Senin, 14 Maret 2011

Fill ‘Er Up!

It’s just not that simple anymore.
Since the days way back in the 1950’s when Leonard Woods of Woods Brothers’ racing fame began tinkering with NASCAR’s pit stop processes and found a huge competitive advantage by shaving seconds off their driver’s pit stops, the science of making a quick, efficient pit stop has become a virtual art form.

As a result of Leonard Woods’ pioneering pit crew analysis and the changes made, today a group of people is selected for certain physical and mental attributes and molded into a team. They’re choreographed into performing specific functions (jacking a race car up and lowering it, changing tires, filling the fuel tank and making chassis adjustments) as quickly as possible. Their job is to constantly practice those functions working together, all while being tutored by their very own pit crew coach and under the watchful eyes of a demanding crew chief and an impatient driver.


From those early days when pit stops lasting a minute or more were commonplace, the pitting process has evolved to the point that a pit crew taking over 14 seconds to change four tires, completely fuel the vehicle and make minor chassis adjustments is chastised by the crew chief. Now think about that. If it takes more than 14 seconds to carry out those jobs, the pit crew stands to be admonished!

Enter 2011 and NASCAR’s mandated switchover to 15% ethanol racing fuel…

Suddenly a whole new set of potentially time consuming circumstances have presented challenges to be resolved. The crux of the problem being that ethanol attracts atmospheric moisture and is consequently easily contaminated. To avoid this, a whole new gas can had to be introduced that featured a “closed system”. The cans in use this season are easily recognizable due to a clear plastic tube running parallel to the metal fill spout. It acts to return air and any excess fuel back into the can while the car’s tank is being filled (The old cans allowed outside air into the tank filling process that aided in speeding the whole procedure along [and released fuel vapor into the atmosphere]). These new “closed system” cans actually take more time to empty into the car’s fuel tank. The new cans also must have what I call a quick shut-off valve feature or better yet, a sure shut-off valve at the end of the fill spout that must be precisely mated to and removed from a receiver fitting at the top end of the car’s fuel tank neck. The valve adds length to the fill spout tube. These new gas can additions have resulted in a can that has several moving parts and weighs at least 15 pounds more than the old can when full of fuel (from what was 85 lbs. when filled to possibly over 100 lbs.). And last but not least, the “closed system” fueling process was supposed to eliminate the excess fuel problem presented by the old filling system created when the gas can was lifted away from the car’s fuel receiver and a fairly large amount of excess fuel would slosh to the ground. To solve this problem with the old fueling process, a seventh “over the wall” person became necessary to stand beside the gas can man and catch any excess fuel in what became known as a “Catch Can” held directly below the car’s fuel receiver. Now NASCAR has eliminated that seventh “over the wall” man.

So, in a nutshell, here is the set of new, time consuming circumstances and an ongoing safety concern the pit crews have to contend with:
1. The closed system fuel can takes longer to empty.
2. The valve at the end of the new can’s fill spout must be precisely mated with the fuel tank’s neck receiver at a certain angle. If the two components are not properly mated, air will get into the process slowing an already slow filling procedure.
3. The valve must also be removed from the car’s receiver in a certain way or it will hang.
4. The new can has a longer fill spout and is 20% heavier.
5. The new can still results in fuel being spilled.
And 6. One less person is now allowed over the wall.

After three Sprint Cup races so far this season, here are a few different approaches some of the teams are now employing or will employ to address these problems:

1. The supposed cost savings to be enjoyed with one less person in the pit crew has been negated by the need for another man behind the wall to hand the gas can man his second fuel can when the need arises.

2. The height and angle at which the fuel can is held when approaching the car is critical to making a proper hook-up with the car’s receiver. This requires a tall gas can man (preferably around 6’2”).

3. To expedite the fueling process its been found the new man behind the wall who hands the second full can to the gas can man must also be tall.

4. The longer and heavier gas cans require even stronger gas can men who can shoulder and carry it, pivot to the car while holding it at the proper height and angle and then slam the can home.

5. The loss of the catch can man puts added responsibility on the backs of other “over the wall” crew members to make rear chassis adjustments, assist when need be with the fueling process and do it quickly while also handling their original duties.

6. The gas can man must pay close attention to the rear tire changer trying to anticipate when he will get his job completed so he can quickly remove the gas can from the car’s receiver before the driver tries to speed away.

For a look at a good 2011 pit stop, here's HMS’s number 48 team at work last month in Phoenix:

Now here’s a look at Roush-Fenway’s number 16 crew at work in Las Vegas…

What was wrong with that picture?

As it stands, in order to completely fill a car’s tank on green flag fueling stops using two cans of fuel, at least 14 seconds will be needed (6.5 seconds per can and one second to make a can switch). Something we may see this year as a result: A can will be jerked out of a gas can man’s hands when the driver just can’t wait any longer, unexpectedly pulling away from his pit.

When split seconds transmit into football field lengths at 190 mph, rest assured, racing engineers and pit crew coaches will be attempting to figure out how to get fuel out of these new cans and make pit stops as fast as possible well into the future.
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If you’ve got a few minutes, here’s a unique Sports Science look at Joe Gibbs Racing’s number 18 over the wall crew from last year that analyzes their work in a two part video. Check out the slow motion shots of the front tire changer, they’re really something.

Kyle Busch Pit Crew by Sports Science – Part One




Part Two

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