Restrictor plate
Encyclopedia
Intake
An intake , or especially for aircraft inlet, is an air intake for an engine. Because the modern internal combustion engine is in essence a powerful air pump, like the exhaust system on an engine, the intake must be carefully engineered and tuned to provide the greatest efficiency and power...
of an engine to limit its power. This kind of system is occasionally used in road vehicles (e.g., motorcycles) for insurance purposes, but mainly in automobile racing, to limit top speed and thus increase safety, to provide equal level of competition, and to lower costs; insurance purposes have also factored in for motorsports.
Racing series
A few top classes like Formula OneFormula One
Formula One, also known as Formula 1 or F1 and referred to officially as the FIA Formula One World Championship, is the highest class of single seater auto racing sanctioned by the Fédération Internationale de l'Automobile . The "formula" designation in the name refers to a set of rules with which...
limit only the displacement and air intake mouth dimension. However, in 2006 air restrictors (as well as rev limiters) were used by Scuderia Toro Rosso
Scuderia Toro Rosso
Scuderia Toro Rosso , also known simply as Toro Rosso or by its abbreviation STR, is an Italian Formula One racing team...
to facilitate the transition to a new engine formula.
Many other racing series use additional air restrictors.
- Formula 3, 2000cc, 215 hp
- Deutsche Tourenwagen MastersDeutsche Tourenwagen MastersThe Deutsche Tourenwagen Masters is a touring car racing series based in Germany, but also with rounds elsewhere in Europe....
, 4000cc, 470 hp - FIA GT ChampionshipFIA GT ChampionshipThe FIA GT Championship was a sports car racing series organized by the Stéphane Ratel Organisation at the behest of the Fédération Internationale de l'Automobile . The championship was mostly concentrated in Europe, but throughout the years has visited other continents including Asia and South...
(now FIA GT1 World ChampionshipFIA GT1 World ChampionshipThe FIA GT1 World Championship is a world championship sports car racing series developed by the SRO Group and regulated by the Fédération Internationale de l'Automobile . It features multiple grand tourer race cars based on production road cars and conforming with the GT1 regulations competing in...
) and other series using FIA GT regulations - Le Mans PrototypeLe Mans PrototypeA Le Mans Prototype is a type of sports prototype race car most notably used in the 24 Hours of Le Mans, American Le Mans Series and Le Mans Series...
s used in American Le Mans SeriesAmerican Le Mans SeriesThe American Le Mans Series presented by Tequila Patrón is a sports car racing series based in the United States and Canada. It consists of a series of endurance and sprint races, and was created in the spirit of the 24 Hours of Le Mans. Teams compete in one of five classes: LMP1, LMP2 and LMPC...
and Le Mans SeriesLe Mans SeriesThe Le Mans Series is a European sports car racing endurance series based around the 24 Hours of Le Mans race and run by the Automobile Club de l'Ouest . The series was originally named the Le Mans Endurance Series, but changed its name prior to the 2006 season...
have restrictors based on precalculated tables depending on the type and size of the engine and fuel- The ALMS in the 2010 season2010 American Le Mans Series seasonThe 2010 American Le Mans Series season was the twelfth season for the International Motor Sports Association's American Le Mans Series presented by Tequila Patrón. It was also the first season in which the ALMS used a revised structure for its four classes, as well as the first year in a three...
combines both LMP1 and LMP2 into a single LMP class on all races except 12 Hours of Sebring12 Hours of SebringThe 12 Hours of Sebring is an annual motorsport endurance race for sports cars held at Sebring International Raceway, a former Army Air Force base in Sebring, Florida...
and Petit Le MansPetit Le MansThe Petit Le Mans is a sports car endurance race held annually at Road Atlanta in Braselton, Georgia, USA. It uses the rules established for the 24 hours of Le Mans by the Automobile Club de l'Ouest , which are slightly modified if necessary, mainly to allow additional cars to compete.The race was...
; LMP1-categorized cars use a 5% smaller air restrictor compared to LMP2- categorized cars to balance performance in the races
- The ALMS in the 2010 season
Rallying
After Group BGroup B
Group B was a set of regulations introduced in 1982 for competition vehicles in sportscar racing and rallying regulated by the FIA. The Group B regulations fostered some of the quickest, most powerful and sophisticated rally cars ever built. However, a series of major accidents, some fatal, were...
cars were outlawed from rallying because they were too powerful (rumored to have reached 600 hp), too fast and too dangerous, the FISA
Fédération Internationale du Sport Automobile
The Fédération Internationale du Sport Automobile was the governing body for motor racing events. The organisation's origins date from 1922, when the Fédération Internationale de l'Automobile delegated the organisation of automobile racing to the CSI , an autonomous committee that would later...
decided that rally cars should not have more than 300 hp. For a while no special restrictions were needed for that (e.g. the Group A
Group A
In relation to motorsport governed by the FIA, Group A referred to a set of regulations providing production-derived vehicles for outright competition. In contrast to the short-lived Group B and Group C, the Group A referred to production-derived vehicles limited in terms of power, weight, allowed...
Lancia Delta HF 4WD had about 250 hp in 1987). But with development in the 1990s, Group A
Group A
In relation to motorsport governed by the FIA, Group A referred to a set of regulations providing production-derived vehicles for outright competition. In contrast to the short-lived Group B and Group C, the Group A referred to production-derived vehicles limited in terms of power, weight, allowed...
cars were rumored to have reached 405 hp or more. So the FIA
Fédération Internationale de l'Automobile
The Fédération Internationale de l'Automobile is a non-profit association established as the Association Internationale des Automobile Clubs Reconnus on 20 June 1904 to represent the interests of motoring organisations and motor car users...
mandated restrictors for supercharged and turbocharged engines in all categories (World Rally Car
World Rally Car
World Rally Car is a term used to describe racing automobiles built to the specification set by the FIA, the international motorsports governing body, and used to compete in the outright class of the World Rally Championship...
, Group A
Group A
In relation to motorsport governed by the FIA, Group A referred to a set of regulations providing production-derived vehicles for outright competition. In contrast to the short-lived Group B and Group C, the Group A referred to production-derived vehicles limited in terms of power, weight, allowed...
and Group N
Group N
In relation to motorsport governed by the FIA, Group N refers to a set of regulations providing 'standard' production vehicles for competition, often referred to as the "Showroom Class"....
).
This means that the rally version of a car like the Mitsubishi Lancer Evolution
Mitsubishi Lancer Evolution
The Mitsubishi Lancer Evolution, colloquially known as the Lancer Evo or Evo, is a high-performance sedan manufactured by Mitsubishi Motors. There have been ten official versions to date, and the designation of each model is most commonly a roman numeral...
can have less power than the street version (the "280" hp Evo VII was believed to have more than 300 hp, and in some markets the FQ-320, FQ-340, FQ-360, FQ-400 versions were sold, with the number representing the total horsepower).
It also means that the torque
Torque
Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....
and power
Power (physics)
In physics, power is the rate at which energy is transferred, used, or transformed. For example, the rate at which a light bulb transforms electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit...
curves of the engine are unusual. The engine produces peak torque and almost maximum power at a relatively low RPM, and from there to the rev limiter
Rev limiter
A rev limiter is a device fitted to an internal combustion engine to restrict its maximum rotational speed. This is usually carried out to prevent damage to the engine, however sometimes these devices are fitted to prevent an engine reaching the point at which it develops maximum power...
the torque drops and the power does not increase much.
In 1995 Team Toyota Europe
Team Toyota Europe
Toyota Motorsport GmbH is a Toyota division based in Köln, Germany. It was renamed from Toyota Team Europe to Toyota Motorsport GmbH in 1993...
used an illegal device to bypass the restrictor (allowing an estimated extra 50 hp).
Due to this the team lost their results in the 1995 season and was banned from rallying until the end of 1996.
NASCAR
NASCARNASCAR
The National Association for Stock Car Auto Racing is a family-owned and -operated business venture that sanctions and governs multiple auto racing sports events. It was founded by Bill France Sr. in 1947–48. As of 2009, the CEO for the company is Brian France, grandson of the late Bill France Sr...
's Sprint Cup and Nationwide Series currently uses restrictor plates at Daytona International Speedway
Daytona International Speedway
Daytona International Speedway is a race track in Daytona Beach, Florida, United States. Since opening in 1959, it has been the home of the Daytona 500, one of the most prestigious races in NASCAR. In addition to NASCAR, the track also hosts races of ARCA, AMA Superbike, Grand-Am and Motocross...
and Talladega Superspeedway
Talladega Superspeedway
Talladega Superspeedway is a motorsports complex located north of Talladega, Alabama, United States. It is located on the former Anniston Air Force Base just outside the small city of Lincoln. It was constructed by International Speedway Corporation, a business controlled by the France Family, in...
. NASCAR routinely states that the Sprint Cup restrictor plate reduces engine power from approximately 750 hp to approximately 430 hp.
The device limits the power output of the motor, hence slowing both the acceleration and the overall top speed obtainable on the tracks where the cars are so equipped. A major effect, however, is that all drivers tend to form very large "packs" of cars that run closely (there may only be one second separating the entire field at times) together for the majority of the race. These large packs reduce air resistance which allows the cars to run faster and makes drafting
Drafting (racing)
Drafting or slipstreaming is a technique where two vehicles or other moving objects are caused to align in a close group reducing the overall effect of drag due to exploiting the lead object's slipstream...
easier.
The restrictions are in the interest of driver and fan safety because higher speeds are closer to out-of-control than the 190 MPH range used for Daytona and Talladega; the severity of crashes at higher speeds is also much greater, shown by telemetry readings of wrecks such as Jerry Nadeau
Jerry Nadeau
Jerry Nadeau is a retired race car driver from Danbury, Connecticut. Nadeau competed in the 1994 Barber Dodge Pro Series and the 1996 Formula Opel Euroseries.-NASCAR career:Nadeau's NASCAR career began in 1995 in the Busch Series...
at Richmond and Michael McDowell at Texas that were far higher than registered on restrictor plate tracks. Drivers such as Rusty Wallace
Rusty Wallace
Russell William Wallace, Jr. is a past NASCAR Winston Cup Champion, currently a broadcaster on ESPN, car owner in the Nationwide Series, and a co-host of NASCAR Angels.-Early racing career:...
have also cited data showing that the sport's roof flap
Roof flap
A roof flap is an aerodynamic feature on race cars, mainly stock cars, which functions as an emergency spoiler to prevent the vehicle from lifting off the ground...
s cannot keep cars on the ground above 194 MPH.
At Daytona and Talladega, most races are marred by at least one multi-car crash as cars rarely become separated. Talladega has been considered the more likely track for these instances to occur as the track is wide enough to have three to four distinct lines of racing. With the new pavement at Daytona, three-wide racing is now possible and multi-car wrecks could become more common. The 2011 Daytona 500
Daytona 500
The Daytona 500 is a -long NASCAR Sprint Cup Series race held annually at the Daytona International Speedway in Daytona Beach, Florida. It is one of four restrictor plate races on the Cup schedule....
saw a record number of cautions including an early 17-car pile-up. These wrecks tend to be singled out for criticism despite multicar crashes at other tracks and the generally greater severity of impact on non-restricted tracks. In addition, the packs were far smaller in 1988 through 1990 until more teams mastered the nuances of this kind of racing and improved their cars (and drivers) accordingly.
The 2011 Sprint Cup season will be the last complete Cup season with carbureted engines. NASCAR has announced that it will change to fuel injection no later than the second race of the 2012 season (i.e., after the Daytona 500). It has not yet announced whether fuel injection will be adopted for the Daytona 500. This will result in the end of the current restrictor plates, but it is still possible that plates designed with fuel injection in mind may be used instead.
Reason for restrictor plates
There have been three reasons that NASCARNASCAR
The National Association for Stock Car Auto Racing is a family-owned and -operated business venture that sanctions and governs multiple auto racing sports events. It was founded by Bill France Sr. in 1947–48. As of 2009, the CEO for the company is Brian France, grandson of the late Bill France Sr...
used restrictor plates.
The first use came in 1970 in response to escalating speeds. Following testing and input from drivers such as David Pearson, Bobby Isaac
Bobby Isaac
Bobby Isaac is a former NASCAR Grand National champion.-Early life:Isaac grew up on a farm near Catawba, North Carolina, the second youngest of nine children...
, and Bobby Allison
Bobby Allison
Robert Arthur Allison is a former NASCAR Winston Cup driver and was named one of NASCAR's 50 greatest drivers. His two sons, Clifford Allison and Davey Allison followed him into racing, and both died within a year of each other....
, NASCAR mandated the use of a restrictor plate. Smaller engines, in the 358 cubic inch range, were exempt from the plates. The transition period lasted until 1974. As the early 1970s use of restrictor plates was considered a transitional process, and as not every car used restrictor plates, this is not what most fans call "restrictor plate racing."
The second use came following the crash of Bobby Allison
Bobby Allison
Robert Arthur Allison is a former NASCAR Winston Cup driver and was named one of NASCAR's 50 greatest drivers. His two sons, Clifford Allison and Davey Allison followed him into racing, and both died within a year of each other....
at the 1987 Winston 500
Aaron's 499
The Aaron's 499 is a NASCAR Sprint Cup Series stock car auto race held at Talladega Superspeedway in Talladega, Alabama. The race has always been held in late April or early May. The Aaron's 499 is also one of four races currently run with restrictor plates, the others being the AMP Energy 500,...
at Talladega Superspeedway
Talladega Superspeedway
Talladega Superspeedway is a motorsports complex located north of Talladega, Alabama, United States. It is located on the former Anniston Air Force Base just outside the small city of Lincoln. It was constructed by International Speedway Corporation, a business controlled by the France Family, in...
. Allison's Buick LeSabre
Buick LeSabre
1959LeSabre and all other 1959 Buicks not only got new names, but all-new styling as well, adopting the new GM B- and C-body used on all of the corporation's full-sized cars...
blew a tire going into the tri-oval at 200 mi/h, spun around and became airborne, flying tail-first into the catch fencing. While the car did not enter the grandstands, flying debris did injure several spectators. After a summer where the two subsequent superspeedway races were run with smaller carburetors (390 cubic feet per minute instead of 750 cubic feet per minute) proved to be inadequate to sufficiently slow the cars, NASCAR imposed restrictor plates again, this time at the two fastest circuits, both superspeedways: Daytona
Daytona International Speedway
Daytona International Speedway is a race track in Daytona Beach, Florida, United States. Since opening in 1959, it has been the home of the Daytona 500, one of the most prestigious races in NASCAR. In addition to NASCAR, the track also hosts races of ARCA, AMA Superbike, Grand-Am and Motocross...
for all NASCAR-sanctioned races and Talladega
Talladega Superspeedway
Talladega Superspeedway is a motorsports complex located north of Talladega, Alabama, United States. It is located on the former Anniston Air Force Base just outside the small city of Lincoln. It was constructed by International Speedway Corporation, a business controlled by the France Family, in...
for Cup races. The Automobile Racing Club of America
Automobile Racing Club of America
Automobile Racing Club of America is an auto racing sanctioning body in the United States, founded in 1953 by John Marcum. The current president of ARCA is Ron Drager. The ARCA RE/MAX Series races stock cars similar to those seen in past years in the NASCAR Sprint Cup Series, and indeed most cars...
also enforced restrictor plates at their events at the two tracks. In 1992, when the Busch Grand National series began racing at Talladega, the plates were implemented, in keeping with their use at Daytona .
In some tracks, NASCAR's concerns with speeds because of power-to-weight ratios result in restrictor plates at other tracks. The Goody's Dash Series (known now as the ISCARS series with its new ownership) used restrictor plates at Bristol
Bristol Motor Speedway
Bristol Motor Speedway, formerly known as Bristol International Raceway and Bristol Raceway is a NASCAR short track venue located in Bristol, Tennessee. Constructed in 1960, it held its first NASCAR race on July 30, 1961...
during at least the last years of the series' existence when the cars were using six-cylinder engines (compared to the traditional four cylinder engines), in addition to their Daytona races.
However, restrictor plates are not used for Camping World Truck Series trucks. Rather, air intake, aerodynamic, and, eventually, a tapered carburetor spacer were implemented for those races. Combined with the aerodynamic disadvantage of the trucks, this allows NASCAR to avoid the use of such equipment for the trucks, though the plates remain a standby method.
In 2008, the Nationwide Series and Truck Series began implementation of tapered spacers in the engines to restrict power compared to Sprint Cup cars at all 35 (NNS) and 25 (NCTS) races. The Nationwide Series still uses a restrictor plate and tapered spacer at the two tracks. The Trucks do not use any additional restriction except for the air intake restriction at the two tracks.
The third use came in 2000. Following fatal crashes of Adam Petty
Adam Petty
Adam Kyler Petty was a professional racing driver. He was the first fourth-generation driver in NASCAR history.-Early life:...
and Kenny Irwin, Jr.
Kenny Irwin, Jr.
Kenneth Dale Irwin, Jr. was a NASCAR stock car driver. He had driven in all three major of forms of NASCAR and had two total victories. Before that, he raced in the United States Auto Club against Tony Stewart, who was one of his fiercest rivals...
at the New Hampshire International Speedway
New Hampshire International Speedway
New Hampshire Motor Speedway is a oval speedway located in Loudon, New Hampshire which has hosted NASCAR racing annually since the early 1990s, as well as an IndyCar weekend and the oldest motorcycle race in North America, the Loudon Classic...
during the May Busch Series
Busch Series
The NASCAR Nationwide Series is a stock car racing series owned and operated by the National Association of Stock Car Auto Racing. It is promoted as NASCAR's "minor league" circuit, and is a proving ground for drivers who wish to step up to the organization's "big leagues"; the Sprint Cup circuit...
and July Winston Cup Series races, NASCAR adopted Modified
Whelen Modified Tour
The NASCAR Whelen Modified Tour is a stock car racing series owned and operated by NASCAR in the Modified division. The Modified division is NASCAR's oldest division, and its one of two open-wheeled divisions...
rules featuring a one-inch (2.54 cm) restrictor plate to slow the cars headed towards the tight turns as part of a series of reforms to alleviate stuck throttle problems which were alleged to have caused both fatal crashes. For the Winston Cup race, it was used just once at the 2000 Dura-Lube/Kmart 300
Sylvania 300
The Sylvania 300 is a NASCAR Sprint Cup Series stock car race held at the New Hampshire Motor Speedway in Loudon, New Hampshire.The Sylvania 300 has traditionally held in mid-September, however, the race has been rescheduled once in its history...
. Jeff Burton
Jeff Burton
Jeffrey Brian "Jeff" Burton , also referred to as JB or The Mayor, is a NASCAR Sprint Cup Series driver who drives the #31 Caterpillar Chevrolet Impala for Richard Childress Racing. Burton is the younger brother of Ward Burton, who is a former Sprint Cup driver...
led all 300 laps in the ensuing race, despite a 23-car two-abreast battle in the first ten laps, a dramatic charge past 22 cars in 100 laps by John Andretti
John Andretti
John Andretti is an American race car driver. He has won in CART, IMSA GTP, Rolex Sports Car Series and NASCAR. He was the last NASCAR driver to win a Cup race for the famous Petty Enterprises team.-Andretti family:...
(who finished seventh), and two charges by Bobby Labonte
Bobby Labonte
Robert Alan "Bobby" Labonte is an American race car driver in the NASCAR Sprint Cup Series. He currently drives the #47 Kroger/Clorox/Kimberly-Clark/Kingsford/Reese Towpower Hitches Toyota Camry for JTG Daugherty Racing. He currently resides in Trinity, North Carolina. He is married to his wife...
in the final 50 laps where he took the lead but Burton beat him back to the stripe. The use of restrictor plates, intended as an emergency measure pending a more permanent replacement in any event, was discontinued at New Hampshire for the following race for Cup only. However, the Modifieds still use a restrictor plate because the speeds are too great for that class of racecar without them. The track has since been changed with soft walls to improve racing safety. Restrictor plates remain a permanent fixture to the Modifieds and the racing has often broken 20 official lead changes for 100–125 laps of competition.
Rusty Wallace
Rusty Wallace
Russell William Wallace, Jr. is a past NASCAR Winston Cup Champion, currently a broadcaster on ESPN, car owner in the Nationwide Series, and a co-host of NASCAR Angels.-Early racing career:...
tested a car at Talladega Superspeedway
Talladega Superspeedway
Talladega Superspeedway is a motorsports complex located north of Talladega, Alabama, United States. It is located on the former Anniston Air Force Base just outside the small city of Lincoln. It was constructed by International Speedway Corporation, a business controlled by the France Family, in...
without a restrictor plate in 2004, reaching a top speed of 228 mi/h in the backstretch and a one-lap average of 221 mi/h. While admitting excitement at the achievement, Wallace also conceded, "There's no way we could be out there racing at those speeds... it would be insane to think we could have a pack of cars out there doing that."
The competitive quality of restrictor plate racing
A frequent criticism of restrictor plates is the enormousness of packs in the racing, with "Big One" wrecks as noted above singled out for condemnation despite the greater violence of "smaller" crashes on unrestricted tracks. In restrictor plate racing the packs have brought about an often-enormous increase in positional passing; at Talladega SuperspeedwayTalladega Superspeedway
Talladega Superspeedway is a motorsports complex located north of Talladega, Alabama, United States. It is located on the former Anniston Air Force Base just outside the small city of Lincoln. It was constructed by International Speedway Corporation, a business controlled by the France Family, in...
the Sprint Cup cars have broken 40 official lead changes sixteen times from 1988 onward, including both 2010 Sprint Cup races at Talladega, which had 87 official lead changes in the regulation 188 laps. (The 2010 Aaron's 499
2010 Aaron's 499
The 2010 Aaron's 499 was the 9th race of the 2010 NASCAR Sprint Cup Series season at Talladega Superspeedway in Talladega, Alabama. It started at 1 p.m. EDT on April 25, 2010. The 2010 Aaron's 499 was televised on Fox and was also broadcast on MRN radio at 12 p.m...
had 88 lead changes, but the 88th was on the 200th lap of a race extended by the Safety Car rule). Daytona International Speedway
Daytona International Speedway
Daytona International Speedway is a race track in Daytona Beach, Florida, United States. Since opening in 1959, it has been the home of the Daytona 500, one of the most prestigious races in NASCAR. In addition to NASCAR, the track also hosts races of ARCA, AMA Superbike, Grand-Am and Motocross...
has generally been less competitive because the age of the asphalt (the track was repaved in 1978 and again in 2010) has reduced grip for the cars and thus handling has impeded passing ability to a significant extent. The 2000 New Hampshire race was condemned because Jeff Burton led wire to wire; the plates were singled out as impeding ability to pass, a criticism contradicted by the use of restrictor plates in a Busch North support race the day before where the lead changed seven times in 100 laps and by the highly competitive nature of restrictor plated Modified races; as noted above the 300 also saw a 23-car battle for third in the first ten laps and a burst by 22 cars from John Andretti.
The criticism stems from reduction in throttle response brought by the restriction. The reduction in throttle response, however, has never been shown to have impeded ability to pass; the criticism was shot down in the first "modern" plate race, the 1988 Daytona 500
1988 Daytona 500
The 1988 Daytona 500 was held February 14 at Daytona International Speedway. Ken Schrader won the pole. The race is best remembered for Richard Petty's spectacular rollover crash in the tri-oval on lap 106, initiated when he was tagged from behind by Phil Barkdoll. Petty rolled over about eight...
, as the lead changed 25 times officially and saw several bursts where the lead changed several times a lap and also several bursts of sustained side-by-side racing, notably in the final 50 laps between Bobby Allison
Bobby Allison
Robert Arthur Allison is a former NASCAR Winston Cup driver and was named one of NASCAR's 50 greatest drivers. His two sons, Clifford Allison and Davey Allison followed him into racing, and both died within a year of each other....
, Darrell Waltrip
Darrell Waltrip
Darrell Lee Waltrip is a 3-time NASCAR Cup Series champion , 3-time runner-up , winner of the 1989 Daytona 500 and 5-time winner of the prestigeous Coca-Cola 600 ,...
, Neil Bonnett
Neil Bonnett
Lawrence Neil Bonnett was a NASCAR driver who compiled 18 victories and 20 poles over his 18-year career. The Alabama native currently ranks 35th in all-time NASCAR Cup victories. He appeared in the 1983 film Stroker Ace and the 1990 film Days of Thunder...
, and Buddy Baker
Buddy Baker
Elzie Wylie Baker, Jr. , nicknamed "Leadfoot" or more famously Buddy, is a former American NASCAR racecar driver.-Early life:...
.
Said Waltrip before the race, "I feel, as a driver, now I can do more than I could before (the plates). Now, instead of a car just blasting by me with a burst of speed and a lot of horsepower, he's got to think his way, he got to DRIVE his way around me."
In the 1971-4 period of restrictor plate racing Daytona and Talladega broke 40 official lead changes six times, while Michigan International Speedway
Michigan International Speedway
Michigan International Speedway is a two-mile moderate-banked D-shaped superspeedway located off U.S. Highway 12 on more than in Brooklyn, in the scenic Irish Hills area of southeastern Michigan. The track is used primarily for NASCAR events. It is sometimes known as a "sister track" to Texas...
, also restricted, broke 35 official lead changes in both of its 1971 races.