Gems from William Chen

SuperMiata is a really interesting racing series that does things a little differently. Chief among these is that the rules are designed to save money and the competitors must share information openly.

William Chen has written an amazing document called the Unofficial SuperMiata Racing Guide. The latest version is linked on the SuperMiata FaceBook page, but I’ve copied it below just in case it disappears.

unofficial_supermiata_30918

There’s so much critical info here from building to racing to towing. Surprisingly, among these 35 pages, there’s less than a page on actually driving. Let me sum what it says.

  • Intermediate drivers are too slow in corners
  • High intermediate drivers are slow in corner entries
  • You must heel-toe shift, and most beginners do it too soon
  • Messing up high speed corners is worse than low speed
  • When in doubt keep it in a higher gear
  • Trail brake: the slower you release the brake, the more oversteer you get
  • Don’t shuffle steer, leave the hands at 3 and 9

Let’s discuss these in a little more detail. I’ll rearrange them for convenience.

Steering

If you want to give the impression that you’re just learning how to play tennis, smash your first serve out of a forehand grip and patty-cake your second. You won’t have to tell anyone you suck, we can all see it. Similarly, if you want to look like you’re a novice racer, move your hands all over the steering wheel. You can get yourself out of this habit easily. Drive your street car everywhere with 2 hands on the wheel fixed at 9 and 3. Move them only briefly to shift, not to drink coffee.

Shifting

First off, shift less. Those corners where you’re not sure if it’s a 2nd or 3rd gear corner? Leave it in 3rd. How about those straights where you shift into 4th for 2 seconds? Just bounce it off the rev limiter. Why? The short answer is it’s faster. Shifting takes time. It also takes action, and that action can sometimes have negative consequences. You’ll be more consistent with fewer shifts and that leads to faster and safer laps overall.

The main problem I see with shifting is people bringing their bad street driving habits to the track. Shifting on the street is very different because the car speed is low and the engine is nowhere near redline. It doesn’t matter if you blip shift or not on the street. However, some people do, and they do it way too early. Early shifting causes two problems (1) the engine is over-revved and may get damaged (2) the engine is being used as a brake, which proportions too much bias to the rear (in RWD cars), which causes spins.

Braking

Racing requires trail-braking. Unfortunately, it’s a difficult skill to practice on the street. One reason for this is that the pedal feels firmer at race speeds than street speeds. Also, if you’re going fast enough that brake release causes oversteer, you’re driving illegally and stupidly. The only way to get better at this skill is with track time. Simulators work great if the brake pedal has a load cell. If you can find an autocross where you get to drive for more than 2 minutes per day, that can help.

Cornering

While it is true that messing up a high speed corner is more costly than a low speed corner, I see more variation in low speed corners. I think people are willing to be more aggressive in the safer low speed corners and this lack of consistency means more time is lost in low speed corners. Ideally, don’t fuck up any of your corners. They’re all important. Anyone can mash the throttle on the straight. It’s the corners that separate drivers.

I team up with a lot of drivers from complete noobs to SCCA regulars. So I see a lot of variation in talent and experience. Sometimes I find that experienced drivers have a lot to learn. Let’s look at some speed graphs. On the approach to T1, both the red and blue drivers get to approximately the same maximum speed. Both hit the brakes hard as indicated by the steep drop in speed. The blue line has a U shape whereas the red line has a V shape. The V shape indicates the driver has gone from full brake to full throttle quickly. If you look at where the bottom of the V is, it’s to the left of the bottom of the U. The red driver gets off brake and on throttle earlier. In slow, out fast, get to full throttle as early as possible. That should work, right? Sure, it gets you around the track, just not very quickly.

The blue driver is trail-braking. That’s why there’s a long gradual deceleration. The blue driver gets on throttle later, but maintains much more speed. Paradoxically, he’s using both less brake pads and less fuel to go faster.

Now let’s talk about T2. It’s a really long corner. Once again, the red driver brakes hard and makes the transition from brake to throttle sooner than the blue driver. The over-braking has slowed the car so much that it can’t get anywhere near the maximum corner speed. A lot of time is lost here.

So the solution is obvious, right? Just brake less and go faster in the corner entries. No, there is no just do anything here. If you take that attitude, you’ll probably run out of track at the exit and wreck the lap if not the car. Faster corner entries require trail-braking, and trail-braking is not a skill one applies simply by deciding to do it. There’s a phrase I’ve heard multiple times when people compare lap times and find themselves wanting. “They’re just driving harder”. Again, there’s no just anything. Certainly, driving faster requires some mental and physical commitment that goes beyond the casual. While you can bully your way out of being scared, you can’t bully your way to precision.

 

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