before you can apply *additional* throttle due the length of the corner, so you just maintain that corner speed until you can start accelerating.

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    1. Rightly observed. In a short corner, there is a moment between brake and throttle where both are at zero (unless you’re LFB). That is coasting, and generally the point of maximum longitudinal acceleration. But in a longer corner, when there is extended periods of maximum side loading, indeed, there isn’t coasting but maintenance throttle. Maintenance throttle is under-appreciated in driving. Not many people talk about it, but it’s really important.

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