De-synchronizing

If you haven’t read “Optimum Drive” by Paul F. Gerrard, I suggest you buy a copy for yourself and then buy more copies for your racing friends. My racing/driving library has over 30 books and Optimum Drive is my favorite. Conveniently, you can get it in Kindle and Audiobook formats as well as traditional print. I suggest listening to it in audio format on the way to and from the track. I’ve listened to it 3 times so far, and I’ve enjoyed it every time. In fact, I’m looking forward to the next listen. One of the my favorite phrases in the book is that “greatness lives in nuance, not simplicity”. We teach things in a simplified form to make the lessons easier to novices, but the subtleties end up mattering a lot than the simplification. One of the ways we simplify lessons is to synchronize 2 activities when really they should occur separately. He mentions the following instances.

  • Brake and downshift
  • Downshift blip and clutch application
  • Release brake and turn
  • Turn the wheel and turn your head
  • Accelerate immediately after brake release
  • Accelerate and unwind the wheel

Let’s go into a little more detail than Paul does at this point in the book.

Brake and downshift

Lots of drivers push both the brake and clutch pedals at the same time. I don’t think it’s a reaction to the phrase “in a spin, both feet in”, but rather, a bad habit entrenched from years of street driving. On the street, there’s no great penalty for downshifting immediately because the revs are pretty low. Let’s say you’re going 40 mph in 4th gear and downshift to 3rd. The engine will spin up from 2.5k to 3.5 (or something) as you feed the clutch out. No big deal. Downshifting early on a race track is a completely different story because your revs are always pretty high. Downshifting from 6k will cause your revs to spike higher than 6k, and may even go past red line. I’ve seen data traces where the highest RPM was in the braking zone rather than on any straight. That’s what happens when you synchronize braking and downshifting. In addition to the extra wear on the engine, you also change your brake bias by engine braking. In most cases, this will make your braking less efficient, not more. And if you’re in a RWD vehicle, the drag on the rear wheels could cause you to spin. What you’re supposed to do is brake first and downshift a little later. Let your speed drop before grabbing the shifter. If you’re in the habit of pushing both feet in, try to train yourself out of that. No good can come of it.

Downshift blip and clutch application

Long lost are the days when rev-matching was required on the street, so blips rarely make sense outside of a racetrack setting. When approaching a corner, one must coordinately brake, blip, and switch gears. Some people synchronize these too much by hitting all three pedals at the same time (left foot on clutch, right foot on brake and throttle). If you blip too early, you will feel obliged to shift early (see above). If you resist that urge, possibly because you don’t want to destroy your engine or your car, you’ll have to wait a bit for the speed to come down before feeding out the clutch. But the whole point of blip-shifting is to match road speed with enginespeed. If you’re going to let the engine spin down, what’s the point of blipping in the first place? It may have made you sound like a racer to people who don’t know jack about driving, but make no mistake, the people who know how to drive know the difference between heel-toe and shit-toe.

Release brake and turn

If you ever have me for a coach, you will see that the first lesson is brake release. Don’t snap off the brake pedal, release it slowly. The reason is because releasing the brake is sort of like accelerating. In both cases the weight of the vehicle shifts to the rear. When the front gets light, you get understeer. So if you snap off the brake and start turning, you will experience understeer. You may end up blaming the car, but it’s on you. The fix is to trail-brake. Keep a little brake pressure on while turning. Having weight on the front tires will make them more responsive when you turn the wheel.

Turn the wheel and turn your head

Turn your head first, of course. Novices are often focused on the hood of the car. Drivers should look where the car will go, not just where it’s currently going.

Accelerate immediately after brake release

If you can accelerate immediately after releasing the brake, you probably over-slowed the corner entry. If you’re driving at the limit, the moment you release the brake, you have maximum side loading. You don’t want to accelerate at this moment. You also don’t want to decelerate. What you want is maintenance throttle. I think this point is important enough to self-quote.

If you can get to full throttle immediately, without a period of maintenance throttle, you entered the corner too slowly.

Accelerate and unwind the wheel

You know that string analogy where there’s a string tied to your steering wheel and throttle? That’s what we’re talking about here. When the wheel is turned, no throttle. When the wheel is straight, full throttle. In between, there’s a mixture. But that’s an oversimplification. You should open the wheel in advance of opening the throttle. The advanced form of trail-braking, brake-turning, pretty much requires that timing.

Others

Gerrard mentions that these are just a few of the things we combine for simplicity. I wish he had listed more. I think that in addition to the things we combine for simplicity, there are things taught separately that should be combined. Trail-braking is a great example. Steering a FWD vehicle is another.

One thought on “De-synchronizing

  1. I agree this is my favorite racing book. I was also struck by that passage. I have been working on my downshift blip timing. I now aim to blip immediately before releasing the clutch, which seems better. I was blipping earlier, right after clutch depress, and it resulted in big blips with no real effect (except risk to my engine).

    Like

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