Leapfraud

One of the things that I espouse is that when you go to the track, it should be to train. While it’s important to have fun, you should also spend some time working on your technique. So when YouTube suggested this video of cars doing a leapfrog passing drill, I nodded my head in approval. The video shows 4 cars taking turns passing each other as they work around Laguna Seca. The video is sped up 2x probably because it was sprinkling.

And then I started watching the video and the head nodding turned to head shaking. The drivers all seem to think that you’re supposed to crawl around the outside of the track and let the faster cars pass on the inside. I checked my library and the Internet to find the source of such wisdom. Finally I found the source. NOBODY FUCKING EVER. Apparently they’re trying to perfect this technique because they keep dive-bombing each other again and again. In some corners, they are driving around with their point-by hand still out the window. For crying out loud, there could be kids watching!

And what of the POV driver? The last time I saw this much pinching was at a shitting convention.

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.

Lemons thoughts

Some random thoughts about the last Lemons race.

Corner workers make mistakes

Going into the race, we knew that we had to minimize black flags. Everyone needs to, of course, but our car was much slower than anything else in B class and any black flag was going to put us out of contention. Sadly, we got two in the first stint. Neither one was earned. In Lemons rules, you’re allowed to pass after a yellow flag station if the mess is cleaned up. We did that and got flagged. That’s a judgement call on both sides, and given that, we should have been more careful. The second black flag was either for contact or for going 4 off. Neither of which happened, but the corner worker at T5 couldn’t see that easily.

Tuning

A couple weeks ago, the car worked great with 225 width RS4s on the front and 205 width RT615K+ on the back. I sort of destroyed one of the tires by overheating it and couldn’t run that set in the race. So I got some stickier front rubber in the form of 225 width 595 RS-RRs. I didn’t test that combination and it turned out that the team didn’t like it. Well, actually, they hated it. The team is used to an understeering car. When you get into trouble, you lift, and the front grips again. In an oversteering car, lifting only makes matters worse. As the car owner, it’s my job to provide a car that everyone can drive. Not only would the team be faster on average, they would also be safer and have more fun driving. We did eventually change the rears to get more grip and then later switched out the fronts for even less grip. Everyone but me liked it better.

Rain

Check the last post to see a video of me working through the field on a wet Sunday. I passed a hell of a lot of cars and in return was not passed. Here’s another video from our team a little later. It takes our driver a couple laps to acclimate to the wet conditions and then he proceeds to destroy most of the field.

 

The Yaris was one of the slowest and least sporty cars in the event. Why were we so much faster in the rain? Is it because we have extensive experience in the rain? I can’t speak for Danny, but I certainly don’t. I’ve only driven in the rain a handful of times. Maybe 3 hours total, and in other cars, not this one. So what’s the secret?

On my skills page, I used to have an ABC ranking system that asks the following simple question. When the car begins to slip, what do you do?

  • C drivers slow down
  • B drivers maintain speed
  • A drivers speed up

I think rain robs people of confidence. Lack of confidence can turn an A driver into a B driver or a B driver into a C driver. How does one gain confidence? Training. Like I said, I haven’t done much rain driving. So where do I get my training and the confidence that comes with it? Simulation, of course.

Lemons is changing

The C class has dwindled to just a few teams. And there used to be lots of teams sporting ridiculous themes. Our old MR2 was one of those silly cars and was just featured in the 24 Hours of Lemons Hella Sweet Car of the Week. Back then, our MR2 was put in B class with a couple penalty laps. Today, it would go into C class. I think Lemons has become a victim of its own success. Originally, Lemons was a parade/party poking fun at high performance cars. But over the years, racers have changed its culture. Part of that comes from competing series like Lucky Dog, ChampCar, AER, and WRL, where cars don’t have to be cheap and aren’t expected to have silly themes. The teams that do endurance racing tend to race all series. Now when you look over the Lemons grid you see sleek cars with $800 airfoils instead of cars shaped like boats with stuffed animals hanging out of them. While it’s true that I didn’t dress up my car or body with humorous artwork, I did bring a Toyota Yaris. But next time we’re going all in and “bringing back stupid”.

Stopwatch or it didn’t fucking happen

Probably like many of you, I sometimes watch car reviews on YouTube. I wish there was some way of determining ahead of time if the people reviewing the car were experts or poseurs. Here’s what one journalist says as he drives the Civic Si.

Chuck it into a corner like so… yeah, and you can feel that diff working up front, you can feel it pulling the car through the corner.

Now let your imagination fill in the scene… the driver approaches a tight corner at high speed… he brakes and throws the car in… the rear drifts around as the front tires dig the car out of the slide…

OK, time to click the link…

How embarrassing. The only thing he chucks into the corner is his credibility. He can feel the diff working… without any wheel spin? You fucking P-O-S-E-U-R. Apparently the 50k+ subscribers are tuning in for their sparkling personalities or handsome visages, because it’s certainly not the driving.

What about those reviews where the journalist gets out of the car for the track test? Hey Randy Pobst, can you take over? Pretty please. Drive the goddam car yourself. It’s literally part of your job description. Of course I understand why they do it. Professionals are more consistent. But the journalists should also post their lap times. If they’re 5 seconds off, I want to know that. It speaks to their credibility. Stopwatch or it didn’t fucking happen.

On the Physics of Racing

One of the first things I read on racing is a collection of articles called “The Physics of Racing” by Brian Beckman. This made a big impression on me because the author takes a very mathematical view of racing. That’s something I could sink my teeth into because I had more experience with math than performance driving. Then I got to the part where he went to a racing school at Sebring. He was more experienced than the novice racers but he was also older. All the students drove identical Panoz cars. He found that his old-fashioned straight-line braking left him 65 feet (about 0.5 seconds) behind the more modern students who were trail-braking. Then he drops this bomb.

A record time around the course in the Panoz school cars is 2 min 28 seconds. The students were doing 2:40 to 2:45. I believe I uncorked a 2:36 somewhere along the way, but my typical lap was 2:40 and the quicker guys pulled about 65 feet on me at the start-finish every lap, which I reckoned before to be worth half a second

I don’t want to know why he thinks he’s 0.5 seconds slower than a bunch of rookie racers. I want to know why his typical lap was 12 seconds off! Clearly there’s a more important lesson here than a little trail-braking. If the lap record is a 2:28, a 2:36 isn’t uncorking anything other than a bottle of shit. That said, he posted his lap times, and for that he should be commended. It puts things into perspective. He’s a guy who understands the theory of racing but has some trouble putting it into practice. That’s okay. Lots of people are in the same boat. Like me, or maybe you.

YSAR in 2019

As this is my first post of 2019, I thought I would say a few words on the future direction of YSAR. There are a lot of people who offer insight on performance driving. Most of them know their shit better than me. I’m not Ross Bentley or Peter Krause. So why tune into YSAR? I guess because you like your driving content with an eclectic mix of math, simulation, video, science, irreverence, and irrelevance. YSAR used to focus on crashes, but I think it has evolved into some kind of mental pit stop for the improving driver.

As we look forward to 2019, I’m eager to find out where this performance driving journey will take us. Frankly, I’m as much a passenger as a driver in this endeavor. Before we start, let’s agree to chuck the poseur bullshit into the corner. There’s no room for artifice where we’re going. There is room for incompetence though. Let’s find out where those 8-12 seconds went and fix that shit. Oh, and there’s also room for a metric ass-ton of swearing. This is you suck at racing, after all. The shit has, and always will be, fucking real. Or in more gentlemanly terms, I will always be honest with you. Whether it’s modeling vehicle dynamics, debunking driving myths, reviewing the latest gizmo, or recounting my latest driving adventure, I will present stuff as factually as possible. I give zero fucks about impressing professionals or companies, and won’t alter my content in an effort to impress or appease them.

Am I just going to ramble on this week or is there going to be any actual driving content? Okay, okay, let’s call bullshit on someone with more racing credentials than me.

The Euler Line

Do you subscribe to Speed Secrets Weekly? It’s a weekly newsletter delivered to your inbox. If not, you might consider it. Every Tuesday there’s new content from Ross Bentley and usually a guest writer. Professional drivers, engineers, and coaches contribute regularly. And also amateurs like me. I’ve written two articles for him in the past and just a few days ago I started a new 2-part article on why spinning is an important part of driver development. I won’t regurgitate those posts here but instead urge you to subscribe to SSW. It’s only $15 per year and makes every Tuesday just a little better.

One of the recent posts that got my attention was written by Randy Beikmann. It’s a theoretical post about the ideal driving line that compares the circular arc to an Euler spiral (pronounced “oiler”). Probably every book since Piero Taruffi’s 1958 classic, “The Technique of Motor Racing”, introduces the racing line as a circular arc. Nobody actually drives this arc. It’s used (1) to demonstrate the largest possible radius through a corner and (2) as a point of comparison to the typical late apex racing line. Here’s an awesome picture of the ideal line from that book.

One unrealistic thing about the circular arc is that one goes from straight wheels to turned wheels instantaneously. The author suggests that instead of turning the wheel suddenly, you should turn the wheel at a constant rate. Steer it in gradually, steer it out gradually. The path through the corner is not circular. It follows an arc called an Euler spiral, which is more gradual at the entrance and exit. The author goes one step further and shows through a Mathematica simulation that driving on the Euler arc is faster than a circular arc. In the diagram below, you can see the flatness of the blue line. That’s the constant speed of a circular arc. The Euler line has a lower minimum corner speed but makes up for it by getting to throttle sooner.

I greatly admire the elegance of the Euler spiral model, but it left me wondering “does anyone actually steer like this?” We can answer that pretty clearly by comparing theoretical and actual steering traces. TL;DR nobody drives the Euler line.

The black line below represents the steering angle of the Euler line: constant winding in followed by constant winding out. It’s shaped like a capital A. In reality, there are steering corrections. An idealized representation is shown by the green line, which looks like a capital M. The steering wheel is turned in a little, but then the back of the car rotates around (often from trail-braking). A steering correction (steering the opposite direction and back) puts the car back on line, and then the steering wheel is unwound towards the exit.

Here are some traces driven by the Assetto Corsa AI. Steering angle is the 3rd panel. As you can see, it doesn’t look like the letter A expected from an Euler line. The top of the peak is flattened and there’s often a spike in the middle representing the steering correction. At around 4000 feet the trace looks like the letter W, not V.

How about real drivers? Here are the “alien” steering traces I showed in part 5 of the Ghosting the Aliens series of posts. Where are the isosceles triangles? The steering wheel is rarely turned at a constant rate, and sometimes very quickly.

Here is me driving in simulation with 3 very different setups (blue understeer, red oversteer, green neutral). The middle panel is the steering angle. The understeer setup is the most similar to the Euler line, but it’s hardly symmetrical and there’s a steering correction late in the corner.

In theory, there’s no difference between theory and practice. In practice, there is.

So if nobody drives an Euler line, why is Randy Beikman wasting time writing and talking about it. It’s because it’s not a waste of time. It’s important to understand the theory behind racing. It’s even more important to understand where the practice differs from that theory. In the end, we want the theory to catch up to the practice. When that happens, we can take our speed beyond our current understanding. It takes time to model these things correctly. While less than perfect, I admire the work by Beikmann and his Euler model. Beautiful things can have flaws.

Rev-mashing: part 2 of 2

Are you rev-matching or rev-mashing? Let’s repeat the question from the end of last week. Where in the corner should you downshift and what are the consequences of shifting at the wrong point.

Red Zone

Lots of people start to downshift during threshold braking. As soon as they hit the brakes, they also depress the clutch and blip the throttle. There are several problems with this.

  • The car was already at high RPM and the blip just sent it even higher.
  • The car is currently going too fast to engage the lower gear.
    • If you shift to the lower gear immediately, you may destroy the engine by revving it past redline.
    • If you wait with the clutch depressed, the engine and transmission will spin down, negating any benefit of blipping the throttle. When you do engage the clutch, you’ll have to feed it in gradually to prevent locking up the tires. Congrats, you just ruined your brake bias and made the stopping distance longer. You’re also putting wear on the clutch.

Blip-shifting in the red zone is the worst possible place to shift.

Orange Zone

This is generally the best place to downshift. For really long decreasing radius corners, it’s too early though, as you’re still aggressively bleeding speed through half the corner.

Yellow Zone

In this trail-braking zone, your concentration should be on controlling the speed and angle of the car using a combination of brake pedal and steering wheel. It’s not a good time to take your hand off the wheel or dance on pedals.

Green Zone

This is the point of maximum lateral g-force. Your foot is making the transition from brake to throttle. In longer corners with extended trail-braking zones, this is a fine time to shift.

Blue Zone

You’re balancing throttle and steering as you pass the apex and track out to the exit. The over-rotation you initiated in trail-braking has to be wound out some in here. Probably better to keep both hands on the wheel.

Purple Zone

Although it seems way too late, shifting in the Purple zone is an ok place to shift. You’re not going to break any lap records doing it this way, but you’re also not going to do any damage to the car. If you drive through a corner in a gear that’s too high, it’s not that big a deal. If you’re balancing throttle and steering, as you should be, you don’t really need full power anyway. I don’t know anyone who actually downshifts after a corner. It would be like shooting free-throws underhanded: works okay, but looks too silly to be taken seriously.

Demonstrations

Here’s a popular YouTube video instructing how to heel-toe shift. The video overlays footwork and RPMs. Watch as he starts the downshift too early. The revs drop and feeds out the clutch gradually. If you have to release the clutch gradually, you’re not rev-matching, you’re engine-braking (or engine-breaking). One wonders how such a flawed example can have so many views.

Here’s the right way to do it. Notice how quickly the clutch is released as he blips each gear. You might also notice how he changes his hand position depending on which gear he’s selecting. It’s most noticeable for 2nd gear where he rotates his hand thumb-down. He’s not doing this to look cool, but I’m guessing somewhere there’s a ricer in a stanced Honda back-handing every fucking gear…

The 10 cent diamond

Overtaking another car is a great feeling. Passing 5 cars in one lap makes you feel like a driving ace. Passing 5 in one corner is a sign that something is out of the ordinary. Is there a yellow flag you haven’t seen? Is there something dangerous afoot? Is your car/driving just that much better than everyone else? If someone sells you a diamond for 10 cents, it’s probably not worth a dime. And if you just passed 5 cars, it’s might not be on your merits.

Watch below as the unfortunate driver learns a hard lesson about stomping on the throttle on a cold, damp track. Around here, we call such power-oversteer crashes Karma Supra. Video #2 is the rear view.

This YouTuber’s channel features some more entertaining moments (below). From watching their normal race videos, the team appears to have decent drivers and a well-sorted car (which sounds amazing). Sadly, shit happens all the time. Well, if it looks like shit and smells like shit, really, you don’t have to taste it before deciding whether or not to step in it. So be on the lookout for 10 cent diamonds and dog shit. They’re everywhere.

Stay the fuck home

Last weekend I was working at the Lemons race at Sonoma. I’ve stopped racing Lemons events at Sonoma because I can’t afford the risk to my car. There are lots of walls, the weather is often rainy, it’s always crowded, and there’s something in the air that makes people drive like ass idiots. Like take this one for example.

This guy has no business being on a race track. Stay the fuck home until you learn how to drive. The event is better off without you. OK, that’s not entirely true. The more the merrier. But honestly, it’s a lot of property damage and an opportunity for serious injury. I’m sure the driver will be much safer next time. It’s too bad the lesson had to be so expensive.

Speaking of the event, I was working at track-out giving drivers a final check before letting them on track. What exactly does this mean?

  1. Check that the car has the correct event sticker. Most people tech their cars properly, but some small fraction forget to put the sticker on, or put it somewhere we can’t see it. It also sometimes falls off in the middle of the race.
  2. Check the driver’s wristband. Some people forget to put it on or don’t realize you have to register the driver as well as tech the gear. I doubt many people are trying to sneak onto the track, but I have to check just in case.
  3. Check the helmet for tech sticker. This indicates the safety equipment went through tech inspection. That doesn’t mean the safety equipment is worn properly…
  4. Check the helmet strap and HANS tethers. Sometimes the helmet strap is loose or completely off. About 2% of drivers don’t have their HANS connected properly. I saw harnesses under HANS, incorrectly installed posts and one or zero tethers connected.
  5. Quick scan of other safety stuff. I’ve seen people wearing plasticky running shoes, helmets that don’t fit at all, drivers too tall for their cages, fire systems with the safety pin still in, drivers without gloves, etc.

If everything is in order, it takes about 10 seconds to check them out, but if I have to have a conversation it can take a while to sort out. We try to keep the traffic flowing on track as quickly as possible, which may mean shuttling cars with difficulties off to the side. It’s a fun way to spend the weekend. Not nearly as fun as driving though.

Bad driving tip #3: don’t check your mirrors

When two cars make contact, one of the drivers usually ends up saying “I had the line”. Well yes, there are rules that give one car priority over the other. As a very general rule, the first car that turns into the corner has right of way. Does that mean they can chop down on the trailing car? Yes and no. Yes, if you want to assert yourself as an aggressive driver, shutting the door on a competitor can be a smart move. The ensuing contact may be ruled in your favor, and that driver will probably avoid going door-to-door with you again. You win. However, there is an overarching rule that all cars deserve racing room, and if the officials say that you impinged too much on their space, the ruling may go against you. You lose. If you’re into amateur endurance racing, which is really the focus of this blog, then you lose even if you win because the other teams that didn’t get into these shenanigans all benefit whenever you pick up penalties.

One of the charms of amateur racing is the wide range of driver abilities. What looks like a driver aggressively shutting the door on another is often just lack of awareness. They had no idea the other car was there. The situation goes hand-in-hand with the bad driving tip #5, “always driving the school line”. Rank amateurs may believe that they are supposed to drive the line and let others work around them. But you can’t go outside-inside-outside if there’s a car on your door. You have to give the other drivers their racing room. Just like on the street, you have to check your mirrors before changing lanes.

In the first video below, a faster car blows by a slower car on the straight. They think they are in the clear, but they park it in the braking zone and then proceed to hit the slower car on the way to the apex.

In this next video, the slower lead car crosses the track in HPDE style and squishes the faster trailing car into a concrete barrier.

Here’s one more.

In just about every incident, there’s enough blame to be shared. In all three videos the car in front could easily have avoided the incident by checking their mirrors. The trailing drivers were the victims here, but had they realized how unaware the other drivers were, maybe they would have driven differently.

Bad driving tip #4: drive (too) nice

The road to Hell is paved with good intentions. The road to repair bills also. Your #1 job as a racecar driver is driving. While it’s a nice courtesy to signal other drivers that there is a danger ahead, such behavior requires you to remove one hand from the steering wheel and divert your attention from driving to signaling. In that moment your concentration shifts, bad stuff could happen.

In this first video, the driver sees the yellow flag and attempts to control the situation by alerting the drivers behind him. A fine gesture, and to be applauded. Unfortunately, he mishandles the steering wheel, which causes the car to drift to the left. The Volvo on his right gets spooked by other traffic (I think) and turns into him and what little space there was is now used up. This results in a multi-car crash. Alerting other drivers to the yellow flag ahead was a great idea, especially as the upcoming corner is blind and the flag station is hard to see. But keeping control of your own vehicle is job #1.

In this second video, the driver once again attempts to alert the cars around him of the upcoming yellow flag. But he’s so focused on waving that he runs into a stack of cars.

In this third video, the HPDE driver in the blue Z takes a very wide line while pointing-by 2 cars to the inside. Unfortunately, the driver is so focused on others that he doesn’t keep his car on track. The panic that ensues collects an innocent bystander.

In all 3 videos, the drivers are exhibiting a rare and treasured personality trait: kindness. But driving racecars on track is stupidly dangerous and requires a lot of attention. If you’re an expert, you can probably spare to split your attention between driving and other tasks. But if you’re not, focus on the driving as the #1 priority.

 

Bad driving tip #7: drive (too) fast

Sports cars these days have ludicrous amounts of power. For example, a 2017 M3 has 425 HP. Modern sports cars tame that power with stability control, traction control, and anti-lock brakes. You can generally turn off some of these nannies, but even if you don’t, you’re driving an amazing machine that can exceed 100 mph very quickly. At that speed, you can get badly injured. Crash tests are performed at 35mph, not 100. Yeah, your car isn’t designed to protect you at track speed. At 100 mph, you’re experiencing over 8 times the kinetic energy compared to 35 mph.

Race cars tend not to have any nannies or airbags. This makes them more dangerous to drive. Even with full cages and safety equipment, you wouldn’t want to crash at 100 mph. In the video below, the driver is in a race-prepped Porsche 911 (996) at Willow Springs. He runs off track in T2 at about 85-90 mph. When he hits the dirt wall, he’s probably going 75-80. The crash breaks 4 vertebrae. That looks like it really hurt.

911s are notoriously difficult to drive and Willow Springs is a particularly dangerous track when you leave the asphalt. Driving it hard enough for it to oversteer in the middle of the corner is what you’re supposed to do if you’re an A-level driver (see the Skill page linked above). But if you’re a B or C driver, going this fast could get you in a lot of trouble. Once the car begins to oversteer, the driver’s reactions are slow, uncoordinated, and panicked. He loses control of the steering wheel and becomes a silent witness to his own crash. Oversteer recovery should be engrained in muscle memory, capable of retrieval without thought. Heres’ an important tip: learn to drive a sliding car at lower speeds and in safer environments. Get a first-generation Miata and drive it on all-season tires. Stay away from high speeds and sticky rubber until you’ve learned how to slide a car from entry to exit.