Cliff Notes

Ever since I started track driving, some 6 years ago, I’ve watched videos of people driving Thunderhill. It’s the closest track to me, and also my favorite (the West side is actually my favorite, but the East side is near the top of the list). In the beginning, I was just trying to learn the track. Later, I wanted to see how my lap times stacked up against other drivers. Today, I mainly watch to analyze driving technique.

When watching videos at Thunderhill, I like to focus on Turns 1-3. Each turn exposes specific driving errors and the entire sequence from the tower to the apex of T4 is under 40 seconds.

The video I have for you today features Cliff, a coach with Audi Club. His YouTube channel features a video from 6 years ago with HoD A and S stickers, so it looks like he got started track driving around the same time as me, or possibly earlier. Cliff is driving a 2015 Golf R with a shitload of upgrades. The Golf R has 292 hp stock, and the Stage 1 tune upgrades this to over 350 hp. The car also features Ohlins suspension, StopTech brakes, and 200TW rubber. The car is properly built for track duty. The description of the video says it’s his fastest lap of the weekend. The video doesn’t feature a lap timer on screen, but from the video timestamps I estimate 2:13.9. Seems like he should be able to go faster. So let’s dive in and see if we can figure out why.

Watch the video and then follow along below.

Some of the things I like about this video are the picture quality and overlays. It’s too bad the camera isn’t mounted inside the car, because it would be great to get an idea of what the driver is doing. Given that most overlays don’t show steering data, it’s useful to watch the driver’s hands to see if he’s fighting understeer or oversteer. I also like watching shifting technique. Oh well, not today.

One of the most useful tools for analyzing drivers is a speed trace. Ideally, your data acquisition system updates at 10 Hz or better. Phone-based apps like Harry’s Lap Timer or Track Addict typically record at only 1 Hz unless they are provided with an external antenna. Since I don’t have data for the lap in the video, I made my own by recording the speed of the car in 1 second intervals using the video timestamps. This provides a low-resolution speed trace (blue) very similar to what you would see from a phone app. I’ve also drawn a theoretical speed trace based on my own imagination, which I’ll discuss below.

Turn 1

In the first few seconds, you can see a major problem. The speed trace has a very rounded top. The car is coasting into the brake zone. I don’t actually subscribe to the phrase “you should always be on throttle or brakes” because people who hear that think it means 100% throttle or 100% brakes. And there are also instances when coasting is actually appropriate. But 2 whole seconds of coasting on the main straight is not one of those times. The amount of time lost is only a couple tenths, so it’s not that big a deal in terms of lap times. But it is a big deal in terms of technique. One should drive the car all the way to the brake zone.

The next thing to note is the deceleration. It’s not very steep. A car with 200 TW tires can decelerate at 1.0g. From observing the G-meter, the car never gets close. It spends most of the time at less than 0.5g. Technique-wise, I also brake more gently in high speed corners. My mindset is that I’m trying to set the corner speed at a specific value rather mash the pedal. But the braking here is just too timid. Looking ahead at other corners, he appears to always brake gently. The car and tires are capable of much more.

The final thing I want to point out is the location of the apex. This is the black arrow. The slowest part of a corner should be before the apex, not after. He’s coasting through the corner trying to hold speed. In the overused phrase “in slow, out fast”, the in slow happens before the apex and the out fast starts occurring a little before the apex. Here, the slow is still after the apex.

Turn 2

Like T1, there isn’t enough commitment to the brake pedal in timing or pressure. But the overall shape is pretty good. I see a lot of drivers mash their brake pedal and over-slow the car. Not so here. He’s using the brakes to set his speed, and then he drives through at the speed he set. Good.

Unfortunately, the mid-corner speed of T2 on 200TW tires is not 61-63 mph. Looking back at some of my data, I drive a couple mph faster in the pouring rain or when joking around on 185/60/14 Douglas Xtra-Trac II tires ($38 Walmart tires with a 420 treadwear rating). On a dry track with 200 TW tires, I’m around 72 mph. Why is he driving so far under the limit? Probably because he doesn’t like the feel or sound of sliding tires. Tires are supposed to slide a little on track. That’s where the optimum grip is. Driving a sliding car can be uncomfortable if you’re not used to it. The way to get used to it is to do it.

While T2 is a carousel with a constant radius, it is almost never the case that one should drive a constant radius. On a long corner like T2, you should use the first half for braking and the second half for accelerating. You may be slightly slower on the way out of the corner, but you gain a lot more by using the first half as part of your brake zone. Since there’s such a short straight from T2 to T3, it’s better to take this as a double apex rather than single.

Turn 3 and Turn 4

T3 is tricky because it’s off camber. There are lots lines through the corner, especially when racing wheel to wheel. Although Cliff’s overall grip level isn’t where it should be, the shape of the speed graph is just fine.

T4 is a typical 90, so the minimum speed should be before the apex. Here, like in T1, the minimum speed is actually after the apex. If you’ve got a car with 350 hp, you should use a driving line that optimizes the power of the vehicle. That means getting the braking and turning done early so you can throttle on a straight line. This is doubly true for FWD cars.

Rant on

It’s not really Cliff’s fault that he under-drives his tires. The E in the HPDE system is totally broken. If you haven’t read “Optimum Drive”, by Paul Gerrard, I highly recommend you do. He talks about how backwards the HPDE system is. I won’t repeat that here. Go get his book. Paul also says that if we want to solve a problem, we need to get to its root. The problem isn’t that Cliff coasts into brake zones or drives at 0.8g. The problem is that he’s not comfortable driving a sliding car. Fix that problem, and all the symptoms go away.

What’s the first lesson we usually teach new students? The racing line. As if that fucking matters. The line is a result of optimizing grip. Teach drivers to feel grip and the racing line will follow. The reverse isn’t true. Fuck the fucking racing line. I’d much rather have students drive in the middle of the track. There’s less chance they go off track and roll or hit something.

When drivers get comfortable just under the limit they reach a performance plateau that’s hard to break through. And the better they get, the harder it will be to unlearn later. Stability control, sticky tires, and 500 hp monsters all conspire against acquiring actual skill. But the students show up in Hellcats and Vipers, and I’m not getting in the right seat of one of those things without nannies.

If you really want to get better at driving, you have to have the right environment. Thunderhill in a 500 hp monster is not the right environment. The consequences of crashing at 130 mph are just too great. There’s a reason that the Kenny Roberts school is on dirt and why the Skip Barber school uses all season tires. Learning car control is safest when tires are slippery and speeds are low. Simulators are cheaper and safer still.

Rant off

On the other hand, not everyone needs to be a driving ace. Lots of people enjoy listening to music. Fewer people play music. Even fewer compose. If someone is having a great time driving around a track at 6 tenths, do they really need to turn it up to 8 or 10? As a coach, my #1 priority is safety. The #2 priority is to make sure the student is having a great time. For novices that probably means teaching them the racing line and “advanced techniques” like heel-toe shifting. As students graduate to intermediate and advanced, they need level-appropriate instruction. And just like with music or anything else, the lessons become less entertaining and more work. Drivers who didn’t start with a foundation of car control will take longer to reach whatever level they are trying to attain because they will have to unlearn a bunch of bad habits along the way. Who cares? It’s just time, and last I checked, time on track is a lot of fun.

Conflicted

Personally, I’m really conflicted about driving education. I firmly believe that car control is the only thing that matters, and if I ran a driving school, it would be mostly drills on a skid pad or simulator. However, I also believe that as long as drivers are safe, they should do whatever optimizes their fun. If I ran an HPDE organization, we’d do burnouts, drifts, jumps, and of course, the racing line.

Just 1 mph faster

I think most people who read this blog would like to go just a little bit quicker around a race track. In fact, that may be your New Year’s resolution in a couple weeks. Rather than trying to make a huge leap, like 5 seconds, focus on something more realistic, like averaging 1 mph faster. How much faster is that in terms of lap times? It depends on the car and track. For example, in the Global MX-5 Cup at Laguna Seca, lap times ran about 1:40 in the ND2 Cup car. That’s a nice round number because it’s 100 seconds. Anyway, it turns out that 1 mph amounts to about 1.3 seconds.

As a complete aside, if you’re wondering how much faster the ND2 MX-5 is compared to the ND1, both models are raced in the Global MX-5 Cup (in different classes of course), and the answer is about 2 sec at Laguna Seca. That’s a pretty significant gap, but there’s a lot more gap to be found among the drivers. The top ND1 driver runs about the same speed as the middle of the pack ND2 driver. The difference between the two cars is 26 hp. It’s kind of amazing that even among very good racers, some drivers are effectively 26 hp better than others. Among HPDE drivers, the gap can be huge.

So back to that 1 mph faster. How are you going to go about averaging 1 mph faster? It turns out there are two ways.

  1. Enter the corner with more speed
  2. Enter the corner with more yaw

1. More Speed

For most people, more entry speed is the low lying fruit. That’s because most people brake too much and enter the corner several mph too slow. To go 1 mph faster, just enter every corner 1 mph faster and everything should sort itself out, right?

Let’s take a look at some real data from my team at a Willow Springs race a couple years back. The driver on the red trace is braking way too much, on the order of 8-10 mph in T1 and T2. That results in a lower speed all the way to the next corner and a lot of time lost. You might think the red driver is a novice, or this isn’t his fastest lap, but he isn’t a novice and this is his fastest lap.

If you’re over-braking your corner entries, as do most drivers, then there’s certainly room to enter with more speed. But how can you determine if this is the case?

  • The best way is to compare your driving to someone in an identical car with identical setup and identical weather. That’s easy to do in the sim world, but hard elsewhere.
  • Have a coach or local hotshoe drive your car so you can compare data between drivers.
  • Compare your data to someone else driving a similar car. Perhaps you both have an GT86/FRS/BRZ.
  • Compare your data to someone else in a different car. If you’re on similar tires, your entry speeds should be similar.
  • Compare your data from different laps. You might find some laps you go in faster than others.

Perhaps you’ve noticed a theme here? You’re going to need some data acquisition gear and do some comparative telemetry analysis on the speed trace. Phone apps like Harry’s Lap Timer, RaceChrono, CMS Lap Timer, Track Addict, etc. work well enough. What if you can’t use a smartphone app? I’m not sure what world you’re living in where you’re worried about lap times and can’t use a phone app, but here’s my simplest advice.

  • If you can get to 100% throttle immediately, without any kind of maintenance throttle mid-corner, you probably entered too slowly.

One of the reasons people enter corners too slowly is that they’ve heard the phrase “in slow, out fast” too many times. Another reason is that going faster would scare the shit out of them. In any case, one of the problems of entering slowly is that being under the limit gives you an invitation to add a lot of throttle mid-corner. Here’s a pretty common sub-optimal control input sequence that’s very common among intermediate drivers.

  1. Mash brake pedal – leads to low entry speed
  2. Mash throttle – leads to mid-corner understeer
  3. Lift throttle – to prevent running out of room at the exit

One of the misconceptions of the intermediate driver is that they should mash the throttle mid-corner. That will get the car to rotate, right? Somewhere in their past the driver not only heard “in slow, out fast”, they also heard “loose is fast”. So they think mashing the throttle will get the car to loosen up. Spinning the rear tires isn’t the same as transferring weight to the front. Drifting greatly reduces the overall grip of the car. Transferring weight does not.

Too much speed

As you get better at optimizing your entry speed, you will eventually run into another problem: you can’t actually enter any faster. Let’s assume that 66 mph is the limit for a specific vehicle in a specific corner. What happens if you try to go 67 mph? The corner radius has to get bigger. The equation that relates speed, grip, and radius is: speed = sqrt(grip * radius). If you decide to enter a 66 mph corner at 67 mph, the radius of the corner will have to get larger to compensate because grip is a constant. In other words, you’ll fall off the track at the exit. If you don’t want that to happen, you’ll have to lift off throttle to tighten the radius and now you’ve basically done the corner backwards (in fast, out slow).

The intermediate level of driving is a mixture of too little and too much entry speed. In both cases, drivers are fighting understeer at the exit, but for different reasons. In either case, if you have to lift at the exit, you’re killing your lap time. The whole point of the typical late apex racing line is to optimize the power of the car in the second half of the corner. Lifting ruins that.

Even if you’re not lifting at the exit, you might still be in the “too much entry speed” category. Some drivers have enough discipline not to mash the throttle, so they don’t have to lift later. Instead, they spend a lot of time coasting in the mid-corner and are late on throttle. The time to add throttle is actually before the apex, but mid-corner coasters add throttle at or after the apex.

The high intermediate performance plateau

There is a very natural performance plateau associated with optimizing entry speed. Eventually you can’t go any faster and you learn the exact entry speed that maximizes every corner. If you accidentally enter 1 mph slow, you add a little extra throttle mid-corner, but not so much that you run out at the exit. If you accidentally enter 1 mph too fast, you coast a bit mid-corner, and end up a little late to throttle. This style of driving, where you modulate mid-corner speed with the throttle can be pretty fast and consistent. It isn’t actually the fastest or safest way around a track, however. Breaking out of this style of driving can be difficult, especially if you’re good at it. If you’re a racer whose been hard stuck 1-2% behind the front runners, this is probably the reason.

Brace yourselves, another tennis analogy is incoming…

One of the greatest tennis players of all time was Steffi Graf. She had a huge serve, killer forehand, tireless legs, and a consistent slice backhand. But no matter how good your slice backhand is, it is a liability against a serve-n-volley player who loves slow rising balls. In order for Steffi Graf to beat Martina Navratilova, she had to learn how to hit a topspin backhand. It’s a completely different stroke requiring changes as fundamental as how she held the racquet. Eventually she learned the stroke and the rivalry ended shortly thereafter. A similar situation existed with Ivan Lendl and John McEnroe. In case the analogy isn’t crystal clear, slice backhands are like intermediate driving. If you want to get to the advanced levels, you’ll have to learn how to rip a topspin backhand.

2. More yaw

The other way to lap 1 mph faster is to enter a corner with more yaw. There are two main advantages to this technique.

  • The front wheels do less steering
  • The drive wheels are pointed towards the exit sooner

Steering slows the car. The phrase “in slow, out fast” is not nearly as important as “the driver who steers less wins”. Having the drive wheels straight sooner leads to opening throttle sooner. Entering a corner with more yaw means less loss of speed and more gain of speed. It’s a win-win scenario. So why don’t more people do it?

  • Yaw leads to spinning

That’s reason enough. Spinning is dangerous. It wrecks cars, injures people, and gets drivers kicked off track. Lose-lose-lose. So why bother learning how to do it? Safety, paradoxically. A driver who can deal with yaw can deal with other adverse conditions such as rain, dirt, oil, and off track excursions.

How are you supposed to learn to drive with yaw when practice may endanger people or property? Thankfully there is sim racing. Your body can learn how to drive with yaw without breaking stuff. All you need is a sim rig and the motivation to unlearn your bad habits. But wait, what about that blog post a couple weeks ago where I was giving 12 reasons not to buy a sim rig? Those reasons are good reasons. But training your muscle memory to automatically correct for oversteer? That one positive is worth a few dozen negatives.

FWD vs. RWD rain: part 2 (thanks Paul)

I have to thank YSAR reader Paul for sending me down this path, because it’s been really fun. I truly appreciate feedback that makes me look critically at a problem. In this part 2, I do some testing in Assetto Corsa, and come away with some surprise.

Testing scenario

To do the fwd vs. rwd and dry vs. wet experiments, I had to choose a track, two cars, and two grip levels. I like to use Brands Hatch Indy and the NA Miata as a baseline. Sometimes I use the Street 90s tire and sometimes the Street tire. The Street 90s are a couple seconds slower. When you have the AI drive the car, both tires have the same lap times. I think it uses the default (Street 90s) tire. So that’s what I did too.

For the FWD car, I chose the Chevy Monza Classic 500EF. This model is a free download. One reason I chose it is because the dry lap times are very similar to the NA Miata when both cars are on their default tires.

For the wet grip, I reduced traction from the default 0.98 to 0.75. That figure is a little bit arbitrary, but I’ve seen various tables that show a reduction of about that much.

  • Track: Brands Hatch Indy
  • RWD: NA Miata
  • FWD: Chevy Monza
  • Dry – 0.98 grip
  • Wet – 0.75 grip

How to modify Assetto Corsa grip

There are three ways to modify the grip of cars in AC that I know of: run a server, change tires, change track surface. The easiest is the last, but for completeness, I’ll describe the other two first.

If you set up your own server, you can set the grip level of the track. This requires a separate program running as the server. That’s why I’m not recommending it. But on the plus side, it’s just one line of one file.

If the cars are developed in the legacy way, they have editable text files for individual components like tyres (yes, that’s spelled with a ‘y’ because AC uses the British English spelling rather than American English). Most cars these days have binary files that aren’t easily edited. Both the Miata and Monza use binary files. This is why I’m not recommending this way.

If you look in a track folder, you will find a surfaces.ini text file that you can edit. A track may have several surfaces. For example the Brands Hatch Indy file has 11 surfaces. Before you go editing this file, first make a backup copy so that you can restore it to its original configuration later. The grip levels of the various parts of the track range from 0.98 on asphalt to 0.6 for grass. To simulate rain, I set everything to 0.75 because I was lazy and didn’t want to multiply everything by 0.75. But that would be a better way I suppose. However, I planned on driving on the track, not grass or curbs.

AI driver

The first thing I wanted to test was how much the AI driver was affected by reduced traction. Here are the values.

  • RWD -7.31% loss
  • FWD -6.95% loss

There is more loss in RWD than FWD. To put it into the perspective of a typical lap, if your dry time is 2:00 minutes, your RWD wet time will be 2:08.78 and your FWD wet time will be 2:08.34. 0.43 seconds is pretty significant in a sprint race, but we’re not talking about 10 seconds here. It’s just a little time. However, this is the AI driving. What about a human?

Human driver

Move over AI, it’s time for Ian to step into the car.

  • RWD -9.06% loss
  • FWD -6.92% loss

That looks a bit more significant. Let’s put this into perspective of my Toyota Yaris at Thunderhill last May. My fast dry time was 3:43. If we multiply these 223 seconds by 1.0906 and 1.0692 we find that the difference between RWD and FWD is nearly 5 seconds. That’s pretty significant! Given that my Yaris is heavier, higher, and less powerful, than a Miata, the Miata has all the advantages on a dry day, but given some rain, the advantage just might tip in my direction.

Here are the graphs for the simulation experiments.

However, this is a human driving a simulator, what about in real life?

More data diving

Let’s look at the actual laps from the race. On a dry track, I was averaging about 3:50 in traffic. Bring on the rain and that drops to 4:20. So about 30 seconds. I had to make a lot of passes, and when I had a clean lap, I got down to 4:03, which is a loss of just 9%. Driving around slow cars in the rain really kills your lap time.

Some of the fast RWD cars I passed included the Miata of Eyesore and the Celica of Uncle Joe’s. Eyesore’s fast lap was 3:29 but in traffic it was typically 3:35-3:40. They dropped to 4:35-4:40 in the rain, a loss of 60 seconds. Uncle Joe’s fast lap was a 3:34 and it’s traffic laps were in the 3:40-3:45 range. In the wet, they dropped to 4:25-4:30, or about 45 seconds.

Two of the fast FWD cars I passed were the Integra of Big Test Icicles and the Neon of Neon Pope. The Integra went from 3:50 dry to 4:25 wet. The Neon was 3:45 and 4:30.

The race winners, Shake and Break (E30), were typically lapping at the same speed as Eyesore in the dry (3:35) but much faster in the wet (4:10).

Let’s take a look at the relative losses of these cars.

  • Yaris -13%
  • Celica -20%
  • Miata -28%
  • Integra -15%
  • Neon -20%
  • E30 -16%

Summary

Given equal lap times on a dry track, a FWD car definitely has an advantage over a RWD on a wet track. How much? I think it depends a lot on the skill of the drivers. At the high end, maybe 0.5 sec per lap. At my level, a couple seconds. At the “you can’t drive for shit in the rain” level, I think it’s less about which wheels are connected to the engine and more about the driver lacking the skill and confidence to maximize traction in the rain. Pedal mashers who over-brake and then hammer the throttle are the ones most severely affected. A Miata doesn’t normally spin when you stomp on the throttle. But it does in the rain, and if one’s driving style isn’t very nuanced, rain will be very unkind to your lap times. However, in a FWD car, stomping on the throttle may cause a bit of understeer, which is easily mitigated by lifting. FWD cars are more noob friendly. I’m not a noob, so I don’t see that FWD and RWD are that much different. But to someone not used to sliding their car around, RWD could be a major disadvantage.

I just watched the “you suck at racing in the rain” video again asking myself “where does the Yaris have an advantage?” The expectation is under acceleration. But that’s not where I’m catching people. It’s under braking. There is no FWD braking advantage. If you’re thinking it’s because my car is newer than the others and has ABS, that’s a good idea. However, you can hear the tires sliding in some corners when they lock up because my ABS has been broken for a while.

So to sum it all up, the reason for Yaris Rain Domination (YRD) is a little bit of FWD advantage and a shit-load of “most people suck at racing in the rain”.

Road & Track PCOTY

Road & Track just did their article on Performance Car of the Year and gave the award to the Hyundai Veloster N. At $30K, it was the least expensive car. Way to go Hyundai.

For the track test they had R&T editor Travis Okulski do the timed laps. He’s a “licensed club racer with no Thunderhill experience”. If you want to compare cars on track, and post numbers like 0.09 seconds difference between this and that, don’t you think it would be a good idea to get someone who knows the track and can post consistent times? There’s no way that 0.09 seconds, or 0.705g is meaningful when those numbers vary by huge margins from run to run.

How do I know the numbers varied from run to run? Because Travis Okulski sucks at Thunderhill West. His best time in a Mazda Miata RF was a blistering 1:34.64. I drive my Yaris faster than that. His best lateral Gs in T3 was in the Veloster N where he recorded an amazing 0.705g. Is that good? No, it’s terrible. Looking at some old data, I managed 0.95g on 195 width RS-3s, and that’s back when T3 had the brutal hump.

You know who could have done the driving? Ross Bentley. He was on the payroll and they had him do what? Drive vans around the track? There’s enough room on track to put multiple people on there at the same time. If you want to give readers an idea of what to expect, time all of the drivers.

Is the article good? I don’t know, I didn’t read the whole thing. I couldn’t get past the infographic showing times and telemetry.

Learning a new track: episode 1: Pacific Raceways

One of my favorite things to do in sim racing is preparing for a track I’ve never seen before. Not only is it fun to experience new challenges, but it also increases your corner vocabulary, which helps you get better at every track. Here’s how the process generally works.

  • Pick a track, usually one where I imagine I might drive one day
  • Drive the track blind, without any preparation
  • Do some online research: read track guides, watch videos
  • Drive more, working on specific goals inspired by the online research
  • Do some mental imagery, focusing on reference points
  • Drive more, trying to lap as fast as possible

I don’t always record telemetry in these sessions, but I thought it would be fun to do a post where I show how much I improve by learning the track over the course of a couple sessions on a lazy weekend.

When learning a new track, I usually drive a Miata or Formula trainer (e.g. FF, FV, Skip Barber). I’ve actually never driven a Formula car of any kind, but I think Formula trainers are great for exploring a track because they have unrivaled visibility, enough power to get into trouble, no nannies, and no downforce. It’s the purest form of driving. Maybe I should get one in real life. I do look longingly at Thunder Roadsters…

Session 1: Jumping in Blind

OK, time to choose a track: Pacific Raceways in Kent, Washington. Why? It’s on my Pacific North bucket list along with ORP and The Ridge. Lucky Dog has been hosting races there, so there’s a good chance I could race it in the upcoming year. I don’t know the track at all, except that I’ve seen some video clips of really awful wrecks there. I heard that they changed it a little to make it more safe, but I doubt the version I have in Assetto Corsa is that up-to-date.

The car: Russell Alexis Mk.14 Formula Ford. Like many cars in Assetto Corsa, you can download this free from Race Department. There’s also a link to send the author (Nicholas Murdoch) money via PayPal. I sent him $10. It’s as good a model as you’re likely to find in any game, and I really appreciate the author’s efforts. Certainly I will get at least $10 of enjoyment out of it, and $10 is tiny compared to real car stuff.

Driving without any preparation is somewhat suicidal. But in a good way. You very quickly figure out which corners will catch you unawares. Here’s a rundown of my lap times: 2:24, 1:57, 1:47, 1:51, 1:45, CRASH, 1:47, 1:43, 1:43, 1:42, 1:42, 1:40. There isn’t much point in reporting tenths at this point. I ran off track a few times early on, which accounts for some absurdly long lap times, and I had to restart once due to a horrific crash. In a blind session like this, I may do 10-15 laps.

There are some very tricky parts to this course! There aren’t any brake markers, so you have to look hard to find reference points. There are also places where the asphalt widens for other configurations (drag strip), making it difficult to figure out exactly where the track is going. This makes it difficult to plan the optimum line. There are also a few connected corners where compromises are necessary. Or are they? I need more time to experiment, but before that, I should hear what others have to say about the track.

Session 2: Track Guide

Why didn’t I start with track guides and videos? I find that until you drive a course, it’s hard to picture the specifics of each corner in your mind. While I would have gotten a little more out of Session 1 had I read some track guides first, I’ll get a lot more out of Session 2 having a mental movie of each corner in my mind. This isn’t a strategy I necessarily advocate when going to a real track for the first time! Do all the research you can before getting there and then review again after your track day.

I found the following videos helpful. The quality is pretty terrible, but the instruction is good. There aren’t any of the cone markers in the sim though, so those reference points aren’t there.

  • The main thing I took away from the videos was how simple T1 can be even without brake markers. If you’re on the left side of the track and gently turn in towards the end of the concrete wall, the track opens up for you.
  • Turn 2 is a huge decreasing radius corner, which is a hard corner to optimize. If you overslow the entry, you can’t make up for it by adding gas later as the radius pinches in. So you have to gradually bleed speed for a long time. That leads to a desire to hold as much speed as long as possible, but there’s a risk of going in too hot and washing out.
  • Turn 3a is really about finding a good braking marker. If you brake too late, and end up going off track, you could end up crossing the traffic on the other side. Not sure if there’s something to prevent this in real life. If you brake too early you end up in a weird situation where adding throttle seems like the right thing to do, but it isn’t.
  • Turn 3b is all about positioning yourself for a good exit. It’s a really long corner though, so the late apex is a long way around.
  • Turn 5a requires some early braking to scrub speed and then back on the throttle to stabilize the suspension. It’s possibly my favorite corner because it is so unusual.
  • Turn 5b is tighter and slower than it looks with a nasty curb at the apex. The best entry angle requires sacrificing the exit of 5a, and the next corner entry requires sacrificing the exit of 5b.
  • Turn 6 isn’t very exciting if you set up for it properly.
  • Turn 7 is tricky because the elevation robs you of vision and there aren’t good reference points. The track opens up absurdly wide due to the drag strip. What’s the line through here?
  • Turn 8 is puzzling to me. It feels like a decreasing radius corner but it doesn’t really look that way from the map. Like T7, there’s a heck of a lot of room and many potential lines. Not sure what is best.
  • Turn 9 isn’t very exciting in a low powered car, but I can imagine in a high powered car, you might have to sacrifice the exit of T8.
  • Turn 10 is just a mild bend. If you drive point-to-point, there’s a nice setup to T1.

Session 3: Corner Work

With a better idea of each corner in mind, I drove about 20 laps. The times were 1:48, 1:48, CRASH, 1:42, 1:39, 1:39, 1:39, 1:39, 1:38, 1:39, 1:38, 1:38, 1:43, 1:38, 1:38, 1:39, 1:38.6, 1:38.4, 1:38.3, 1:38.0, 1:38.0, 1:37.9. Let’s take a look at the specific areas of improvement between the two sessions and see how  picked up over 2 seconds.

  • On the 1:40 lap (red) I steer a lot and let off throttle in T1 at 2500′ feet. In my mind, this was one area I was doing really poorly, but it turned out to be only 0.25 sec.
  • I gain another 0.25 sec by managing my speed better in the decreasing radius T2.
  • Surprisingly, figuring out how to brake for 3b nets me 0.5 sec. (5000-5500′). That’s a lot of time in one braking zone. It is a weird braking zone though, because it’s downhill and turning.
  • The biggest gain is in the esses (7700-8400′), which isn’t what I was expecting. I didn’t focus on this in my offtrack studying, but the gain is nearly 1.5 seconds. Hustling the car before, during, and after 5a was the key. This one complex of corners amounted to the same gain as everything prior.
  • The fact that I didn’t see much improvement in T6-T9 suggests I might be able to find more time there.

Session 4: Mental Imagery

I fell asleep going through each corner in my head. I didn’t even make it 2 laps before I was asleep.

Session 5: Setting Flyers

The black trace is the same as the 1:37.9 above. The green represents the best in this session: 1:36.8. I was able to improve another second in two areas.

  • Better trail braking through T2 gained 0.4 sec.
  • A new understanding of how to connect T5 through T7 (7800-10000′). In this stretch, I was able to knock off 0.75 sec. by focusing on the compromises.

If I drove another 20 laps, I could iron out some of those losses and get into the low 1:36s. But for me to get into the 1:35s will require something new.

Details

If you want to compare your times to mine, drive with all nannies off, default weather, and default setup. Just in case they change the defaults at some point, here are the particulars:

  • Weather: 8:00, Mid-Clear, 26C, Optimum track surface
  • Traction Control: Factory (none)
  • Stability Control: Off
  • Mechanical Damage: 100%
  • Tyre Blankets: Off
  • ABS: Factory (none)
  • Fuel Consumption: On
  • Tyre Wear: 1x
  • Slipstream Effect: 1x
  • Gears: 13:38, 15:30, 16:23, 24:26, 10:31 (final)
  • Tyres: Formula Ford East, 16 psi all around
  • Fuel: 13 liters
  • Camber: -0.1 F, -0.2 R
  • Toe: 4 F, 12 R
  • Bump: 1200 F, 1950 R
  • Brake Bias: 52%
  • ARB: 15 F, 7 R
  • Height: 10 F, 20 R
  • Wheel Rate: 11 F, 22 R

As you can see, Formula Fords have a huge range of setup choices. Setting the car up for the clockwise direction and a gearbox that maximizes gear usage will certainly drop lap times. Tuning is something I do when I’m searching for tenths, and as you can see, over the course of a few sessions, lap times were improving by whole seconds. The low lying fruit is almost never setup.

Conclusions

Pacific Raceways is a really interesting track that appeals to me because of its mix of difficult braking zones and compromises. It’s not just a bunch of 90s that require precision. This is a thinking person’s track.

The most important corner

Which is the most important corner on the track? Every track has one, and it’s not always obvious. YSAR reader Eric recently shared some AiM Solo data with me that got me thinking about this. The event was last month at Oregon Raceway Park in the Lucky Dog Racing League. While I’ve never been to ORP, I have driven it in simulation (rFactor2) and it’s at the top of my bucket list due to its mixture of elevation, camber, and corner geometries.

Take a look at the track map below and try to figure out which corner is the most important one. While ORP can be driven in either direction, let’s consider the clockwise direction, which follows the black turn numbers from 1 to 16.

The common logic is that the most important corner is the one that leads onto the longest straight. By that logic, T16 and T2 appear to be pretty important. What if I told you that it’s actually T4? Why is a slow corner followed by a short straight the most important corner? After T5, the track goes uphill and is basically straight until T7. So really, what we have here is that T5 is the critical corner that precedes a long straight. T5 is also complicated by having a slightly blind entry. But regardless of the particulars about T5, there’s no way to take it optimally without throwing away the exit of T4. Which makes T4 the most important corner on the track (clockwise anyway).

One of the reasons I was eager to look at the telemetry data was because the team had Randy Pobst drive one stint. I’ve never examined the data from a pro driver, so I was eager to see what he’s doing differently than us amateurs. The difference between Randy and the team hotshoe was about 1 second, and the specifics of those differences are mostly about backing up the corner, a topic mentioned on YSAR plenty of times. When you look at lap times that are 3-5 seconds off, it’s some mix of the following:

  • Mashing brakes
  • Mashing throttle (causes understeer and a lift at the exit)
  • Coasting into brake zones
  • Crabbing into an early apex
  • Sub-optimal line through compromises (the main topic of this post)

Randy is a professional driver, and I don’t expect anyone on my team to match his lap times. I’d be over the moon if someone was within 1 second. Heck, 3-5 seconds off is fast enough on my team.

Third Gear No Brakes

Cross-posted from Mario’s Occam’s Racer. Editorial comments in red (at the end).

I don’t know a lot of car drills, and in fact I only do one: “Third gear no brakes.” Leave it in third gear (or fourth on a higher speed track) and don’t touch the brakes, that’s all there is to it. I learned this exercise from Keith Code back when I was a motorcycle journalist for Moto Euro. We did an article on the California Superbike School, and Keith made us do this drill for two sessions at Sears Point (Sonoma), in the rain.

Third-gear-no-brakes is a great way to focus on entry speed, and you absolutely have to use reference points. You will eventually scare the shit out of yourself, but after that, you’ll be surprised how fast you can go.

For example, here are two laps, the red is me, the black is my friend Jim. We are in the same car on the same tires, and he is .2 seconds faster than me. But if you look at the traces, he’s shifting and braking, while I’m staying in 3rd gear the whole time, never touching the brakes.

If you look at the time graph along the bottom, you can see I make up most of the time in the middle of the graph. This is the “knuckle”, a triple-apex corner. I have to shut off the throttle right at the end of the corner, and that long sloping line is me coasting downhill, waiting for the blind hairpin. At the same point, Jim’s trace looks like a mountain, with strong acceleration upwards and hard braking coming back down.

Jim isn’t a bad driver, he’s taken racing classes, and has raced wheel to wheel. He has strong inputs behind the wheel, and an aggressive driving style. But he slows down too much and my Miata doesn’t have a lot of power to overcome that.

This is what third-gear-no-brakes looks like from the cockpit. It’s not very exciting. I edited out the part where I went three wheels in the dirt!

One of the most common phrases you hear at the race track is “in slow, out fast”. I like making fun of this phrase because it does more harm than good. While I could mention that again here, I’m going to examine another common myth: “the most important corner is the one that leads onto the longest straight”. At Pineview Run, the “S Trap” leads onto the main straight. This is a super-slow left-right combination that is positioned at about 3600-4100 feet in the graph above. The black driver goes “in slow, out fast” and ends up with superior speed on the main straight. Yay. This leads to a couple tenths advantage at the end of the straight. Big fucking deal.

Now let’s look at something that turned out to be more important than the straight: the S Trap itself. Going into the S Trap, the black driver has built up a nice cushion (you can see this in the time graph as the big red hump). The reason for this is clear, the red driver wasn’t using any brakes on the approach and consequently has a huge speed disadvantage. From 3250-3750 the black driver is going a lot faster. But all the time gained in this 500 feet is lost in the next 200. Why? Because contrary to popular opinion, the slow parts of the track are critical. Going 1 mph slower in the slowest corner of the track is a lot more costly than 1 mph slower in the fastest corner. Why? Simple math. Going 99 mph in a 100 mph corner is only 1% off but going 49 mph in a 50 mph corner is 2% off. Given that slow corners tend to have long arcs, you can spend a lot of time going slowly.

The 3rd gear only exercise is one of the best things you can do on a practice day. With the focus on momentum rather than engine, your minimum corner speed will be higher. Like all drills, this isn’t the end of the story. You don’t want to drive like this all the time. If your minimum corner speed is too high, you will have to lift at the exit. Not only does this make your lap times longer, it’s also dangerous. But you can’t get to the end without getting through the middle, and 3rd gear only is an important part of the middle.