Will the Gen-6 Car Affect the Number of Cautions?

 Cautions, Edwards Carl, math, Racing, Tony Stewart  4 Responses »
Jan 252013
 

I love the Gen-6 car.  Not as much as I love the Nationwide cars (but that’s got more to do with what I drive than it does the cars).  The big question is whether the decrease in cautions is going to be changed because of the new car.Let’s start (as we usually do) with the new car.

Graph4Let’s start (as we usually do here) with the data.  I’ve tabulated the data for cautions for the last twelve seasons and found that cautions have been decreasing since 2005, as shown,  for both the Nationwide and the Sprint Cup series.

In order to compare the two series and to compare between seasons within a single series, I’ve plotted the number of cautions per 100 miles.

In 2012, the Sprint Cup series had 1.57377 cautions per 100 miles.  They drove 13725 miles total, so that was 216 cautions total.

In 2012, the Nationwide series had 2.23969 cautions per 100 miles.  They drove 8240 miles, with comes out to 189 cautions — essentially the same number of cautions per mile they had last year.

Conclusion #1.  If the Nationwide drivers had driven the same number of miles as the Sprint Cup drivers, they would have had 307 cautions.

You’ll notice that I’ve drawn lines through each set of data.  They aren’t just a best fit by eye – I actually did a non-linear least-squares fit that determines the line that goes closest to all the points.  The data are decidedly linear and, more importantly, there aren’t any bumps or jump in, say, 2008, when the COT (which I guess is now the Gen-5 car) was introduced, or in 2011 when the Nationwide car was changed.  The data remained pretty consistent.

Conclusion #2.  Cautions are not affected much by the car that’s being driven.  Sure, I expect there to be some driver errors when a car doesn’t handle the way the driver expects it to behave; however, these guys catch on really quickly, so that’s going to be maybe 5 cautions.  Five out of 216 is like 2.3 percent, which is well within the error in the fit parameters.

Why are the cautions decreasing?  I’ve gone into this before, but I believe it is essentially because the drivers have a lot more experience now than they did in previous years.  There are a lot of veteran drivers in the Cup series right now, and I calculated that if you add up all the races run by the current crop of drivers, they have run a total of about 1000 more races in 2011 than they did in 2005.  That’s a whole lot of experience, and it’s distributed amongst the drivers.   Compare just two drivers:  Tony Stewart had run 248 races in  2005 and at the end of 2012, had run 500.  Carl Edwards had only run 49 races in 2005 – compare that to the 301 races he’d run as of today.  (I am only counting points paying races.  If you could somehow quantify the number of practice laps, time testing, etc., I think that would only make my argument stronger.)

So, in short, I don’t expect there will be any significant change in cautions because of the new car — up or down.  What do you think?

 

Is There Really a Second-Place Curse?

 Clint Bowyer, Dale Earnhardt Jr., Denny Hamlin, Edwards Carl, Jeff Gordon, Jimmie Johnson, Kasey Kahne, Keselowski Brad, Kyle Busch, Mark Martin, Martin Truex Jr, math, Tony Stewart  No Responses »
Dec 072012
 

One of the commentators after the final race in Homestead mentioned that Jimmie Johnson should be happy he finished in third because it allows him to avoid the “dreaded second-place curse”.
Anytime someone says something like that, it makes me wonder whether there really is a curse, or whether that person had just been talking to Carl Edwards.  So I analyzed a little data and guess what… there really IS a second place curse.

I used data from the last twelve years — from racing-reference.info, bless them!  After trying a couple of different approaches to making the data easy to visualize, I ended up with something a little more complicated than I would have liked.

Bear with me – it’s not as yucky as it looks.  I have plotted on the horizontal axis the place in which a driver finished in the first year listed, which we’ll call “X”.  I then calculated the change in positions of the same driver the next year (X+1) and plotted that on the vertical scale.  So the first set of data has X = 2000 and X+1=2001.

  • A positive number on the vertical axis means that the driver finished better by that many places in the following year. For example, +5 means that the driver finished five places better the next year than they finished the year before.
  • A negative number on the vertical axis means they finished worse the next year. A -5 means they moved down five spots in the final standings.

I went through and removed any special cases — like Mark Martin running full time one year, but not the next, Busch brothers missing races (that’s a different kinds of curse), people retiring, etc.  The graph below summarizes the top 16 finishing places and the change in final standing over the last twelve years.

There’s an obvious statistical implication:  If you finish second, for example, you have only one place to move up and forty one places to move down.  You’re either going to win the championship next year, become second again, or move down.  The probability is that you’re going to finish worse than second.

To look at the data in a slightly different way, I plotted it the same way they plot the daily activity of the the stock market:  the symbol shows you the average.  One line extends up to the maximum increase in position and one line extends down to the largest drop in position.

 

The first-place curse

In fact, if we’re going to call dropping in the standings a “curse”, then there is clearly a first-place curse that affects everyone except Jimmie Johnson.  Mose drivers who win the championship one year inevitably finish worse the next year.  When I say ‘drop in points’, it’s not a huge drop:  nine places was the most anyone who finished first dropped.

The average first time finisher fell almost five positions.  That’s including four consecutive ’0′s due to Jimmie Johnson.  If we exclude Jimmie just because what he did was really unprecedented (and unlikely to be duplicated), the average first-place finisher falls almost seven positions the next year – about the the same as the second-place driver.

The second-place curse

Second place shows a very similar story, only worse.  There is only one case in twelve years in which the second place finisher one year won the championship the next year.  That was Jimmie Johnson.  Whoops – Rick pointed out my mistake.  It was 2001 -2o02 and the driver was Tony Stewart!  On average (including Jimmie), the second place finisher finishes about seven positions lower the next year.

The three biggest drops in point standings (-15, -13, -11, -9 and -7) are due to Martin, Edwards, Biffle, Edwards and Hamlin.  There are no extenuating circumstances like crew chief changes, owner changes, etc. on which to blame the drops.  Four out of five of those drivers were all driving for Roush at the time… maybe there’s a Roush curse?

The bad news for Jimmie Johnson… and everyone else who made the chase

Here’s the bad news for Jimmie:  Yes, he avoided the second-place curse; however, no third-place driver has gone on to finish first or second the next year.  The best they’ve done was to match their third-place finish.

Yep, perhaps there’s a third-place curse as well, as third-place drivers finish an average of three places lower the following year.

In fact, you don’t find a finishing position in which there is an average probability of bettering your finish until 7th place.  On the graph above, you can see that the majority of finishes were improvements, although without one -11 change, it would be a much more positive number.  After that, it’s an oscillation between slightly better and slightly worse.

A caveat of this data analysis is that the Chase sort of messed things up going out past 10 because a driver in the Chase can’t finish lower than 10th, even if he misses races or otherwise would have fallen much lower without the Chase format.

 

Why was Michigan so hard on Motors?

 Chad Knaus, Engines, Hendrick Motorsports, Jeff Gordon, Jimmie Johnson, Michigan International Speedway, Tony Stewart  3 Responses »
Aug 232012
 

The Hendrick engine shop had four failures at Michigan.  The 24 and the 14 reportedly both had valve spring failures.  The worst was the 48, whose engine went south while leading with only six laps remaining.  Jimmie Johnson drove the car up to the hauler and walked back to his motorcoach with his helmet on, not talking to reporters.

I don’t blame him, especially when you realize how close he got before the motor let go.

High, Sustained RPM

Michigan is one of the tracks where the speed at which the motor rotates stays constant throughout an entire lap.  Watching the numbers from the television, most motors changed from only 7800 to 8500 rpm (revolutions per minute) throughout a lap.

Engine Diagram

Number of laps, or even miles are not the best way to gauge engine use because there is a huge difference between running at 8000 rpm and running at 3000 rpm.  What’s important is how many times a part is called upon to do it’s job.

The valves (one intake and one exhaust) are raised and lowered by the rotations of the camshaft (as shown above).  The camshaft is driven by the crankshaft.  When we say an engine is running at 9000 rpm, we mean that the crankshaft makes nine thousand rotations every minute – or 150 rotations every second.

Here’s the critical part:  The camshaft makes one rotation for every two rotations of the crankshaft in a four-stroke engine.  At 9000 rpm, the camshaft is running at 4500 rpm, which translates to 75 openings and closing of the intake (or exhaust) valve every second.  This means that the valve spring compresses and expands 75 times each second.

This is a linear phenomenon.  If the engine runs half as fast, each of these things happens half as many (37.5) times each second.  The faster the motor runs, the more movement, the more rubbing of parts and the more opportunity for pieces to break.

Watch the numbers this week at Bristol – you’ll see a much larger difference in speeds as the drivers slow down through the corners and accelerate through the straightaways.  Even more importantly, watch the changes in engine speed coming up next week at Atlanta, where you’re going to see similar high, sustained speeds.  The same issues will be in play for Charlotte and Texas.  This may just have been a case of a box of sub-optimal valve springs, or the engine shop may have been trying a more aggressive setup in preparation for similar track in the Chase.  I’m not worried – they’ll get it figured out (if they haven’t already).

By the Numbers

Let’s do a quick calculation.  The race time was 2 hours, 46 minutes and 44 seconds to run 201 laps.  There were 35 laps of caution, so (35/201=)17.4% of the race was run under caution and 82.6% of the race was run under green.

2 hours, 46 minutes and 44 seconds is 10,004 seconds.  82.6% of that is 8,263 seconds that were run under green.  If we take an average of 8000 rpm, which is 66.6 revolutions of the camshaft every second, the average valve and valve spring went through half a million up-and-down cycles.

Jimmie Johnson ran a top happy hour lap of 36.323 seconds.   Assuming an average of 8000 rpm, each lap at that speed adds another 2,421 cycles of the valve spring. Six laps means he was short 14,526 out of over a half-million cycles.  Think about sixteen valves and valve springs that make well over a million (including practices) successful executions and come up short by a few tens of thousands.

No wonder Johnson didn’t want to talk to the press.

 

Infographic: Current Drivers’ Rookie Years

 Darrell Waltrip, David Ragan, Edwards Carl, Jeff Gordon, Jimmie Johnson, Joey Logano, Kyle Busch, Martin Truex Jr, Tony Stewart  1 Response »
Jun 202012
 

Just out of curiosity, I pulled up some data from racing-reference.info on different drivers’ rookie years in the Cup series.  The data are from each driver’s first full year as a Cup driver.  I picked out some drivers who have gone on to become series champions, some that will likely go on to become champions, and some who are struggling.  I was wondering how predictive first year stats are of future performance.

The first graph shows how good drivers were at finishing races.  The blue bars are the percent of races in which the car was running at the end of the race, and the red bars are the percent of races in which the driver finished on the lead lap.

The second graph and third graph analyze finishing position.  The second graph summarizes wins (blue), top fives (red), top tens (green) and poles (purple).  All are expressed as a percentage because not all drivers ran 36 races in their first year.  The data are a lot more scattered here than they were in the first graph.  It’s striking that Stewart, Johnson and Edwards each finished in the top 10 in over (or almost over 50% of the races).


Finally, the third graph compares how each driver finished compared to other drivers.  The blue bar is where the driver finished in the drivers points at the end of the season.  (Lower is better, of course.)  The red bar is the average finishing rank over all races that season.  Again, Johnson, Stewart and Edwards stand out in contrast to the other drivers.

 

 

Richmond Redux: Relative Velocity

 Edwards Carl, NASCAR, Racing, Richmond, Tony Stewart  Comments Off
Apr 302012
 

NOTE: Some clarifications added 1:00 p.m. 4/30/12. Thanks to all the commenters, especially @nateryan!

I think Dave Moody did a good job breaking things down. The situation is confounded because there were so many different complications. Who from NASCAR is duly authorized to tell a spotter/crew chief/driver their position? Is it the team’s responsibility to make sure they are lined up the right place or NASCAR’s?  Should NASCAR have held off another lap to make sure that the teams knew what was going on?

The only thing this blog attempts to show is that one should never accept what one sees without questioning it because there are often explanations for why what we think we saw isn’t actually correct.  See my take on technology and data in motorsports.

Of all the things I am mandated to teach in intro physics, the problem where you are swimming across a river and there is a current and you have to figure out at what angle you swim so that you counteract the current and go directly across the water is my absolute least favorite.  I am hard pressed to find a case in which my students have cause to need to know how to do this.

Richmond may have given me a new way of teaching the importance of relative motion.  Although the magnitude of the speed does have an effect on interest, when you come down to it, the crux of racing is whether Car A is running faster than Car B.  It doesn’t matter if Car A is running 180 mph and Car B is running 179 mph, or if Car A is running 150 mph and Car B is running 149 mph.  You win because you are faster than the other car.

Although the restart controversy regarding the 14 and the 99 seems to be more a matter of a communications screw up (both cars claim they were told they were P1), it raises an interesting issue in terms of what we perceive vs. what actually is.  Even sat at a train crossing and had the momentary feeling that the train was standing still and you were moving sideways? Here’s a series of animations I put together really quickly. See if they do the job.

Take a look at the video below and decide which ball is accelerating and which ball is moving at constant speed.

Clearly, the blue ball is accelerating and the yellow ball is moving at constant speed. You can see this more clearly by marking the ball every ten frames, as I’ve done below. Exact same motion, but with markers:

The hallmark of acceleration is that the distance traveled over the same time interval increases. See how the blue balls are more and more spaced apart? That’s acceleration in a nutshell.
Now try this one: Which ball is accelerating this time?

The yellow one, right? Let’s try it again with the markers.

You can see from this that the yellow ball was actually moving at constant speed. The blue ball was decelerating. Because the 14 spun its wheels, it was not accelerating and that made the 99 look like it was accelerating even faster. If you had a frame-by-frame video of the actual restart, you could do the exact same type of analysis with the actual cars and settle for sure whether the 99 was accelerating prior to the starting box.

We judge things by how they look relative to other things. To be a good judge of relative motion, you have to reference your observations to something fixed – like the lines on the animation, or a track wall, or something that isn’t also moving.

This simple demonstration isn’t meant to call into question whether the penalty was right, or who screwed up – just to make people realize that what you see isn’t always what happened.

Phoenix: Relay Race?

 Electronic Fuel Injection, Engines, Fuel Mileage, Mark Martin, Rodney Childers, Tony Stewart  1 Response »
Mar 062012
 

The race at Phoenix was the first non-restrictor-plate race.  A number of drivers experienced engine-related problems, leading some media outlets to start blowing the “EFI problems” horns as loudly as possible.  Mark Martin, the pole sitter, was an unfortunate casualties of a “flipped circuit breaker”.  One of the most interesting exchanges to me was a series of tweets and a radio interview with Mark Martin’s Crew Chief Rodney Childers (@rchilders55) in which Childers repeatedly said it not “an EFI problem”, the radio commentators persisted in saying that it was.

Here’s his verbatim tweets (and if you’re not following him on twitter, please do!)

Man I hate that!! We had a breaker POP on our ECU for the fuel injection about half way. Which makes it switch to a safety fuel map.

It popped about half way.. it didn’t affect the performance. Just the Mpg, which made us have to pit. But we are really happy..

That made our mileage go from 4.2 to 3.8… And no way we could have made it. Good job to mark and all the Aarons guys though.

The EFI deal isn’t really the issue.. probably a wiring issue that we have to figure out. We had the same deal happen in practice.

Each car has a relay box, which acts sort of like Mission Control.  I’ve said before that the ECU (Engine Control Unit) is the brain of the EFI system.  The ECU collects information from a number of sensors located in different places on the car that measure things like humidity, pressure, temperature, and air-fuel ratio.  The ECU makes decisions on what to do next based on the information it gets from the sensors, and it acts on those plans by sending messages to the rest of the car through the relay box.

What happens if one of the sensors stops working (or a wire breaks and the sensor, even though it works, can’t send information)?  If the ECU believed the data it was being given, it would have a rather warped view of reality and could start telling the car to do all types of goofy things, including some that could actually damage the engine beyond repair.

The EFI system is smart – smart enough to know when it is getting suspicious data.  Instead of acting on that data, a relay is triggered and the ECU changes over to an alternate engine map (what Childers called a ‘safety fuel map’).  The alternate map isn’t optimized for performance – it’s purpose is to allow you to keep running, but your performance won’t be as good as you would have with the information from the sensor and the optimized engine maps.   As an analogy:  You eat more efficiently when your eyes are open.  If someone blindfolded you, you could still eat, but it wouldn’t be as efficient (or clean) as with your eyes open.  This relay system protects the engine from the actions of a confused ECU.  You might not run as well, but you also might not destroy a whole engine.
The relays work on the basis of a voltage threshold.  They’re like an electron bouncer.   A relay has a maximum current or voltage it will tolerate.  Bob Pockrass reports these relays have limits at 5V and 100 mA.   If an electrical signal comes through with a higher voltage (or current, depending on the type of relay), the relay switches everything to an alternative circuit.  Unlike the circuit breakers in a house (which are normally on/off, in contrast to these, which are circuit 1/circuit 2), it’s very difficult to re-set the relays.  It’s not like there’s a switch that the driver or a crew member can reach down and flip back.  When they flip, you’re pretty much stuck with them for the rest of the race.
Teams will be looking for anything that might cause the relay to flip.  That could be a wire that vibrated loose, or an electrical spike (like, say, the spike you get when you turn a switch on or off perhaps…?)  I understand some teams are switching to boxes without relays – but then you take a chance that something gets out of whack and you blow up your engine entirely.  One of the real pains in the neck with a short or a transient spike is that they can be hard to reproduce.  You can do the same thing 10 times and the problem may only happen one time out of those ten.  Makes for some long nights for the engine shops.
Childers tweeted that the mileage dropped from 4.2 mpg to 3.8 mpg – that’s just about a 10% drop in efficiency.  Phoenix is a one mile track, which means that the change in fuel mileage cost them nine laps per tank of fuel.  When teams are scrapping for one-percent increases, a 10% decrease is just going to kill you.
Keep in mind that we’re in uncharted territory.  NASCAR teams are subjecting these systems to environments they haven’t seen before.  I expected a few problems like this at Phoenix and I expect a few more in Las Vegas.  Teams will figure out how to make their system withstand the high-vibration/high-temperature world under the hood of a race car and drivers will gradually learn which of their techniques still work with the new system and which ones they’re going to have to change.
And if you’re wondering exactly what an engine map is, I’ve got a video going up on Friday to explain it.

 

Not Fine with Me!

 Electronic Fuel Injection, Greenness, Keselowski Brad, public relations, Tony Stewart  6 Responses »
Nov 192011
 

C’mon NASCAR – I keep trying to defend you and you keep making it hard for me.

@jeff_gluck reports that @nateryan told Brian France that NASCAR seems like

“…an autocratic regime that doles out punishment in a capricious manner.”

While I agree with those sentiments entirely, a slightly different word comes to my mind:  “chicken%$!#”

Seriously… what other sport has a secret rule book and issues secret fines?  (I’ve called this a “speach limit” elsewhere.)

Let’s look at another case of a driver making pretty strong comments to see how NASCAR might have handled the Keselowski incident.  Tony Stewart has made a number of very pointed criticisms of  Goodyear’s tires.  In some cases (Indy), the criticism was right on target.  After others (Atlanta 2008), it was perhaps not as much.  Stewart said:

“If I were Goodyear, I’d be very embarrassed about the tire they brought this weekend…If they can’t do better than that, pull out of the sport. I guarantee you that Hoosier or Firestone could do a better job than that…I guess that’s why they (Goodyear) got run out of Formula One, the IRL, CART and USAC, you name it.”

Goodyear’s response (in part):

“We believe that our engineering, research and tire development is second to none. We accept that drivers will have their own opinions about our tires. NASCAR president Mike Helton told us Monday that NASCAR is very grateful for the commitment Goodyear has made on behalf of building a good and safe product for our competitors, including this past weekend at Atlanta. NASCAR stands by our relationship and is proud to have Goodyear as a partner.”

“…we would like to correct an erroneous comment made by Tony Stewart. Goodyear decided to leave other racing series only because of the escalating costs of competition in those series. At least one other tire maker has done the same. For Goodyear, the enormous investment required to compete in those other forms of racing far outweighed the benefits derived from our participation. We see tremendous benefits in our 54-year relationship with NASCAR as the organization’s longest continuing supplier. We remain fully committed to, and are proud of, our relationship with NASCAR.”

Even NASCAR’s response was measured.  Mike Helton went on Stewart’s radio show and discussed the issue openly with Stewart. He said what many of us were already thinking:

“Tony, we’re all well aware of your opinion and your right to express your opinion, albeit, I think maybe a little bit too strong in this case.”

Goodyear invited Stewart to tour their tire-making factory and talk with the engineers who design the tires.  After that visit, Stewart moderated his comments and admitted that Goodyear is making their best effort with a difficult problem – while still noting that they don’t always (in his opinion) get it right.

After the tire debacle at Indy, who did Goodyear invite to help test the re-designed tires?  Tony Stewart.  It’s one thing if the people who are always happy with you say good things.  It really says something when your worst critic says you’re doing better.

I understand entirely NASCAR’s unwillingness to have the integrity of their officiating called into question.  That’s the analogy of telling the umpire he’s blind or cussing out the tennis line judge.  It’s poor sportsmanship.  The sanctioning body has the right to defend the integrity of the sport.  If they feel like a fine is the only way to do that, OK, but be upfront about it.

My problem with the Keselowski situation is that there is a fine line between “protecting the integrity of the sport” and forcing people to blindly toe the party line.  NASCAR suffers repeatedly from trying to be absolutely perfect instead of just acknowledging reality.  Reality isn’t bad.

Is corn-derived E15 a reasonable fuel choice to use on the track for this day and age?  Sure.

Is corn-derived E15 the fuel of the future and the solution to all our future energy woes?  Nope – and thankfully, NASCRA has started backing off the blind rhetoric – they’ve recently discussed  looking toward a future time when cellulosic ethanol (ethanol produced from fibrous, non-edible plant matter like corncobs, stalks, switchgrass, etc.) is ready to be used in racing.  It’s not ready right now, but the move to E15 is laying the groundwork for cellulosic E85.  Baby steps are perfectly acceptable — like the new EFI system.

Is a throttle-body EFI system at all comparable to the technology in the cars you and I drive?  Not at all. Is it a significant advance over the carburetor?  Yep. Is EFI going to save a lot of fuel?  No, not really.  Is it going to save the teams money?  Definitely not.  Does it move NASCAR closer to the cars their manufacturers are trying to sell?  It does.

Is it perfect?  No.

Is that OK?  Yes.

Brad Keselowski, the most recent secret finee, was tagged for his recent comments about electronic fuel injection.  (A story broken by Jenna Fryer of the Associated Press – a grad of WVU!.)

“I’m not a big fan of it at all. Carburetor technology is 50 years old but is very simple. The benefit of a carburetor is that it’s very, very easy to police. That’s why NASCAR stuck with that,” he had added. “They’ve been pressured into switching it through the green initiatives. In reality it’s no more efficient than what we have, and it costs a lot more.”

“We’re not doing this because it’s better for the teams.  I don’t think we’re really going to save any gas. It’s a media circus, trying to make you guys happy so you write good stories. It gives them something to promote. We’re always looking for something to promote, but the honest answer is it does nothing for the sport except cost the team owners money.

“Cars on the street are injected with real electronics, not a throttle body (like in NASCAR). So we’ve managed to go from 50-year-old technology to 35-year-old technology. I don’t see what the big deal is.”

So here’s how NASCAR might have responded (if I had been in charge of PR for the day):

“We appreciate Brad Keselowski’s apprehensive feelings about switching to electronic fuel injection.  Many people have negative initial reactions to any type of change.  We look forward to hearing his comments after he has a chance to actually use the system in a few races.  We expect 2012 to be an exciting, competitive season.

“But we must disagree with his assertions that the switch to EFI was motivated by trying to get good publicity, to save the teams money, or pressure from ‘green initiatives’.  NASCAR has a large number of constituencies we try to satisfy:  fans, manufacturers, sponsors, media partners, and drivers among them.  Like most businesses in this country, we’re doing our best to understand how we can contribute to making the country less dependent on foreign energy sources and more energy efficient in general.  The new EFI system is one more step in that direction.

“We realize that it is costing teams additional money in unusable inventory, purchasing new parts and training people – but that is part of the constantly changing nature of motorsports.  We are doing our best to phase in changes and work with the teams to minimize the financial impact as much as possible.

“As for the suggestion of pressure from the ‘green initiatives’, NASCAR has been recycling oil and automotive fluids at the track for a very long time.  Our newer programs (like track-based materials recycling) are being implemented because NASCAR believes in doing the right thing by our fans, our sponsors and our environment.

“While we respect all our participants’ rights to express their opinions, we hope they will do so in a responsible and constructive manner and work with us to make this a better sport for everyone.”

Physicists tend not to be the most subtle of people.  But I think the above does a pretty good job of suggesting that Keselowski’s comments were just plain uninformed without name calling or secret monetary fines that only make it hard for people like me to defend them.

You need only listen to SiriusXM NASCAR radio for a little while to know that there are always going to be people who are unwilling (or unable) to follow a logical argument and who will stick to their opinions even in the face of outright contradictory evidence.  Nothing NASCAR says or does – fines or statements – is going to change their minds.  But there are also a lot of people who will respond to a well-intentioned appeal to reason.

And now y’all know why I’ll never get a job in public relations!

 

 

 

 

 

How Mobil1 Goes in a ‘Quaker State’ Engine

 Engines, NASCAR, Oil, Tony Stewart  1 Response »
Oct 122010
 

ExxonMobil announced their sponsorship of Tony Stewart’s car for a partial 2011 season today.  Glad to see Mobil1 staying in the sport – especially since ExxonMobil are huge, huge supporters of math and science education.

Got a number of questions today about how a team that uses Hendrick engines – Hendrick having Quaker State as a sponsor – can have sponsorship from another oil company.  The questions were along the lines of “Will Stewart-Haas have to drain the oil pans when they get them from Hendrick?”

Here’s a quick answer, since I’m in the middle of a cross-country move and just about everything I own is in boxes:

NASCAR engines use a dry sump system.  That means that (unlike a passenger car engine) there is no oilpan on a NASCAR engine.  There are a couple of practical reasons for this.  One is that an oilpan is an invitation for disaster.  One bump on the bottom of a rough track and you’ve got a rupture.  Given that the NASCAR engine uses 22 qts of oil, that would be a lot of oil spilled on the track and a huge fire hazard.  You want to use as little energy as possible on friction, which means that the last thing you want is for your crankshaft to be spinning at 9,000 rpm through a pool of oil.  NASCAR engines use squirters to get the oil where it needs to go.  Removing the oil from an oil pan to a tank (located behind the driver) keeps the majority of the oil in a much safer location.  The oil tank is surrounded by a metal shield because the oil becomes extremely hot and the vaporization of the oil molecules creates quite a smell.  (The oil tank lid is what went missing a couple of years ago on the 99 car.)  The oil tank cover is on the leftmost of the photo.  The metal shield surrounding it is not shown on this picture that I took at the Hendrick Motorsports museum.

When a team gets an engine from another company, the engine is delivered dry.  Although oil is composed of mostly oil molecules (duh!),  a small fraction of the oil is non-oil additives.  These molecules have different tasks – helping to carry away heat faster and more efficiently, sweeping away small bits of debris, reducing friction, etc.   Each team chooses what kind (manufacturer, viscosity, etc.) of oil they want to use for qualifying and for the race.  Teams with ‘technical partnerships’ with oil manufacturers work with the engineers from that company and have access to the information that company has about friction-reducing additives, anti-fouling chemicals, etc.   The larger teams spend a significant amount of effort researching how different oil additives change the longevity, efficiency and temperature of the engine under different conditions (i.e. wide range of rpms, continuous high rpm).

There are non-technical issues as well.  Perhaps a team is willing to lease engines to a second team that isn’t performing very well.  Requiring them to use a particular brand of oil makes an implicit suggestion of endorsement by the oil company.  When my book (The Physics of NASCAR) was coming out, we joked about taking a picture of a driver or two behind the wheel with the book.   Then we realized that a couple of the drivers we were considering were running badly enough at the time that maybe it wouldn’t be the best publicity for the book.

Similarly, the oil company may not want to be seen to be endorsing that team.  So decoupling the oil and the engines makes a lot of sense for technical, as well as sponsorship, reasons.

If you want to learn more about oil, come out and see the science of motorsports exhibit at the very first USA Science and Engineering Festival, October 23-24 in downtown Washington DC.  Our booth will be about 13th and Pennsylvania.  We’ve got a new hands-on demo exploring the properties of oil, including viscosity and clearance.  Lots of cool things to play with, plus a couple hundred other exhibits, ranging from the nanoscopic to the entire universe.  It’s going to be great fun and I hope to see some of the blog readers there.