Pit stop
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- For a technique to cause a car to spin around (and stop) quickly, see PIT maneuver.
In motorsports, a pit stop is where a racing vehicle stops in the pits during a race for refuelling, new tires, repairs, mechanical adjustments, a driver change, or any combination of the above. The pits usually comprise of a pit lane which runs parallel to the start/finish straight and is connected at each end to the main track, and a row of garages (usually one per team) outside which the work is done. In American racing series, a pit lane consists of a number of pit stalls and a concrete pit wall which separates the pit lane from the infield, with the garages on a separate road in the infield; European racing series typically have the individual garage stalls open directly onto the pit lane through the team's assigned pit stall. Pit stop work is carried out by anywhere from five to twenty mechanics (also called a pit crew), depending on the series, while the driver waits in the vehicle (except where a driver change is involved).
By making pit stops cars can carry less fuel, and therefore be lighter and faster, and use softer tires that wear faster but provide more grip. Teams usually plan for each of their cars to pit one to three times and sometimes more. Choosing the optimum strategy of how many pit stops to make and when to make them is crucial in having a successful race. It is also important for teams to take competitors' strategies into account when planning pit stops, to avoid being "held up" behind other cars and unable to overtake them. An unscheduled stop, such as for a repair, can be very costly for a driver's chance of success.
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[edit] Pit stops in Formula One
In Formula One, cars make pit stops with the primary purpose of refuelling and changing tyres, although during the 2005 season tyre changing during the race was prohibited. Teams sometimes also make adjustments to the front and rear wings and perform minor repairs, most commonly replacing the nose and front wing assembly. A pit stop involves about twenty mechanics, with the aim of completing the stop as quickly as possible. It lasts for six to twelve seconds depending on how much fuel is put into the car. However, if there is a problem, such as a fuel pump failing or the engine stalling, or repairs having to be made, it can take much longer. Cars are fuelled at a rate of more than 12 litres per second. This is accomplished by a fairly complex closed system that pumps air out of the car's fuel tank as the fuel is being pumped in.
In a Formula One pit stop, the team's pit crew will set up fresh tires and all needed pit equipment when the car is approximately one lap away from making its stop. Because of the overhead fuel and pneumatic rig, the team may have all pit mechanics in position prior to the car's arrival, with the exception of the rear jack man.
The typical Formula One pit crew is as follows:
- The "Lollipop Man" holds the team's pit sign, helping the driver identify his pit stall on a possibly crowded pit road. During the stop, he holds the sign in position to remind the driver to keep his brakes on while tires are being changed, and then to remember to put the car in first gear once the jacks are lowered. He also gives the driver the sign to depart his pit stall by raising the sign from in front of the driver.
- The four tire changers, one at each corner of the car, have the sole responsibility of using a pneumatic wrench to remove the car's single locking lug nut from each tire, then reinstall it on the new tire.
- Eight tire carriers are used, two at each corner of the car, one assigned the task of removing the old tire from the car, and one to install the new tire on it. The front new tire carriers also have the responsibility of adjusting the car's front wing during the stop.
- The fuel man has the responsibility of attaching and removing the refuelling hose to the car's fuel recepticle, and must hold it in place during the entire fuelling operation.
- The front and rear jack men use simple lever-type jacks to lift the car and permit the changing of tires. The job of front jack man is considered the most hazardous, as it requires standing directly in front of the car as it enters its pit stall. By contrast, due to the location of his duties directly behind the car, the rear jack man is the only team member not in his working position before the car enters its pit stall.
- The fire extinguisher man does not actually work on the car; instead, he stands ready with a hand-held fire extinguisher to try and stop any accidental fires that may occur during a stop, at least long enough for the pit crew and driver to evacuate. This job became standard following Jos Verstappen's 1994 pit fire (see below).
- The starter man does not normally work on the car. His job is to stand ready with a starter tool to restart the car should the driver stall his engine during the stop.
Interestingly, unlike almost all other forms of racing that feature routine pit stops, Formula One rules limit teams to a single pit crew for the mandatory two cars entered. Therefore, teams must stagger their pit schedules so that only one of their two cars is in the pits at any given time. All other racing series that feature routine pit stops permit each car its own pit stall and crew.
[edit] Pit stops in NASCAR
Pit crew members were once the mechanics on the racecar, but most teams feature individuals dedicated to pit stops only. Although, most of the time, pit crew members work with the team in fabricating or designing the race cars during the week while training for their "pit job" on the weekends. The crew chief is the head person on a pit crew and assigns a Pit Crew Coach to help coordinate the pit stops and train the pit crew members how to stay in good physical shape. NASCAR regulations dictate that only seven individuals can go "over the wall" to service a racecar during a pit stop.
Thus, the active pit crew for a NASCAR pit stop is comprised of:
- The jackman: jacks up the car so that the tires can be replaced. The jackman will, also, usually pull the old right rear tire off of the car after the rear tire changer loosens the lug nuts. This is to help get the new right rear tire on faster. The jackman is the one who signals for the driver to leave the pits by dropping the jack.
- The front tire changer: changes only the front tires with air wrench. Removes lug nuts, removes the old tire, and tightens the new tire's lug nuts.
- The rear tire changer: changes only rear tires with air wrench. Removes lug nuts, removes the old tire, and tightens the new tire's lug nuts.
- The gas man: fills the car with gasoline with a special gas can. The gas man may, also, help pull old tires off of race car after lug nuts are loosened if the car does not need fuel or if the car needs little fuel and the gas man finishes his job before any one else.
- The catch can man: catches any fuel overflow in a small gas can and usually holds one gas can while the gas man fills car with the second gas can in the latter portions of a pit stop. The catch can man may also add or take out wedge and/or adjust the rear track bars during a pit stop. The refuelling gear is designed not to permit fuelling of the car without the catch can being attached to the car's overflow vent.
- Front tire carrier: brings the new front replacement tires over the pit wall and guides them onto the studs. He also rolls the old front tires to the pit wall after the front tire changer pulls them off of the car. The front tire carrier is usually responsible for clearing debris off of the grill of a racecar and/or pulling the front fenders away from the tire if necessary. He may also be responsible for adding tape to the grill during a pit stop for more front-end downforce.
- Rear tire carrier: responsible for bringing new rear tires over the pit wall. Typically, on the side of the car furthest from the pit wall, he will be responsible for guiding the new tire onto the studs, making any necessary adjustments to the rear track bar and/or wedge, and rolling the old tire back to the pit wall. On the side of the car closest to the pit wall, he is usually responsible for only sliding the new tire onto the studs.
NASCAR will occasionally make the decision, for safety reasons, to permit an eighth man over the wall, usually to clean the windshield, and in some situations, is permitted to attach extra dark shields to assist as the sun begins to set; in the event that this is permitted during a race, the eighth man may not make any changes to the car beyond these visibility issues. Races in Atlanta Motor Speedway, and in the past, Homestead Miami Speedway, North Carolina Speedway, and Phoenix International Raceway, were known where the setting sun would lead to glare issues on the cars.
[edit] Pit stops in Champ Car and IndyCar
In the Champ Car World Series and the Indy Racing League, a pit stop is a more complex operation than in NASCAR, but far less so than in Formula One. Rules permit six mechanics over the pit wall during a stop. The pit rules and procedures for both series are nearly identical due to their common origins in USAC National Championship racing.
During a routine pit stop in either series, the tires are layed out and three of the four tire changers are pre-positioned before the car enters its pit stall; the fourth tire changer, whose responsibility is the rear tire on the far side of pit road from the pit wall, doesn't take his position until after the car arrives, due to a rule against having the car run over the feed hose for the impact wrench used to change the tires.
Once the car arrives, the first step, taken while the fourth tire changer takes his position, is for a mechanic to insert the "vent hose" into its socket on the engine cowling. This hose vents the air out of the fuel tank, captures any overflow fuel, and also activates the car's built-in pneumatic jacks. Once the vent hose is in place, another mechanic attaches the refuelling hose to its socket, allowing the alcohol fuel to flow into the fuel tank. Simultaneously, the four tire changers remove the tires and install the new ones. Once the tire changes are complete, the front tire changers may use manual adjusters to adjust the angle of the car's front wing.
Once fuelling is complete, the fuel hose is removed from the car. After this, once tire changes are complete, the vent hose is removed, allowing the car to return to its wheels and rejoin the race. In the Indy Racing League, before the car departs its pit stall, a crew member must use a squirt of water to wash any excess fuel from the fuel hose and vent hose sockets; this is usually done with a pressurized hose by a crew member behind the pit wall.
Under normal conditions, a routine stop for either series lasts between ten and fourteen seconds.
[edit] Pit stops in endurance racing
In the various forms of sports car endurance racing, pit stops are a more leisurely affair, but no less important than in other forms of racing. While stops take longer, much more routine maintenance is scheduled during such pit stops, needed to keep the car running for as long as twenty-four hours; this includes major aerodynamic changes to deal with the changing temperature in such a long race, and replacement of certain wear-limited parts, such as brake pads.
Under the rules of the 24 Hours of Le Mans, also used by the American Le Mans Series, only five mechanics are permitted to work on the car. One man is permitted to fuel the car; all fuelling must be completed before any other service occurs. The other four mechanics on pit lane at any given time are typically two tire changers and two tire carriers, each of whom handles his task on only one side of the car. Automatic pneumatic jacks are used, integrated into the car itself.
In endurance racing, driver changes are mandatory; the shortest endurance races are scheduled for four hours, one hour longer than the longest nonstop time permitted behind the wheel. During a pit stop with a driver change, the new driver and a driver change assistant are permitted into the pit lane. The assistant, who may not do any mechanical work on the car, is tasked with helping the current driver out of the car, removing or swapping driver seat inserts, helping the new driver into the car, and helping the new driver tightly fasten his safety harness and connect his various helmet connections to the car's systems, including the two-way team radio and the drink bottle used to stave off dehydration.
A routine pit stop with no scheduled maintenance and no driver change generally lasts from thirty to forty seconds. With a driver change included, that time increases by about ten seconds. Should there be significant scheduled maintenance, such as changing brake pads, the stop can easily last well more than a minute.
Unlike most other forms of racing, the rules of endurance racing require that the car's engine be shut off during the stop.
[edit] Notable Pit Stops
- 1993 Australian Grand Prix: McLaren's Ayrton Senna came into the pit unexpectedly for new tires; the team serviced the car in under four seconds.
- 1994 German Grand Prix: Benetton driver, Jos Verstappen, came into the pits; while refuelling, some fuel is accidentally sprayed onto the hot bodywork of the car, a few seconds later the fuel ignited and Verstappen's car was engulfed in a ball of flames. Verstappen escaped the incident with burns round his eyes, as he had his visor up during the pit stop.
[edit] Trivia
- Pit stop has become popular slang for a washroom break.
- The Pit Stop is the name of each end point of a leg of The Amazing Race television game show series.
