The June 2014 issue of NASA’s Speed News e-zine is a great personal honor for me, with “Playing In Traffic” as the featured article on the cover. Speed News is a magazine by racers for racers, so it is both humbling and nerve wracking to be in a position to counsel such a large audience of experienced racers on a subject that everyone has extensive experience with. As you have probably guessed, the topic of my article is racing traffic strategy. I hope that what I had to say in that article presented a detail or two from a different perspective, or perhaps revealed a different way to approach the challenge than the reader had considered before. Take a look through the issue and let me know what you think in the comments.
Many thanks to Speed News for the honor, and for the opportunity.
Craig Breedlove, the first driver to set land speed records over 400, 500, and 600 mph, all in jet-powered cars that he designed and built himself, has a huge new land speed goal in his sights:
One Thousand miles per hour.
Traveling a mile in 3.6 seconds, making shock waves in the air at Mach 1.3.
This astonishing speed is well beyond the current absolute land speed record, held by England’s Andy Green and the Thrust SSC team led by another land speed legend, Richard Noble. The record today is 763.035 mph, and it set a permanent milestone as the first land speed record that is faster than the speed of sound. This record has stood since 1997 as the pinnacle of automotive speed: The Fastest Car in the World.
Why are we targeting 1,000 mph? Because that is what our competition has set as its goal since day 1, and we will run right with them. Noble, Green, and the key members of the Thrust team are mounting a new challenge on their own record with Bloodhound. The Bloodhound car is a superb technological tour-de-force, using a highly innovative new method of hybrid propulsion. The Bloodhound team has the best and brightest of minds, engineering techniques, and computational sophistication. With a 10+ year head start on us, they are naturally light years ahead in progress toward completing their car and beginning their test program. The way that their program is progressing is a shining example of English racing excellence. Brilliance is everywhere in that program.
What makes our approach better than Bloodhound’s? Simple.
Our approach is just like hot rodding has always been. Whatever the need is, find the simplest thing that is available and does that job well, and use that. This approach is a time honored and proven path to producing spectacular results quickly, and at a cost that is within the reach of normal people like us. For example, our engines are two 1950s era General Electric J79 afterburning turbojets, producing 17,835 lb of static thrust each. That is the propulsion system that you will find in an F-4 Phantom II. One of these engines powered each F-104 Starfighter, and four of them powered each B-58 Hustler. All 3 of those warbirds are spectacular performers, with proven top speeds faster than Mach 2! More than 17,000 J79 engines were manufactured over a span of 4 decades, in 11 countries. Availability is not a problem. With those engines, and our conservative estimate of air drag as Mach number changes, our performance simulation program shows that going fast is the easy part of the program. Of course the eternal quest in racing is finding ways to go faster, and we invite you to join us in our quest for the ultimate in speed on wheels. The Spirit of America lives on innovation, and we are constantly searching for the best possible ways to add speed. If you have an idea to help us go faster, let us know about it in the comments or contact us directly through the ThinkFast Engineering Contact link.
As fun as the speed quest is, our central focus is on doing the job safely. My mission is to keep our driver Mark Zweig alive. We are serious about speed, and we are really serious about safety. We will use the best materials, the best analysis techniques, the best simulation methods, the best testing and validation techniques, and a careful, methodical operational program to maximize our chances of success.
We will talk a lot more about Mark Zweig in upcoming posts, so here is the short and sweet story behind why he is our driver. He is an accomplished combat veteran pilot flying the F-16, he is a long-time military aircraft mechanic, he is a life long motorhead, he has a lengthy compilation of land speed records driving the world’s fastest Freightliner diesel truck, and he is instantly recognizable as one of the good guys of the world.
The Spirit of America program was announced today by Autoweek‘s Mark Vaughn. Here is a link to the article:
The About page at ThinkFastEngineering.com covers the highlights of my engineering career to date. My role as Director of Engineering for Spirit of America is the most exciting program that I have ever been involved in, and I am honored and humbled to be included in this extraordinarily talented, patriotic, positive, and heroic team. Great things come from great teams. I can see the progression of the entire program already, clear as day. It will be epic, and you can say that you have been a Spirit since the very first day. We invite you to join us in our quest to bring the absolute land speed record back to America.
As you have probably read in uncomfortably extensive detail here and here, I have inadvertently become an expert in re-learning how to drive a race car after a long time away from competition. Thanks to NASA‘s Speed News magazine, I have had the opportunity to share how to re-learn those driving lessons with a much wider audience. My article Back On Track covers the keys to returning to competition driving quickly and safely. If you think it has been too long for you to get behind the wheel again, check it out and decide for yourself if there is more fun to be had.
Until today, Think Fast – The Racer’s Why-To Guide to Winning was available exclusively in paperback form. Here is the link to the Kindle Edition of Think Fast. Everything in the print edition is in there – it’s the whole enchilada, but one that you can carry in your pocket. The dedicated web site for Think Fast has numerous excerpts to give you a sense of what it’s like. The unanimous positive feedback that I have received means that it must be one of the better racing books in print, and the Kindle Edition is yours for a lower price.
In my book Think Fast - The Racer’s Why-To Guide to Winning, I advised racing drivers to “Drive where the grip is, not where the line is.” This has turned out to be yet another example of “Do as I say, not as I do”, at least for one brief moment. Among the many photos that Kj Christopher took of my car at a recent practice day, one of them shows clear evidence of a massive understeer washout that was caused by driving through the dirt outside the clean line. Oops! For sure, there was a lot less grip out there. Even though I was driving a better theoretical line to set up for the next corner, the reality that most drivers weren’t made my theoretical best line slower for sure than the practical best line that was a car width or so to the inside.
This is a great example of my limited state of driving expertise caused by a long time away. It is also a great example of learning from objective evidence. You don’t need a fancy data system to learn lessons like this. I have actually learned more from photos and video of my driving from outside the car than from in-car video.
Many thanks to Kj for the photos.
Here is the key photo. The dust being kicked up by my right front tire makes it clear that I was driving on the dirty part of the pavement, where everyone else wasn’t.
Brett Becker, the editor of the National Auto Sport Association‘s Speed News magazine, has created a jewel. It is extremely rare for any magazine issue to earn a place on a serious racer’s bookshelf, and this one does. As soon as you flip through it, you will agree. Just click this link to get a digital copy for yourself, and more for all of your favorite track rats. ‘Tis the season, and it really is that good. Here is Brett’s concept for the year-in-review special issue in his own words:
We got to thinking what would better serve NASA members. How could we produce something that would be useful to readers over the winter months? We looked at all the stories about driver improvement published through the year. We also looked at the technical features, and found that there were a lot of “wrench ready” stories that offered step by step guidance on various aspects of car setup.
Wouldn’t it be great if we could compile all of them into one issue, so NASA members could reference them in one place rather than them trying to remember where they read that great tip about tire temperatures or that bit about tuning antiroll bars. We thought so too. So that’s what we did.
Welcome to Speed News’ inaugural “Ultimate Racecar Setup and Driver Instruction Manual”, your one-stop issue for the very best information for making you and your car go faster.
Here’s the link:
Flip the page and you are presented with a huge surprise. The table of contents is unlike any that you have ever seen, and it lays out what you are about to experience in five major categories that span the full spectrum of the racer’s quest. Whether your trips under the green flag number one or many hundred, there is a shocking array of genuinely useful information in there for you. 16 great articles in all categories fill this jewel issue.
And by the way, I wrote six of those articles.
The momentum is building, and it feels absolutely spectangular.
I’m finally taking my own advice. In my book Think Fast, I wrote “There is always more performance to be had from the driver than from the car.” Through the last two autocross practice days, I have focused on improving myself, and the results have shown very clearly that the zone between my ears is a very productive place to focus. This autocross practice day was very much a continuation of the process that I started during my last practice day, and it felt like it. I have now made 24 consecutive autocross runs without a major goof. Those of you who shagged all of the cones that I whomped a year ago will agree that I have stepped up to the next rung on the driver skill ladder. There are a lot of rungs left, and that’s OK with me. I have more progress to look forward to.
One of the biggest and earliest milestones to achieve during the process of improving your driving skill, oddly enough, is learning to ignore what your hands and feet are doing. It takes a lot of seat time, and absolute confidence in your car control abilities, your car, and the interfaces between man and machine to be able to tune out the fundamental mechanical actions of driving the car. The reason that this is important is that it frees a big chunk of your mental bandwidth so that you can direct it towards the next higher level of activity.
Now that I have stepped over that threshold, I have realized that my driving a year ago was most definitely below it. I can remember expending mental effort in planning out how far and how fast I would move the steering wheel, the shifter, and the pedals. Now I have absolutely no idea. My subconscious is handling the basic mechanics of driving.
I’m probably not all the way across that threshold because I’m very aware of every shift and I get consciously involved in catching slides, but I can tell a big difference in where my focus is while I’m in motion. Here is what that change in focus did for my performance:
That’s a cone-o-graph of my run times from the November 2, 2013 autocross practice day at Auto Club Speedway. Pretty, ain’t it? My one error is very obvious, but aside from that, this progression of run times is as good as I have ever done. My one error happened because I didn’t have the course fully memorized, and my line got behind the course entering a slalom. One area of my skill set that needs additional refinement is memorizing the whole course while I’m walking it. I was able to identify exactly where the problem was and correct it on the next run, and it stayed with me through the rest. For this event, my goal was to drive better every run, all the way through the finish of my last run. Here’s the video of that run. With that one exception, the cone-o-graph shows that I can claim Mission Accomplished.
So what is the “next higher level of activity” that I was able to focus on? Optimizing my line and speed to use all of the car’s grip limits for minimum run time. Balancing the combination of those variables, and optimizing that combination, is supremely difficult. Achieving some level of success in that endeavor is very satisfying. It’s the primary means of enjoyment that I’m able to get from a good day of competition driving. It has nothing to do with how my run times compare to anyone else’s, whether they are in my class or not. I realized long ago that the only person that I’m really ever competing with is myself. Having said that, I can now say that my level of driving performance, and the setup of the car, have both improved to the point that a new set of Hoosier R25B tires would not be a total waste of money.
Those of you who road race should also autocross. Autocrossing lets you develop all of those skills in a safe environment, to the point that line, speed, and grip also become subconscious activities. You absolutely need to develop that level of proficiency so that you can focus your brain power on risk management and traffic strategery. You will also learn how to get with the program on cold tires. The pack always spreads out pretty quickly after the start, so if you are going to do any passing, your best shot is during the start and the first lap, when you are in a tight pack and everyone’s tires are cold. You will also develop the ability to learn new tracks very quickly, as in a handful of laps instead of a handful of events at that track. Only after you have all of that fully under your control should you consider a radio system.
But wait, there’s more! I got to play starter for my work assignment, and I had a ball jumping around, waving the green flag with gusto, using creative gestures to guide each car to stop exactly at the start line, making eye contact and smiling with every driver, and generally making a fool of myself. Why not?
Back when I was autocrossing and racing all the time, it became apparent that I had lost a significant amount of driving skill after not driving for about 3 months. After a gap of any significant length, it would take several events before I was back up to my usual performance level. During the 4 year gap while I worked for Jim Hall’s Indycar team, I completely lost it all. My first several events after that were humbling. It took me about 1.5 years of getting my character built to get back up “on the step” in terms of competition driving ability. Those experiences convinced me that driving a race car is not at all like riding a bike: race driving skills fade quickly with disuse. Considering the fact that most professional race car drivers started in karts at age 5 and have been racing continuously since then, I think that no one starts out as a natural driver. We all have to work at it really hard, and we get worse rapidly when we don’t.
During the last couple of years, I have inadvertently learned a lot about re-learning how to drive after long stretches away from competitive driving. I had a 16 year gap, about 6 months of supremely embarrassing races, and a one year gap. The latest gap was caused by a new job that was 150 miles from home. Since I was away from my family during the week, I reserved the weekends for family-only stuff. Now that we are all moved in to a new house and the kids are in their new schools, I have some time to go play cars again.
I have spent a fair amount of time looking for good advice on how to speed up the process of re-learning competition driving, but came up with very little good stuff. In the process, I may have accidentally destroyed the fledgling web site raceruniversity.com by asking the question and getting no responses from the instructors there. A simple question like that should not have stressed the system to the point of collapse, but it got really quiet there after that. I’m surprised that there is so little good advice available on this topic, particularly since I can’t possibly be the only intermittent driver out there.
I finally realized that I should ask Paul Costas for advice on re-learning how to drive. He’s the Witchdoctor of Strategery for ThinkFast Lab, he’s a proven hot shoe, and he has a lot of experience as an HPDE instructor in Texas. And boy, did he ever come through with the goods. Here are some excerpts from our recent email exchange:
Paul: Advice? Tons.
This is all mental. Step into the car. Perform.
Neil: Dood! Love it. Very zen. This is getting printed out and living in my helmet bag, in the garage, and in the front of my setup note binder. If it would fit on the steering wheel, I would put it there too. So, while you are feeling philosophical about driver coaching, I have a question for you about over-driving vs. under-driving. We usually spend the vast majority of a lap providing smooth control inputs, and a small percentage of it making very rapid corrections to keep the car under control. What’s your opinion of the percentage of a lap that should be spent catching the car vs. making smooth control inputs? The Prost/Mears approach looks like 0% catching, but the Schumacher/Vettel approach definitely doesn’t.
Paul: The slower the speed, the faster the hands. The slower the speed the more the stopwatch can be influenced by aggressive moves and by pitching the car. On an initial run on cold tires overdriving the first bit will put heat into the edges of the tires quickly and get them gripping better, quicker. Once the tires are warm or on a second/third lap or a lap after a bit of cooldown, you may only need a slightly aggressive first corner or two and then work back to smoothness and ‘he who turns the steering wheel the least, wins’.
The inverse is true. The higher the speed the less tolerant the stopwatch will be of fast hands and the likelihood of the watch being kind to a pitch/catch maneuver is abysmal. Only in a last ditch keep-it-out-of-the-weeds move where the lap is likely screwed already. So I agree that the majority of a lap should be smooth inputs, and fast smooth inputs at slow speeds and slowish-smooth inputs at high speed.
For a % of lap guesstimate, it’ll come down to the lap or autocross course. The more that is low speed the more you’ve got to command the car. The more of the lap/course
that is high speed the more you’ll be herding the car and shepherding the car to go exactly where you want.
And insert tradeoffs and the ratios change again. If your car is really happy with low speed directional change you can of course be smooth. If your car is really happy at high speed but kinda fights you (worn fronts maybe?, bandaid setup?) on low speed then you’ve got to be ready to pitch it a bit in the low speed sections.
First lap of a race you need to be overdriving the car by a few percent regardless (assuming you’ve got some space and no cars up against you), at the very least for the first half to 3/4 a lap….must get heat in tires. Then you can back off a bit, be smooth and precise and make the tires last the distance. Mears was the smoothest person I’ve ever seen and I know he preferred setups that reflected that. Having seen Vettel in person now and watching F1 prac sessions 30′ from the track, they really REALLY rely on aero as they twist the nose WAY further/quicker than you think is possible and then the aero makes it stick and damn it if they dont make the corner and fly on through. Completely different animal than Scratcher or even Freddie as we dont have that downforce-parachute to save us.
The older I get the more I realize that the skippy school I took ages ago stressing how you get OFF the brakes is more important than how you get ON them is so true. I dont really care how I get the car slowed down to the right speed that allows the car attitude to be ready for turn in and power at the earliest moment and I’m still just caressing the brake pedal as I go for the gas.
In autocross driving Miss B4C (92 Camaro) I’ve had tons of folks come up to me and tell me that my brake lights are on and I’m on the gas at the same time. I’m constantly feeling for which tire can provide a bit more grip and using that. Also, transitioning from one to the other to ease the weight movement fore/aft as I turn the wheel to ensure the quickest sector time….I have two feet and I’ll use them at the same time. Ditto with road racing.
So any percentage number I give you will be weighted with the course type, the car setup and the condition of the tires….I’m sure the number would move quite a bit based on those factors. Driving style is obviously critical. We always hear of teammates running almost identical times with very different setups to suit their style.
Find your style. Find what you LIKE to have for feedback and what you are good at controlling and driving and set that up. Be aggressive out of the box and then bring it down a notch to precision when the tires heat up and you know that overdriving results in slop.
Neil: With these emails, you have just started writing an absolutely brilliant book. Or at least a massively huge and popular series of blog posts. I have spent a fair amount of time trying to find good advice on how to re-learn how to drive after a long gap. The advice you gave me today is a billion times more useful than anything else I have found. You have a gift. Use it.
I really hope that Paul takes up the challenge of spreading his driving advice, and his style of delivery, to a much wider audience than he has considered before. We can all benefit from it. I’m supremely thankful to be the first to benefit from the specific bits of Paul’s excellentness that you just read. And boy, did I ever benefit from it!
This nifty little image is a graph of the 12 run times that I got during a recent autocross test day driving Freddie in the California Speedway parking lot. Considering how bad my driving was a year ago, the clear progression towards an optimum that is apparent in these run times is proof of a dramatic improvement in my performance. Taking Paul’s advice to heart, I started slow and worked my way faster by a small amount each run. My natural tendency is to wildly over-drive, so it takes real effort to restrain myself a the wheel. Run #7 was slightly slower because the first 6 were in the morning session and the second 6 were in the afternoon, and I didn’t have the course fully memorized after that long. I drove just a bit more aggressively during each run, very much on purpose, including the last 2 which were apparently more aggressive than the optimum. I didn’t get close to spinning all day, and my cone count was much lower than usual. I think I only hit 2 in those 12 runs. I managed to exceed my modest expectations by a lot!
Here is the GPS-generated course map. The crosshair is at the start line and the path is color coded with speed. Blue is slow and red is fast. For reference, my top speed on that run was only 57 mph, so there wasn’t much of a straight anywhere. There were 3 places where I was up against the rev limiter in 2nd gear, but they were very brief. In cases like that, it’s usually faster not to shift up, then right back down, so I didn’t. With a Honda engine, I don’t have to worry about running it against the limiter.
Because this event wasn’t about going fast, I left the old dead Hoosier R35A road racing tires on Freddie that I ran at its last event. The grip was expectedly modest, but the car handled better than it ever has before. That’s partially because I changed the setup drastically from anything that I have run before. The setups that I had run in the past were all severely out to lunch, so I went with known good spring rates and took a huge leap of faith on damper adjustments. Based only on my recollection of how the car rode on rough pavement before, I adjusted the bump damping nearly full soft and the rebound damping nearly full stiff on both ends of the car. I also used the same tire pressures that I autocrossed with on my DB-1 almost 20 years ago.
That setup turned out to be very nice indeed! I wouldn’t call it balanced, but it understeered where I expected it to (in the slow stuff) and the rear stepped out enough times that the ratio of push to loose was near 50/50. It never really settled into a balanced drift, but that could be due to the nature of the course, my deliberate under-driving, or a still-non-optimum setup. For the first time ever, I was able to use the cockpit-adjustable front and rear anti-roll bars to try both different front/rear balance adjustments and different overall roll stiffness levels, and the handling responded just like I thought it should. Also for the first time ever, the balance was close enough to right that I was able to dial in the brake bias for autocross. It ended up 4.5 turns to the rear from where it started the day. That’s a really big adjustment. My DB-1 taught me that the optimum brake bias for autocross is much more rear-heavy than road racing, but on that car the difference was 2.5 turns. I still haven’t figured out why the brake bias is different for autocross and track events, but it most definitely is. If you can clue me in on the physics behind this, please do.
The nice behavior of the car and my semi-decent driving resulted in a somewhat reasonable looking ( to me ) picture:
That’s the friction circle plot for my best run. It’s an X-Y plot with lateral acceleration on the horizontal axis and longitudinal acceleration on the vertical axis. Forward acceleration is up, braking is down, and left and right lateral accelerations are left and right. The data logging rate is 10 Hz, so the data points are 0.1 second apart. The distance between data points indicates the rate of change of the combined acceleration vector of the car. The outer boundary of the data points is the maximum capability of the car in combined lateral and longitudinal acceleration.
A perfect driver would use all of the car’s grip capacity nearly all the time, so nearly all of the data points would be on the outer boundary. Professional racing drivers on road courses can get really close to that. The two things that I like about this plot are that roughly 3/4 of my data points are near the combined grip limit of the car, and that the shape of the grip boundary is close to round. That means that I was able to trail brake effectively and transition from cornering to accelerating smoothly, using all of the combined-vector grip that was available. In older posts such as this one, I have shown examples of my friction cirle plots that were distinctly heart shaped, indicating an inability to trail brake. Because about 1/4 of the data points were well inside the boundary, I was under-driving the car about 1/4 of the time. That leaves me with a lot of driving technique improvement to work on, and I will work on it as often as I can. I knew when I wasn’t maxing out the car, and why. It was a matter of not having the course and the line fully committed to memory. That is a skill that takes years to develop, but I’m confident that more seat time will slowly improve that particular weakness.
The grip boundary of the car is considerably less than I have seen with new tires. That’s not a surprise because the tires are old, and they are meant for road racing, so they never got warmed up to their design operating range during the brief autocross runs. The only track session that I have run on new tires showed max lateral at 1.88 g, compared to 1.40 g this time. That’s 34% less grip. New tires are awesome, but they are only awesome once. When I start buying new tires again, I will try to heat cycle each set correctly. I have never managed to do that before.
The IR tire temp sensors were on the car for this event, and they showed that I have more work to do in optimizing the cambers and pressures. The data clearly shows what I need to adjust, and which way, but not how much. So, more experimentation will allow me to home in on the optimums.
As you can tell, I was a happy guy all day long. Paul’s brilliant advice, and my ability to implement it somewhat skillfully, made my day.
My latest article for NASA‘s Speed News magazine is called Communcation Theory. It’s about how to measure and eliminate bump and roll steer from your suspension, and why it’s a good idea to do that. This is a complicated subject for a magazine article, so I applaud Brett Becker, the editor of Speed News, for letting me try to tackle the subject in a general-interest publication. If I succeeded in presenting the material in a way that is easy to understand, or if I didn’t, let me know in the comments. I appreciate all of the feedback that I get about these articles, and I look forward to working with Speed News for future opportunities to contribute to this excellent e-zine.
My article in this month’s issue of NASA‘s Speed News e-zine is an introduction to one of my favorite complicated subjects: damper tuning. I devoted a whole chapter of Think Fast to dampers. This article was a great opportunity to write an introduction to the subject for a wider audience. I covered some of the basic concepts and a couple of simple examples in the article. If reading the article gets you interested in learning more, you can get that and a whole lot more when you buy your very own copy of Think Fast – The Racer’s Why-To Guide to Winning.
Thanks to Speed News for the opportunity to contribute one more article for your enjoyment. I look forward to every new topic, and every new challenge to communicate complicated ideas clearly. Let me know what you think of the article in the comments!