Ghosting the aliens: part 5, fast is fast

This is the last of the Ghosting the Aliens series of posts. Not to fear, we will return for more telemetry analysis in 2019.

Slow is smooth, smooth is fast

— said no alien ever

In this post, I’m going to argue that an overemphasis on “slow is smooth” results in “slow is slow”. If you truly want to be fast, there are some techniques that require you to move quickly. From the outside of the car, everything looks smooth, however. How does interior violence become external elegance? As we did the last couple weeks, let’s load up Alex Czerny’s fast lap in iSpeed. This time, let’s add the second fastest lap of the season, Riku Alatalo’s 1:39.842. Time for a closer look at alien anatomy.

Braking

Both Alex and Riku have similar braking profiles. They hit the brake pedal hard and fast. The release is slow, however. I think I’ve talked about “hard on, soft off” nearly every post in this series. It’s that important! Next time you’re on track, try to spend a little mental energy to examine your brake release. Do you get to maximum brake pressure quickly? More importantly, do you snap off the brake pedal or ease off? Hopefully you’re running telemetry and can look at the traces when you get home.

Clutch

There is only one way aliens use the clutch: fast. Look at the traces below. The clutch pedal is in and out instantaneously. If you find that you’re easing out the clutch, it’s because you didn’t match revs. The fix is pretty simple: wait. As you approach the corner, apply the brake pedal only. Wait. Wait some more.  Step on the clutch right before the shift.

Gearbox

There really isn’t a slow vs. fast argument in using the gearbox. If you’re sprint racing, you shift as quickly as possible and don’t care about abuse. If you’re endurance racing, you shift gently to ensure longevity. What’s interesting in the trace below is that these two aliens don’t agree on the best gear choice. Alex shifts briefly into 5th before T2 and Riku shifts briefly into 3rd in T10. If you’re looking for those extra tenths on track, your gear choice is probably the last thing to optimize.

Throttle

In a low powered car like a Miata, the throttle can often be used as an on/off switch. Note how many of the traces look rectangular. However, this is not true in the middle of the corner where the drivers are balancing weight to optimize grip. It would also not be true on a wet track.

Steering

The thing that separates aliens from the rest of the pack is that they can drive on the ragged edge while under complete control. The initial turn in to a corner is pretty gentle. At this time, their foot is still on the brake. The combination of steering and braking causes the back to lose traction and start rotating. This is intentional oversteer whose role is to point the car towards the exit. The car is now exhibiting excess yaw, and unless something is done about this, the car will spin. That something is a steering correction, and it is very, very quick. In the image below, I’ve put red dots where the steering wheel is moved with great speed. After the correction, the steering becomes slow again (unless another correction is required).

Aliens make steering corrections all the time. If you overlay multiple laps from the same driver, you’ll find that not all corrections are in the exact same place or have the same magnitude. The ragged edge isn’t always repeatable.

Let’s take a look at a couple videos featuring fast and slow corrections. The first video features me driving my brother’s Miata. If the video doesn’t queue up to the right spot, go to 1:30. Or just keep watching. I make steering corrections in a lot of corners.

Here’s what happens when you don’t make fast corrections…

Slow vs. Fast

So let’s review which parts of driving are slow and which parts are fast.

  • Brakes on is fast (assuming you’re traveling in a straight line)
  • Brakes off is slow
  • Clutch in is fast
  • Clutch out is fast if you’re rev-matching
  • Clutch out is slow if you’re not rev-matching
  • Throttle off is fast (usually, but not mid-corner)
  • Throttle on is fast after mid-corner balancing
  • Steering in is initially slow
  • Steering correction is fast
  • Steering out is slow

Final Thoughts

If you want to be a faster driver, telemetry analysis is a really useful tool. While comparing your laps to each other is helpful, the most gains occur when you compare your laps to someone faster. The cheapest way to go down this path is with a simulation rig. The telemetry is already built into the software and you’re not going to do any permanent damage along your bumpy performance driving education journey.

Telemetry: trail-braking

I’m relatively new to telemetry analysis, but I thought I’d share some of my experiences. The product I use is an Aim SoloDL. The companion software is called Race Studio Analysis. I don’t really like the software, but it’s better than several competing products. Rather than show you traces from my real racecar, I thought it might be more useful to use a simulator. That way you can call me names after you beat my lap times.

The simulator we’ll use for this is Assetto Corsa. Earlier this year, I posted on the state of the art in racing sims, and if you want to see a comparison of what’s out there, check that out. AC is one of the better sims, and possibly the best place to start. I’m using the Brands Hatch Indy track and the NA Miata. Just to get lap times out of the way, I usually lap in the 1:03-1:04 range. I’m sure someone who is more familiar with AC and Brands can take a couple seconds off that.

The point of this post today is to look at what trail-braking looks like from a squiggly line perspective. Trail-braking is a term that gets thrown around as an advanced cornering technique. It’s actually pretty simple: gradually release the brakes as you turn into a corner. This is in contrast to the more basic technique of separating pedal input from steering input. The reason it’s an advanced technique is that the rear of the car gets light under braking. So if you turn with the brakes on, the rear can rotate around and cause a spin. So why do it? I think most people will tell you that it’s because it saves a few tenths here and there. But the reason I do it is because I like getting tactile feedback from the steering wheel under braking. It helps me judge my corner entry speed.

So let’s say you just ran a few laps in Assetto Corsa. How do you get this into Race Studio Analysis? It turns out to be super simple. You’ll find the telemetry file in your Documents folder (open the Assetto Corsa folder there and then the aim folder inside that – there’s only one file ever in there). Race Studio Analysis can import this file. I don’t have enough time in this blog post to show you how to configure RSA, so let’s skip to the view of squiggly lines. I want to draw your attention to the parts marked A, B, and C.

The point marked A is Turn 1, which is a tricky downhill right-hander. The top row is speed, and you can see that the blue line has much more speed through corner, but the black line later catches up. That difference turned out to be 0.5 sec (bottom row). Look at the 3rd row (brake pressure). Do you see how the black line is on then off whereas the blue line tapers off? That little bit of braking while turning (4th row) is the sign of trail-braking. The 0.5 sec difference is more than usual, and had I carried more speed on the black line, the difference would have been half that.

Point B is more interesting, and you should look for it in the video below at about 1:53. The car is mostly straight as it goes through the apex. Do you see the dip in the steering angle of the blue line? With more weight on the front tires, you can turn more. What’s really important is the recovery after that. The car is steered in more aggressively while braking, and then counter-steered as the throttle is applied. The car on the black line can’t rotate as fast and can’t get to throttle as quickly. The result is about 0.4 sec. Point C is similar to B in that the car is at full throttle sooner because the car gets rotated earlier.

The cumulative effect of trail-braking a few corners turned out to be about 1.4 seconds. That’s probably a little bit of an exaggeration because I don’t normally separate my inputs, so it felt a little odd to me. But certainly there’s 0.5 seconds in the technique even on a very short track. More importantly, I think trail-braking makes you feel more connected to the car, and for me, that’s where the enjoyment is.

Chalk Talk: figure 8

YSAR isn’t just for crashes anymore! This week I’m introducing a new type of post: the Chalk Talk.

In California, the best way to learn track driving is with Hooked on Driving. What makes them so good? Like racing drivers, they are constantly trying to improve. As an HoD coach, I see first hand how much thought and care goes into their events. One recent improvement is that Hooked on Driving has teamed up with world-famous driving instructor Ross Bentley. Novice students now take his Speed Secrets Performance Driving 101 eCourse before coming to the track. So they already have a theoretical foundation in the basics of track driving.

Another recent change in the HoD novice curriculum was to cut a track session in favor of car control skills. While it may seem a disadvantage that students are getting less track time for their money (because they are), they are becoming better drivers because of it. Finding the limit of the car and driver on the skid pad is a lot safer than on track. Skid pad drills mean students also get instruction from more than one coach, which can be really helpful because every student has her own learning style and what clicks with one pair might not with another.

One of the car control skills you’ll find at HoD is the figure 8 drill. The basic idea is to drive a car around a skid pad in a figure 8 to experience oversteer and understeer. Extreme drifting doesn’t have much place on a race track, but it’s a very important skill to master because it helps refine your ability to manage weight transfer and recover from oversteer. While RWD cars are the champions of long, smoky drifts, AWD and FWD cars can also drift.

It’s hard for novices (or anyone really) to work on multiple skills at the same time, so I focus on just one skill per run. The last thing I say is the main point of the lesson. Here’s what I generally like to say to students the first 3 times through the drill.

  1. Nice car. Turn your traction control off and stay in 2nd gear. This drill requires a lot more turning than the track, so you won’t be able to fix your hands at 9 and 3. The point of this drill is to feel how the car responds at the limit. It’s much better doing that here at 20 mph than out on the track at 80 mph. You can creep up on the limit all day and never find it, so I want you to go over the limit. I want to hear your tires squealing.
  2. Keep your eyes up and look through the corner. It’s easier to control oversteer and understeer if your focus is farther away.  You should be looking out the side more than the front.
  3. On a scale of 1 to 10, how hard are you gripping the steering wheel? I want you to try 3. That’s like walking across the street holding hands with a child. Firm enough that they don’t get away but still gentle. The wheel is trying to talk to you, and if you are gripping too hard, you won’t be able to hear it.

The follow-up conversations will depend on how the student is performing. The three most common issues are (1) fear (2) patience (3) smoothness. Let’s address each one of these in turn.

Fear

Some students don’t like driving aggressively. They can’t bring themselves to accelerate, brake, or turn hard. Their tires don’t squeal. It’s hard to talk about oversteer, understeer, etc. when the car is being driven so tamely. A small part of me wants to say “stop being such a chicken shit”, but thankfully it’s a very small part. Students are there to learn and have fun. It’s no fun being yelled at. So I try to make it fun. I tell them “pretend you’re in a movie and you’re chasing bad guys”.

Patience

Highly aggressive drivers often suffer from understeer. They approach the corner fast, brake hard, turn hard, and hammer the throttle. And then they find themselves plowing through the corner unable to break the rear tires loose. The problem is that the weight of the car has shifted to the rear and the front has become so light that there is no traction left for turning. At this point, I describe trail-braking. Here’s what I say to drivers of RWD cars.

“Imagine the corner being split into 3 parts. The first part of the corner is taken with brakes on. Right now, I can see your brake lights are off before you turn into the corner. I want you to maintain a little brake pressure through the first part of the corner. This will keep weight on the front tires and prevent understeer. In the middle part, you’re transitioning your foot from the brake pedal to the throttle. Be patient here. In the last part, you hit the throttle and drift.”

At the track, I usually describe this with my hand making a semi-circle. I should probably bring a small white board. I would draw something like this.

figure8

Smoothness

Once a student is able to get their car to oversteer, I try to get them to smooth it out. Smooth isn’t just fast, it’s also safe (for both student and coach). Here are some of the typical conversations.

  • I want you to focus on what your tires sound like. There should be a constant squeal from entry to exit.
  • Nice drifting, but you’re going in like a lamb and out like a lion. I want you to be a lion the whole time. Go in faster.
  • Did you hear your tires squawk and then go silent? That’s because you used too much traction too early. Patience.
  • Try the drill one-handed. There is a lot more turning here than on track, and driving one handed prevents your arms from getting tangled. It will also help you lighten your grip on the wheel. But please don’t do this on track!
  • Try turning traction control back on, especially if you plan on using it on track.