Apr 012014

Bob Pockrass of Sporting News  presented the results of a reader poll of NASCAR announcers.  By way of disclaimers, this wasn’t a scientific survey – it was a sample of people who feel strongly enough about NASCAR announcers to answer an on-line poll.  My analysis is of that poll data and doesn’t reflect my opinions about announcers and announcing.

The results were interesting, but I was having trouble getting my (admittedly warped) brain around the results.  They were presented in a bar chart with the number of ‘best liked’ and ‘least like’ votes.  I’ve reproduced it here, but make sure you look at the original article so they get their clicks!

Pockrass Poll


The order is ‘most liked’ on the left, with  Joy, Bestwick, McReynolds and Darrell Waltrip at the top.  But boy, there’s no correlation with the bars on the right, is there?  Ole’ DW also has the most ‘disliked’ votes of anyone.  I started thinking about how you might present this data in a different format to make it clearer.

Don’t let anyone tell you the most important things you learn in math and science classes are definitions and algebra.  It’s reading and interpreting data, charts and graphs.

Please don’t think this is a knock of any type against Bob – the man was covering races and writing multiple articles per day while I was sitting around watching movers load the truck.  I’m a data geek.  I can’t help myself around data.  Surely there’s a twelve step program somewhere for people like me, right?

I realizes this probably needed a two-dimensional plot, with the horizontal axis being “liked” and the vertical axis being “disliked”. It took me a couple tries.  I flipped the “liked” axis so that small numbers of likes were in the same quadrant as large numbers of dislikes, since those two ideas are similar.

I also set the axes so that they crossed at the mean value of each variable.  Above the horizontal line, the number of dislikes was more than the average of the entire poll.  To the right of the vertical axis, the number of likes was more than the average of the entire poll.


A couple things became apparent immediately from re-plotting the data.

First, DW is in a class of his own.  Yep, you already knew that, but here’s the proof.  You either love him or you hate him in a way that no other announcer shares.  I labeled that quadrant “Polarizing” because people have really, really strong feelings about him both ways.  The dislikes, though, did outnumber the likes.

The universally ‘Liked’ announcers are in the lower left-hand quadrant – they have few ‘dislike’ votes and lots of ‘like’ votes.  Joy, Bestwick, McReynolds and Jarrett fall into this quadrant, with Joy leading the pack having most ‘liked’ and least ‘disliked’ votes.

The ‘Disliked’ announcers are in the upper right-hand quadrant – they have predominantly ‘dislike’ votes and few ‘like’ votes.

Then we have the lower right-hand corner, which I tentatively labeled ‘Agnostic’, meaning that people didn’t feel very strongly about the announcers either way.

So there is it, for what it’s worth.  Another way of looking at numbers.

And to think I used to hate USA Today for using bubble charts!

Mar 272014


I know this isn’t a picture of California.  But it’s a picture out my window, which is why this is a sort of short post.

There seems to be a clear division between the people who are upset about the tires Goodyear brought to California and the people who aren’t upset about the tires Goodyear brought to California.

The people who had problems are upset.  The people who didn’t have problems aren’t upset.

Here are the facts:

  • Goodyear brought the same tire they brought in 2013 – the first year of the Gen-6 car, which featured weight reductions, higher speeds, and higher loads.  The same tires (D4522 on the left/D4408 on the right) were used in 2012.  There weren’t a lot of complaints after that race – in fact, those two races have been cited as some of the most exciting races at California ever.
  • NASCAR tweaked the aero package and the suspension setup rules between 2013 and 2014.  The biggest suspension change was the removal of the minimum front ride height. These were relatively small changes compared to the changeover to the Gen-6 car.
  • California continues to change as a track.  The seams between lanes are getting more pronounced.  The bumps down the backstretch are getting bigger.
  • The teams continue to improve their setups as they learn more and more about the Gen-6 car. They are moving closer and closer to the edge of stability in an effort to make their cars faster.

Goodyear looked at the changes and considered how they would affect the current tire. In the end, they opted not to change the tire.  I have no way of knowing how much notice Goodyear had of the suspensions/aero changes for 2014.  They start making Daytona tires in October of the previous year, so they need a minimum of 3-4 months advance notice.

The teams knew about all these changes, and knew that Goodyear was bringing the same tire.  Most teams likely started off with something close to their fastest setup from last year.  A number of the drivers mentioned they had to back off their setups from practice because they weren’t happy with tire wear. That’s part of setting up a car – taking into account changes from the last time you were at the track.

NASCAR is still looking into the issue, but their initial impression was that the teams were too aggressive with their set ups.  They cited very low tire pressures as one reason for the failures, many of which appeared to be sidewall related.  Goodyear recommends 20-22 psi in the left-side tires and apparently some teams were starting off at 11-14 psi.  (Most of the failures were on the left side.)

Teams have always started out with low pressure in the tires because tire pressure increases as the tires heat up.  If you put the pressure you’d like to have in the tires at the start, it would quickly get higher than you want it to.  So you start with a low pressure and let it build up.

The problem with very low pressures is that instead of the air in the tire supporting the car, the tire sidewall is supporting the car.  This puts a lot of stress on the tire and, given how punishing a full fuel run is on tires, the stress can, over time, lead to early tire failure.

This is a very common pattern with race car setups.  NASCAR makes changes, Goodyear tries to anticipate how the tires will behave under the likely setups.  Teams try setups, make changes and Goodyear tries to keep up with the changes.  I suspect the reason we’re seeing the problems this year and not last is that the teams have become more bold with their setups.

It’s a never-ending iterative process, with Goodyear trying to anticipate the effects of new setups, rules changes and track changes, and teams constantly pushing the envelope.

That’s the challenge, though.  How much are you willing to risk to get just a little more speed out of your car?

Mar 162014

I’m falling down totally on keeping up with this – all due to some major changes in life that I’ll clue you in on soon – and the fact that I need to learn to say ‘no’ when people ask me to speak, especially if it involves travel to the North in winter.

Mar 142014

Engineering is a constant battle of risk versus reward.  How much are you willing to challenge your equipment in order to gain speed?

Speed is at the heart of the new ‘knockout’ qualifying.  The new format has made Friday afternoons much more interesting; however, it also raised a new series of issues and challenges for NASCAR and the teams.

NASCAR wanted to limit the types of changes that can be made to the cars during the qualifying process.  One of their limitations is that the hood cannot be opened, which precluded the use of cool-down units.C&RCooldown

Without the cool-down units, teams were having their drivers run laps at extremely slow speeds to give the engine time to cool down. A number of drivers raised concerns about the safety of cars doing 40 mph on the same track as others running 180 mph.

NASCAR announced last Tuesday that teams would be able to use one cool-down unit under the following conditions:

  • One unit may be used
  • The unit must be connected through either the left- or right-side hood flap/cowl flap
  • The hood may not be opened
  • Generators may not be plugged in
  • No cool-down laps allowed

Cooling down the engine is critical to getting that fast lap. Andy Randoph, Engine Technical Director with Earnhardt Childress Racing Engines, tells me that an unrestricted Cup engine loses almost two horsepower for every 10° Fahrenheit of water temperature increase.  Cool engines are fast engines.

An engine cool-down unit is a big box (about 2 ft x 2ft x 3ft) with a reservoir for 12-15 gallons of water and (often) ice.  The cool-down unit is hooked up to the radiator system and pumps cold water through the engine cooling system.  An engine may be about 280 F when the driver pulls it off the track onto Pit Road. Most cool-down systems boast that they can cool an engine to 50 or 60 degrees Fahrenheit in about five minutes.

Cooling an engine from 280 °F to 200 °F represents a gain of sixteen horsepower.

With very few exceptions (i.e. water), heating a material causes it to expand.  Cooling it makes it contract.  We often model atomic bonds as having the atoms connected by springs.  The hotter the temperature, the more the atoms move. The result is that the material actually gets bigger when it gets warmer.

But different materials expand and contract at different rates. For example, metal changes size much faster than glass. Running  a glass jar with a metal lid under warm water makes the lid expand more than the glass and lets you remove the lid.

Cool-down units cool the engine quickly  and that opens up a lot of possible problems because the cooling doesn’t happen uniformly.  There are a lot of different types of materials in an engine.  For starters, the cylinder head is made of aluminum and the engine block of cast iron.   When you cool the engine quickly, the differences in contraction rates create relative motion at the head gasket interface – where the head and the block meet.  Fasteners that once were tight can loosen up.

A second concern is that it is very difficult to maintain water level when using a cool-down unit.  The motivation for not allowing teams to open the hood during qualifying is to limit the types of modifications they can make to the car.  You’d have to position an official on each car if you let teams open the hoods.  Teams are going to have to be careful in how they do the cool-down procedure to make sure that they leave the car with enough water in the radiator system.

I know Chad Knaus told Dave Moody that he didn’t expect any problems with using cool-down units. A key trait of crew chiefs is optimism.  Changing a tire should be a routine act as well, but how many times have teams lost races because of loose or missing lug nuts? There are going to be situations in which a team, having just been knocked out of the top 12 with two minutes left in the session, are going to rush to cool the engine down and make another lap – and do it too quickly and have engine problems later.

As Andy Randolph told me, this is a classic case of risk/reward.  How much are you willing to chance damaging the engine for the race in an attempt to secure a good qualifying spot?

Feb 282014

Repaving is the last possible remedy a track wants to use, but when potholes (see: Daytona) show up, there is no choice but to tear up the old asphalt and replace it with new, fresh blacktop.  In the last few years, Daytona, Phoenix, Michigan, Pocono and Kansas have all been repaved.

We hear a lot from race teams about their ‘notebooks’ – the collected wisdom and experience from prior experiences at a track.  When that track is repaved — or reconfigured — the notebook pretty much goes out the window .  They have to start over.

They’re not the only ones.  I had a chance to talk with Greg Stucker, Manager of Race Tire Sales for Goodyear as part of an article I was working on for a British publication called Race Cup Technology about the many challenges inherent to ensuring that the tires provided to the teams are safe and fast.

Goodyear doesn’t categorize tracks the way most of us do, with the superspeedways, mile-and-a-halfs, short tracks and road courses. They have to take into account not only length, but the track surface and the loads the tires experience.

Venue Groupings

Grouping Tracks
Group 1 Daytona, Talladega
Group 2 Charlotte, Chicago, Darlington, Homestead, Kansas, Las Vegas, Michigan, Texas
Group 3 Atlanta, California, Dover, Kentucky
Group 4 Bristol, Indy, Iowa, Phoenix, Pocono
Group 5 New Hampshire, Richmond, Gateway
Group 6 Martinsville
Group 7 Sonoma, Road America, Mid-Ohio, Ontario, Watkins Glen

This results in seven “venue groupings”, with superspeedways and road courses in their  own categories.  Martinsville, that unique concrete corner/asphalt straightaway hybrid also stands in a class by itself.  The remaining tracks are categorized into four groups.

Although Atlanta and Kansas have similar length and shape, they are in different groups. Atlanta’s surface is much older and rougher.  Speeds are higher.  That places different demands on the tire than a smooth, newly paved surface like Kansas.   Goodyear’s categories change almost yearly as tracks age and are repaved.  Kansas used to be in the same group as Atlanta prior to the former’s summer 2012 repave.

You wouldn’t think that Bristol, Iowa, Indy, Phoenix and Pocono had much in common, but as far as tires are concerned, they are all in the same group because of the combination of track surfaces and loads.

There’s another dimension to consider here:  time.  Michigan and Kansas  - two tracks in the same venue grouping – were paved within six months of each other.  Stucker points out that the surfaces aren’t aging the same way.  This is a combination of on-track activity, and the vagaries of weather – how extreme the temperature changes have been, how much moisture the tracks have sustained, etc.

Goodyear is starting a new program to record representative three-dimensional images of track surfaces as a function of time so that they can develop a better understanding of how track surfaces age.

The track-mapping project uses a technique called fringe projection.  Imagine that I create a pattern of alternating light and dark stripes, similar to the one in the upper right hand side of the graphic below.


I’m going to project that pattern onto a surface and use a camera to capture the reflection.  A perfectly smooth, regular surface will not distort the pattern; however, if there are any irregularities – bumps or voids for example, then the stripe pattern will be distorted.

By varying the pattern and the angle at which the pattern is projected and recorded, you can use some very fancy mathematics to work backward and determine the shape of the surface that’s responsible for the distorted reflection.

The picture below shows you an example of a stripe pattern and the effect of shining the stripe pattern onto a toy fish.


Goodyear’s project will produce a series of 1.5 by 2-inch samples that can display details as small as three micrometers  (about one ten-thousandth of an inch).   This is smaller than the diameter of a red blood cell and about a tenth to a thirtieth the diameter of a human hair.

This surface-mapping project will help clarify both the smaller year-to-year changes of track surfaces due to weather and use, but also will provide information on how major changes like whole-track resurfacing or reconfigurations affects the racing.

Stucker points out that track technology constantly changes.  You can’t compare the most recent repave of Daytona with the repave more than a decade ago.  One big difference is that the binder – the black sticky stuff that sticks the rocks together –  tends to be much denser than it used to be.  The denser binder prevents water penetration and is more durable, which should decrease how frequently the tracks have to be resurfaced; however, that increased density means that it takes a lot longer for the track to start showing signs of wear.

It’s a cool application of a new technology that is being applied to a large number of possible uses.  The “light” used for these measurements can be any type of light, including lasers, visible light and/or infrared or radio waves, depending on the particular data desired.  This technology is used in Microsoft’s Kinect camera, which is used on the XBox to translate a user’s motions onto a computer display.  That system uses infrared light. Other applications include 3D imaging of the mouth (for dental work), of vascular walls, for facial reconstruction, corrosion analysis and failure evaluation.


Jan 102014

CBSs 60 Minutes and Vanity Fair recently released the results of a poll that provided some surprising insights about how people watch sports – some of which might be relevant to the constant discussion of declining television ratings and attendance at races. The most interesting question in the survey (IMO) was asking people whether they prefer to watch their favorite sport in person at a live event or on television.


I found this sort of interesting – more people would rather watch an event on television than attend it in person.  But what I found even more interesting was that they broke out the responses by age.

The leftmost group of bars shows the same data from the pie chart above.  The next four sets break out four demographic groups:  18-34, 35-44, 45-54 and 55+


There’s a very clear monotonic (changing steadily in one direction) trend here:  The older you get, the more likely you are to watch your favorite sport at home than to attend an event in person.

That sort of flies in the face of what one might thing:  That the core (aging) fan base are the ones who make it to the races.  Actually, we’re more likely to lose these folks the longer they’re fans.   The good news is that the young people we keep talking about needing to attract are more interested in heading to the track than their older counterparts.


NASCAR has made some significant changes and hinted recently that there are more to come.  They’re listening to the teams, the media and the fans more than I suspect they every have before.

The prime topic of discussion on blogs and radio is people calling for change or railing against it.

Another thing that happens as people get older is that they become more resistant to change.  You get comfortable with the things you know.  Most research indicates that you’re most open to change in your twenties, and become progressively less so, in part due to the fact that it becomes harder to change.  It becomes much harder to change careers once you have a family to support, for example.

I’ve got a rather different take on ‘changes’ that could be made to attract more people to the sport.  I would focus on making the sport more appreciated and accessible and less on tinkering with the racing.

When I speak at a university or high school, I always get people who come up to me after my talk, usually a little embarrassed, who say something like “I didn’t realize NASCAR was so interesting.”  Or complicated.  Or challenging.   For most people, it’s cars running in circles for hours.

Coming to NASCAR as a non-sports fan (and with no motorsports in my background), I had no idea how interesting it was either.   This all jelled this week when I read the comments Joseph Shelton (@That SheltonGuy) made about The Physics of NASCAR in his Bleacher Report summary of books NASCAR fans should read during the off-season.  I thanked him for mentioning my book and he tweeted what I think is a key point:

Your book is proof as to why @NASCAR should be taken more seriously than it is.  A lot more goes into it than thought.

While some motorsports fans denigrate NASCAR for being low-tech, NASCAR is incredibly high-tech compared to throwing a ball back and forth.  Much of magic of this sport is invisible.  You can’t see friction, you can’t see a tire heating up or wearing… not like you can see a running back zigging and zagging.  Getting a real appreciation for the strategy, the need for a zillion things to all work at the same time, and even for how absolutely difficult it is to drive a car on the edge of traction is hard – I think it’s a barrier for many people to become NASCAR fans.

So perhaps what we need is not so much changing the racing, but changing the accessibility of the racing.   This is where second-screen experiences have huge potential for helping people appreciate the sport.  I watch twitter during races along with the television and/or radio.  But I’d really like more data.  I want to see average lap times and be able to track them as a function of time during a race.  I want to be able to access history and see, for example, a graph that shows how Jimmie Johnson has historically finished when he starts in the rear of the field at that particular track.  I want a track map I can pull up at any time that includes elevation changes and maybe a drive along so I can appreciate what it looks like from inside the car.  (And trust me, Road America looks so much more awesome from inside a car than it does from the stands!)

The newbie fan might like an interactive glossary using something like blippar, where they could get real-time definitions and maybe even short video-taped explanations of specific terminology.  (The idea of a “loose car” can be baffling to the new fan.)  The second screen offers the option of customizing the experience for each fan.


Off my soapbox  now.  There was one more aspect of the CBS 60 Minutes/Vanity Fair poll I found interesting.  The question was “Which Sport has  the Highest Percentage of Jerks?”


And I think I’ll let that one speak for itself…

Dec 152013

It’s got to be a little frustrating that there are less than 90 days left before the start of the 2014 season and the rules package for the car isn’t set.  Teams hope for a little more clarity following the open test at Charlotte Motor Speedway Monday.

NASCAR’s put a lot on the table – everything from suspension changes (like static ride height) to aerodynamic modifications to the spoiler and splitter.  On the positive side, teams are very happy at how inclusive NASCAR is being with their changes – they’re listening to input from the teams, sharing their thinking processes about the changes and their conclusions from the tests.

One of the overriding themes that keeps coming back is a desire to slow down the cars to improve the racing.  Let’s look at how that works.

There are always some people obsessed with numbers, but we all know that some of the fastest tracks – the 1.5-mile ovals – have struggled to produce competitive racing.  One of the major problems is the aerodynamics of the cars.  Drivers complain that they “can’t pass” because of “aeropush”.

Slower?  But This is Racing!

It is great fun to stand near the fence and have to hang on when 43 cars come whizzing by at 200 mph; however, I bet you wouldn’t notice much of a difference if they were “only” going 190 mph.  Racing is about relative speed – how fast one car is going relative to the other car.  It doesn’t matter if car 1 is going 200 mph and car two is going 199 mph, or if car 1 is going 190 mph and car 2 is going 189 mph.  The difference is speed determines who leads — and who wins.

Sure, it takes your breath away when you realize that a stock car going 190 mph travels about the length of a football field a second; however, do you want speed or do you want passing?  There is an old saying:

An aircraft is a series of compromises flying in close formation

So is a racecar.  NASCAR’s job is to figure out which compromises to make, with the goal being exciting racing.  So everyone calling into radio shows saying they want both really fast cars and a lot of passing, just stop now.

Some have complained that slowing the down the cars is just going to make the racing more like that in the Nationwide series.  But it isn’t just a question of speed – it’s a question of where that speed comes from and the balance between mechanical grip and aerodynamic grip.

Getting a Grip

A tire’s grip depends on two things:  how well the rubber sticks to the road and how much force is pushing the tire into the track.  The more grip, the faster you can go.

The first element – how well the tire sticks to the track – is a property of the tire.  Teams are prohibited from chemically treating or physically changing the tires.  That means the big variable they have to play with is the force pushing the tire into the track.

Imagine I give you a tire and ask you to pull it.  Not so hard.  Now I have Tony Stewart sit on top of the tire.  It’s going to be a little harder to pull now, right?  That’s because the extra weight pushing down on the tire gives the tire more grip and makes it harder to move.

A caveat:  The weight pushing down on each of the four tires isn’t the same because of the initial weight distribution of the car and load transfer (the shift of the body weight during braking, turning and accelerating).  To keep this straightforward, I’m not going to to worry about downforce distribution, just talk in terms of total downforce.

When it comes to downforce, more is better.

Mechanical Grip

The car’s weight pushes the tires into the track.  This type of grip is called mechanical grip.

A heavy car has more grip just because it’s pushing down on the tires harder; however, you need more force to accelerate a heavy car.  A typical weight for a Gen-6 car is 3480 lbs with driver (3300 lb minimum weight, 180-lb driver).  You can change the mechanical grip of each tire by adjusting the suspension and tire parameters such as camber and pressure;however, every car has about the same amount of weight to distribute.

Aero Grip

If cars depended only on mechanical grip, they wouldn’t go very fast.  If we raced in a vacuum, it would be pretty boring.

Luckily, we have air to help with grip.  As a car travels, it encounters billions and billions of air molecules.  Those molecules bounce off the car’s surface, exerting forces.  Each air molecule exerts a small force, but there are a heck of a lot of air molecules.

The forces have different names depending on the direction they push.  If the air molecules are pushing opposite the direction the car is moving, we call that drag.  If they are pushing down on the car, we call that force ‘aerodynamic downforce’.

Aero_DefinitionsHere’s the big difference.  A car’s weight doesn’t change when you speed up or slow down.  Aerodynamic downforce does.

Aerodynamic downforce is quadratic:  it changes like the square of the speed.  If the car goes twice as fast, it gets four times more aerodynamic downforce.  In the graph below, the blue line shows the mechanical grip and the purple line shows how the aerodynamic grip changes with speed.  The numbers are typical numbers for a Sprint Cup car in race trim at a 1.5 mile track.





This is one reason driving a racecar is so challenging.  At a track like Texas, you might come into a corner doing 200 mph and reach 180 mph in the center of the corner.  You’ve lost almost 440 lbs of grip just going through that part of the corner.

Here’s the really important difference between mechanical grip and aerodynamic grip:  Being in another car’s wake doesn’t change your mechanical grip, but boy does it change your aerodynamic grip.   The aerodynamic downforce is generated by the air flowing over the surface of the car.  When you get close to another car, that changes how the air flows over your car and thus changes your grip.

Aerogrip and Speed

When you’re running around Bristol doing 90 mph about 12 percent of your total downforce is due to aerodynamic downforce -the rest is due to mechanical downforce.   When you talk about 1.5 mile tracks, where speeds hit 205 mph, now about 40 percent of your total downforce comes from aerodynamics.  This gives the car in the lead an incredible advantage because the lead car can harness the aerodynamic downforce and the other cars can’t.

PercentAeroforcevsSpeedThe faster you run, the more dependent you are on the aerodynamic downforce.  That’s why the problem is greater at the high-speed 1.5 mile tracks.


There are a lot of ways to slow down the cars and NASCAR seems open to investigating just about all of them – with the caveats that any solution can’t introduce safety issues or be prohibitively expensive.

  • Decreasing engine power can be done quickly using tapered spacers, as is done in the Truck Series.  A big advantage to this is that NASCAR can change the spacers relatively quickly and easily.  It presents a possible inequality for the teams:  Because the engines are designed differently, they react to changes in airflow differently and one manufacturer might be disadvantaged more than others by a tapered spacer change made on short notice.  They’re looking at taking 90 hp out of the current 900+hp engines.
  • The aerodynamic package can be changed via additional parts (like roof rails, wickers or sharkfins, as we’ve seen in the past) and by changing the spoiler and splitter.  The disadvantage is that aerodynamics are especially subject to the law of unintended consequences.  The aerodynamics of the car play a huge rule in keeping the car on the ground, so any changes have to be vetted for safety in case of spins and collisions.  There’s also the issue that aerodynamics changes (like a wing vs. a spoiler) tend to be very visible and fans really like the look of the Gen-6 car.

Anyone hoping for a simple, fast solution is going to be disappointed.  A car is a complex system.  Changing one part often changes things you might not have expected to change.  NASCAR has to balance their experiments with ensuring the teams have enough time to get parts ready and do their own testing to optimize their cars within the new rules.



Dec 092013

Chase Elliott won, then lost the Snowball Derby last weekend. His car was disqualified for having tungsten ballast instead of the mandated lead ballast.  Ballast is weight added to the car in strategic locations to help the car handle better.

A number of news reports have noted that ‘tungsten is heavier than lead’, which is only true when you’re comparing two pieces of metal the exact same volume.  I learned this lesson when I was working on my book, The Physics of NASCAR.

It was 2007, I believe, when Kirk Almquist, then Elliott Sadler’s car chief, brought me two blocks of metal the same size.  He held them out for me to see, but didn’t let me hold them.  They were both a rather unimpressive dull grey.

“One of these”, he said, “is tungsten.  The other is lead.   Which is heavier?”

I made a quick mental recall of the periodic table (which was nowhere near as neat or organized as the one I’ve shown here from webelements.com, the best place on the web for periodic table information.)


Tungsten has the atomic symbol is W because the element was discovered as part of a mineral called Wolframite , which has a lot of tungsten in it.  Lead is Pb, which comes from the Latin plumbum, meaning “liquid silver”.  ’

Tungsten is atomic number 74 and lead is atomic number 82.    With a few exceptions, the larger the atomic number, the heavier the atom.  The atomic weights (how much equal numbers of atoms of each substance weigh) are  right there on the periodic table.  A lead atom is about 1-1/8 times heavier than a tungsten atom.  So I guessed lead.

Kirk got a big smile on his face and handed me the blocks.   The tungsten block was a lot heavier than the lead block.

Why is a tungsten block heavier than the same sized lead block if lead atoms are heavier than tungsten atoms?  It all has to do with how tightly the atoms are packed when they form a solid.  The numbers on the periodic table just refer to the atoms, but the atoms pack themselves into regularly ordered patterns when they form solids.  The more closely the atoms pack in, the higher the density of the solid.

The density of lead is 0.410 lb/in3, which means a cube of lead one inch on all sides weighs 0.41 pounds.  Tungsten has a density of 0.70 lbs/in3, which means that a cube of tungsten one inch on all sides would weigh 0.70 lbs – 1.74 times more than the same sized cube of lead.

In ballast, we’re usually not talking about a pound at a time:  we’re talking, say, 25 pounds.   Ballast is usually installed into a car’s frame rails, so a typical cross-section for ballast is 2-5/8″ x 3-5/8″.  Twenty-five pounds of tungsten would be 3.75″ long, while twenty-five pounds of lead would be 6.40″ long.

This is important because the weight distribution makes a huge difference in how a car handles.  The weight pushing each tire into the track creates grip.  The more weight pushing down on a tire, the more grip it has.  Using a denser weight, like tungsten, allows you to more precisely place the weight.  That allows you to do things like lower the center of gravity, or shift the weight from left to right and front to back in a way you can’t do with the physically larger piece of lead.

Elliott said that it was an oversight (and there’s no reason to believe it wasn’t), but rules and rules and they lost their win.

No Tungsten Allowed

Why is tungsten outlawed in many lower-level racing series?

Stock Car Steel and Aluminum Company (a typical supplier of race metal) will sell you a piece of tungsten 2-5/8″ x 3-5/8″ x 6″ long for $1876.88.  A comparable lead weight would cost you somewhere around $100.  Lower-level series don’t want to price the teams out of competition.  When one team gets an advantage, all the others are going to have to do the same thing to keep up.  It becomes a cost issue.

Tungsten is so expensive because it is more rare than lead and it is just harder to deal with.  Tungsten has a very high melting point (6192 F vs. 621 F for lead), which means that shaping it into bars requires some heavy duty furnances.

Tungsten is also more difficult to machine because it is hard and brittle unless it is made very very pure (which is also expensive).  Many machine tools are made from tungsten carbide (WC), one of the hardest carbides that exists.

There is even a trend now to make jewelry from tungsten and tungsten alloys, which raises a big problem:  if your gold wedding ring gets stuck on your finger, you can cut it off.  You can’t do that with tungsten.  (The solution is that you have to take advantage of the brittle nature of the material and crush it without crushing the fingers.)


Nov 222013

Now that the season is over, it’s time to look through the statistics from the year.  One big story this year was Danica Patrick’s rookie season in Sprint Cup.  She didn’t set the world on fire:  One top ten, one pole, five laps led and only thirteen lead lap finishes put her in 27th place for the season.

Tony Stewart, when asked about Danica’s rookie year, said that he saw ‘potential’.  Potential tends to be an ephemeral thing and numbers geeks like me strive to put a quantitative slant on everything, so I thought I’d look at the numbers and see if there was anything we could glean from comparing different driver’s rookie year stats.  With thanks again to the folks at racing-reference.info for the numbers, here goes.

I didn’t include stats like average starting position or poles because, frankly, you don’t get a championship that way.  I focused on how drivers finished.  The graph below shows the percentage wins, top five and top tens for a number of drivers, ranging from champions to drivers still proving themselves and, yes, two of our rookie-of-the-year competitors.


I think it is fair to conclude that the best drivers in the series – the multi-time champions like Johnson and Stewart – were just good from day one.  Finishing almost 60 percent of your races in the top 10 in your first year is pretty darned impressive.  The guys who looked like champions in their first year usually became champions (or came pretty close).

But the converse doesn’t hold.  A slow start doesn’t preclude the possibility of your becoming a champion.

If you look at the graph above to find a driver whose rookie year is comparable to Danica’s, you inevitably land on Brad Kezelowski.  His rookie stats weren’t that different than Danica’s.  She had one top-ten, he had two.  Neither had any top fives or wins.  They both had a pole.

So maybe there’s something that average statistics, like top tens and top fives don’t tell you.

Digging Deeper:  Histograms


A histogram plots the frequency of occurrence – for example, how many times a driver finished within each particular range of finishing positions.

I chose this kind of analysis because it’s the next step up from an average finishing position.  You can take two drivers with the same average, and one could finish 17th every race, while the other alternated between winning and crashing out in the first lap.    Someone once told me that ‘averages hide a multitude of sins’ .

I broke the finishing positions into five-position segments, but I broke out wins separately.  The histogram to the right shows Jimmie Johnson’s finishes for his rookie (2002) season.  The bar corresponding to ’35′ on the chart at right shows that Jimmie Johnson had four finishes between 35th and 39th that year.  The bar corresponding to ’5′ shows that Jimmie had 14 finishes between P5 and P9.   Johnson had an average finish of 13.5 and finished 5th in the standings that year.

Stewart1999The histogram for Tony Stewart’s rookie season (1999) looks a little different than Johnson’s in the details, but (like Jimmies) it’s skewed to the right-hand side of the plot (meaning more good finishes).   Stewart had an average finish of 10.3 and finished 4th in the standings.

And then we come to Kezelowski, who had an average finish of 22.4 and finished 25th in the standings.  Unlike Johnson and Stewart, who have significant bars for top fives and wins, there are no bars for Kezelowski.  He had a few bad finishes, but he consistently ran between 25th and 10th, with more of the finishes being on the higher end of that range.


Which brings us to Danica.  Even though she finished in 27th place (only two behind Brad in his rookie year), the statistical distribution of her finishes looks much different than Keselowski’s.


The mode of a group of numbers is the number that appears most often.  It’s the most probable outcome – and the highest bar in these histograms.  Brad has a pretty even spread between 30-10, but Danica has a pretty significant peak at the 25-29th place finishing positions.  She had a lot of finishes in the 25-29, while Brad was almost equally likely to finish 10th as 30th.

How Drivers Change

The big question, of course, isn’t how anyone did last year – it’s how they’re going to do in the future.  If there were some magical algorithm that allowed an owner to predict that, if they put three years of development into a driver, he or she would pay off, they’d have no problems deciding who to keep and who to let go.

I was curious about how drivers changed.  If you start off good, there isn’t much room for improvement, right?


This histogram compares Jimmie Johnson’s finishes in 2002 with those of this year.  He’s got fewer bad finishes and increased the number of wins, top 5s and top 10s.  Bad finishes are tricky because in a sport like this, you can get a bad finish through no fault of your own if you get caught up in someone else’s accident.  I haven’t looked at it in detail, but my first glance suggests many of the bad finishes for drivers who don’t have a lot of bad finishes are at the short tracks and the superspeedways, or they’re due to equipment malfunctioning, like a motor or transmission giving out.

What about Brad, whose rookie year wasn’t quite as promising?

KezTimeThis histogram compares Brad’s rookie year, 2010 with his championship year, 2012.  Look at the difference in finishes in just two years.  With the exception of a very few bad finishes (one was Daytona) every finish was 19th place and up.  What happened in those two years?  Some experience.  A new crew chief with whom Kezelowski seems to have really bonded.

What Does it All Mean?

If a driver starts off with a slew of top 10s in his first year, the chances are very high that driver will continue to run at the top as his or her career progresses.   You cannot, however, make the converse argument:  a driver with a weak rookie year may — or may not — become competitive.  We’ve seen some good drivers from other series come to NASCAR and struggle.

There are many factors that go into winning:  you have to have most of them to run well.  Sometimes something like changing crew chiefs, owners or even being in the final year of a contract will radically change how a driver runs.  Look at Joey Logano when he moved to Penske, or Matt Kenseth when he moved to Gibbs.

Now… that isn’t to say that there aren’t some clues that might tell you whether a driver is destined for greatness or mid-pack purgatory.  We’ll dive deeper into the data next time.



Nov 142013

Hard to believe it’s winter, but we got our first snow already. Here’s the news of the week.

  • It’s holiday shopping time – great idea for your gearhead: magazine subscriptions.
  • Despite hoping for a down-to-the-last-lap Homestead finale, all the stats geeks cite a pretty high probability Johnson takes it all.
    •  36 Races notes that Johnson has a 91% chance of winning the championship, but also that Harvick has a 3% chance of taking home the title.
    • Focusing more on who wins the Homestead race, PitRho has an interesting first choice for your fantasy team:  Parker Kligerman.
  • @nascarnomics looks NPR’s “esteemed commentator” Frank DeFord’s assertion that NASCAR fan numbers rose as speed increased and now that we’re only getting marginal increases in speed, that explains the declining attendance.  He analyzes attendance vs. pole speed and the results are very interesting.
  • F1′s all aflutter about the ugly noses on the 2014 car.
  • Have you ever seen a string theorist interviewed by a cat?  If not, you really should.

And in my news, I’m busy getting things ready for the end of the NASCAR season.  Whole lot of interesting stats I’ve found looking at the year as a whole.  Those’ll be coming up soon…


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