A restrictor plate or air restrictor is a device installed at the
intake
An intake (also inlet) is an opening, structure or system through which a fluid is admitted to a space or machine as a consequence of a pressure differential between the outside and the inside. The pressure difference may be generated on the ins ...
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
Auto racing (also known as car racing, motor racing, or automobile racing) is a motorsport involving the racing of automobiles for competition.
Auto racing has existed since the invention of the automobile. Races of various sorts were organi ...
, to limit top speed 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 One
Formula One (also known as Formula 1 or F1) is the highest class of international racing for open-wheel single-seater formula racing cars sanctioned by the Fédération Internationale de l'Automobile (FIA). The World Drivers' Championship, ...
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 (; literal translation of "Red Bull Racing Team"), commonly known as Toro Rosso or by its abbreviation STR, was an Italian Formula One racing team. It was one of two Formula One teams owned by Austrian beverage company Re ...
to facilitate the transition to a new engine formula.
Many other racing series use additional air restrictors.
*
Formula 3
Formula Three, also called Formula 3, abbreviated as F3, is a third-tier class of open-wheel formula racing. The various championships held in Europe, Australia, South America and Asia form an important step for many prospective Formula One driv ...
, 2000cc, 215 hp
*
Formula SAE
Formula SAE is a student design competition organized by SAE International (previously known as the Society of Automotive Engineers, SAE). The competition was started in 1980 by the SAE student branch at the University of Texas at Austin after ...
, 710cc, 20 mm restrictor.
*
Deutsche Tourenwagen Masters
The Deutsche Tourenwagen Masters (DTM, German Touring Car Masters) is a grand touring car series sanctioned by ITR e.V. who have been affiliated to the DMSB-FIA since 1984. The series is based in Germany, with rounds elsewhere in Europe. The ser ...
, 4000cc, 470 hp
*
FIA GT Championship
The FIA GT Championship was a sports car racing series organized by the Stéphane Ratel Organisation (SRO) at the behest of the Fédération Internationale de l'Automobile (FIA). The championship was mostly concentrated in Europe, but throughout ...
(now
FIA GT1 World Championship
The FIA GT1 World Championship was a world championship sports car racing series, developed by the SRO Group and regulated by the Fédération Internationale de l'Automobile (FIA), that was held from 2010 to 2012. It featured multiple grand to ...
) and other series using
FIA GT regulations
*
Le Mans Prototype
A Le Mans Prototype (LMP) is the type of sports prototype race car used in the 24 Hours of Le Mans, FIA World Endurance Championship, IMSA SportsCar Championship, European Le Mans Series and Asian Le Mans Series. Le Mans Prototypes were crea ...
s used in
American Le Mans Series
The American Le Mans Series (ALMS) was a sports car racing series based in the United States and Canada. It consisted of a series of endurance and sprint races, and was created in the spirit of the 24 Hours of Le Mans.
The American Le Mans' hea ...
and
Le Mans Series
The European Le Mans Series (abbreviated as ELMS) is a European sports car racing endurance series inspired by the 24 Hours of Le Mans race and organized by the Automobile Club de l'Ouest (ACO). The European Le Mans Series is similar to the fo ...
have restrictors based on precalculated tables depending on the type and size of the engine and fuel
** The ALMS in the
2010 season combines both LMP1 and LMP2 into a single LMP class on all races except
12 Hours of Sebring and
Petit Le Mans
The Petit Le Mans (French for ''little 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 (ACO), which ...
; LMP1-categorized cars use a 5% smaller air restrictor compared to LMP2- categorized cars to balance performance in the races
Rallying
After
Group B
Group B was a set of regulations for grand touring (GT) vehicles used in sports car racing and rallying introduced in 1982 by the Fédération Internationale de l'Automobile (FIA). Although permitted to enter a GT class of the World Sportscar ...
cars were outlawed from rallying because they were too powerful (rumored to have reached 600 hp), too fast and too dangerous, the
FISA
The Foreign Intelligence Surveillance Act of 1978 ("FISA" , ) is a United States federal law that establishes procedures for the physical and electronic surveillance and the collection of "foreign intelligence information" between "foreign pow ...
decided that rally cars should not have more than . For a while no special restrictions were needed for that (e.g. the
Group A
Group A is a set of motorsport regulations administered by the FIA covering production derived vehicles intended for competition, usually in touring car racing and rallying. In contrast to the short-lived Group B and Group C, Group A vehicles w ...
Lancia Delta HF 4WD
The Lancia Delta is a small family car produced by Italian automobile manufacturer Lancia in three generations. The first generation (1979-1994) debuted at the 1979 Frankfurt Motor Show, the second generation (1993-1999) debuted at the 1993 Gene ...
had about 250 hp in 1987). But with development in the 1990s,
Group A
Group A is a set of motorsport regulations administered by the FIA covering production derived vehicles intended for competition, usually in touring car racing and rallying. In contrast to the short-lived Group B and Group C, Group A vehicles w ...
cars were rumored to have reached 405 hp or more. So the
FIA
FIA is the Fédération Internationale de l'Automobile (English: International Automobile Federation), the world's governing body for all forms of motor sport where four or more wheels are used.
Fia or FIA may also refer to: People
* Fia Backst ...
mandated restrictors for
supercharged
In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement.
The current categorisation is that a supercharger is a form of forced induct ...
and
turbocharged engines in all categories (
World Rally Car
A World Rally Car is a racing automobile built to the specific regulations set by the Fédération Internationale de l'Automobile (FIA) and designed for competition in the World Rally Championship (WRC). The cars were introduced in 1997 as a repl ...
,
Group A
Group A is a set of motorsport regulations administered by the FIA covering production derived vehicles intended for competition, usually in touring car racing and rallying. In contrast to the short-lived Group B and Group C, Group A vehicles w ...
and
Group N
In relation to international motorsport governed by the FIA, Group N refers to regulations providing 'standard' large scale series production vehicles for competition. They are limited in terms of modifications permitted to the standard specific ...
).
This means that the rally version of a car like the
Mitsubishi Lancer Evolution
The Mitsubishi Lancer Evolution, popularly referred to as the 'Evo', is a sports sedan and rally car based on the Lancer that was manufactured by Japanese manufacturer Mitsubishi Motors from 1992 until 2016. There have been ten official versio ...
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
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
and
power
Power most often refers to:
* Power (physics), meaning "rate of doing work"
** Engine power, the power put out by an engine
** Electric power
* Power (social and political), the ability to influence people or events
** Abusive power
Power may a ...
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 the torque drops and the power does not increase much.
In 1995
Toyota Team Europe
Toyota Gazoo Racing Europe GmbH (TGR-E), formerly Andersson Motorsport GmbH and Toyota Motorsport GmbH (TMG), is a fully-owned and controlled entity of Toyota Motor Corporation, based in Cologne, Germany, which provides motorsport and automotiv ...
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
The
NASCAR Cup Series and
Xfinity Series
The NASCAR Xfinity Series (NXS) is a stock car racing series organized by NASCAR. It is promoted as NASCAR's second-tier circuit to the organization's top level Cup Series. NXS events are frequently held as a support race on the day prior to a ...
have mandated the use of restrictor plates at
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, the most prestigious race in NASCAR as well as its season opening event. In addition to NA ...
and
Talladega Superspeedway
Talladega Superspeedway, nicknamed “'Dega”, and formerly named Alabama International Motor Speedway (AIMS) from 1969 to 1989, is a motorsports complex located north of Talladega, Alabama. It is located on the former Anniston Air Force Base ...
since 1988, and until the
2019 Daytona 500 for Cup Series only. The plates were put into use in 1988 as a result of a wreck in the
1987 Winston 500 at Talladega that involved the car of
Bobby Allison
Robert Arthur Allison (born December 3, 1937) is a former American professional stock car racing driver and owner. Allison was the founder of the Alabama Gang, a group of drivers based in Hueytown, Alabama, where there were abundant short tracks ...
crashing into the frontstretch catch fence at a high enough speed to destroy almost 100 feet of the fence and put the race under a red flag condition for two hours. The following race at Talladega that year would be run with a smaller carburetor, however, NASCAR mandated the use of the restrictor plate at the end of the season.
The restrictions are in the interest of driver and fan safety because speeds higher than the 190 mph range used for Daytona and Talladega risk cars turning over through sheer aerodynamic forces alone. The severity of crashes at higher speeds is also much greater, shown by telemetry readings of wrecks such as
Elliott Sadler
Elliott William Barnes Sadler (born April 30, 1975) is an American former professional stock car racing driver. He last competed part-time in the NASCAR Xfinity Series, driving the No. 10 Chevrolet Camaro for Kaulig Racing. Sadler is one of 36 dr ...
at
Pocono Raceway
Pocono Raceway (formerly Pocono International Raceway), also known as ''The Tricky Triangle'', is a superspeedway located in the Pocono Mountains in Long Pond, Pennsylvania. It is the site of three NASCAR national series races and an ARCA M ...
and
Michael McDowell at
Texas Motor Speedway
Texas Motor Speedway is a speedway located in the northernmost portion of the U.S. city of Fort Worth, Texas – the portion located in Denton County, Texas. The reconfigured track measures with banked 20° in turns 1 and 2 and banked 24 ...
that were far higher than registered on restrictor plate tracks. Drivers such as
Rusty Wallace
Russell William "Rusty" Wallace Jr. (born August 14, 1956) is an American former NASCAR racing driver. He has won the 1984 NASCAR Cup series Rookie of the Year and the 1989 NASCAR Winston Cup Championship. Over the course of his successful care ...
have cited data showing that the
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. The flaps are stowed during normal vehicle operation; however, in certain situation ...
s used on the cars cannot keep them on the ground above 204 mph.
The drawback to the use of the restrictor plates has been the increased size of packs of cars caused by the decreased power coupled with the drag the vehicles naturally produce. At Daytona and Talladega, most races are marred by at least one wreck, usually referred to as
"the Big One", as cars rarely become separated. Talladega has been considered the more likely track for these instances to occur as the track is incredibly wide, enough to have three to four distinct lines of cars running side by side. With the new pavement at Daytona, three-wide racing became far easier, and multi-car wrecks became more common. The 2011
Daytona 500 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 was the last complete Cup season with carbureted engines; at the end of the 2011 season, NASCAR announced that it would change to an electronic fuel injection system for the 2012 racing season. The injection system used by NASCAR is a different system from that used in
IndyCar Racing
''IndyCar Racing'' is a racing video game by Papyrus Design Group released in 1993. Papyrus, consisting of David Kaemmer and Omar Khudari, previously developed '' Indianapolis 500: The Simulation'', released in 1989.
The game was intended as a ...
and other motorsports series; the EFI system that NASCAR put into use was compatible with the old restrictor plates, allowing NASCAR to continue to use them to keep the speeds lower at the superspeedways and save costs for race teams. The restrictor plates were bolted beneath a throttle body that sits in the same place as the former carburetors.
The last race with the original restrictor plates was the
2019 Daytona 500; after that race, the cars moved to a variable-sized tapered spacer already used at all other tracks, with the exception that the spacer would have smaller holes than the ones used at the smaller tracks, to ensure speeds stay under 200 mph. The shape of the spacer helps a car funnel more air smoothly into the manifold, increasing fuel performance, while ensuring airflow is still restricted. With that change, NASCAR also mandated the use of larger rear spoilers, larger front splitters, and specially-placed front end aero ducts. The combination of those features increased drag on the cars, counteracting the increased horsepower, keeping the cars close to the speeds they were running prior to the switch to the tapered spacer. While the racing quality noticeably improved, and passing was made easier with larger horsepower and bigger runs, speeds also noticeably increased past mph, and even into 205 mph ranges.
Starting in 2022, restrictor plate rules will be used for
Atlanta Motor Speedway
Atlanta Motor Speedway (formerly known Atlanta International Raceway from 1960 to 1990) is a 1.54-mile entertainment facility in Hampton, Georgia, United States, 20 miles (32 km) south of Atlanta. It has annually hosted NASCAR Cup Series ...
because of concerns over speed after the circuit was repaved and reconfigured to 28 degree banking.
Reason for restrictor plates
There have been four eras that
NASCAR
The National Association for Stock Car Auto Racing, LLC (NASCAR) is an American auto racing sanctioning and operating company that is best known for stock car racing. The privately owned company was founded by Bill France Sr. in 1948, and hi ...
used restrictor plates.
The first use came in 1970 as part of a transition from the seven-litre era (430 cubic inch) to the six-litre era (366 cubic inch) engine. Following testing and input from drivers such as
David Pearson,
Bobby Isaac
Robert Vance Isaac (August 1, 1932 – August 14, 1977) was an American stock car racing driver. Isaac made his first NASCAR appearance in 1961, and quickly forged a reputation of one of the toughest competitors of the 1960s and 1970s. He was most ...
, and
Bobby Allison
Robert Arthur Allison (born December 3, 1937) is a former American professional stock car racing driver and owner. Allison was the founder of the Alabama Gang, a group of drivers based in Hueytown, Alabama, where there were abundant short tracks ...
, NASCAR mandated the use of a restrictor plate for the big block seven-litre engines. Small block engines, in the 366 cubic inch range, were exempt from the plates; the first car to race with a small block engine was
Dick Brooks
Richard Brooks (April 14, 1942 – February 1, 2006) was an American NASCAR driver. Born in Porterville, California, he was the 1969 NASCAR Rookie of the Year, and went on to win the 1973 Talladega 500. Brooks held off veteran Buddy Baker b ...
at the
1971 Daytona 500, where he ran a 1969
Dodge Daytona
The Dodge Daytona is an automobile which was produced by the Chrysler Corporation under their Dodge division from 1984 until 1993. It was a front-wheel drive hatchback based on the Chrysler G platform, which was derived from the Chrysler K platfo ...
with a 305 CID engine. The transition period lasted until 1975, when the current 358 cubic inch (5870cc) limit was imposed. 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
Robert Arthur Allison (born December 3, 1937) is a former American professional stock car racing driver and owner. Allison was the founder of the Alabama Gang, a group of drivers based in Hueytown, Alabama, where there were abundant short tracks ...
at the
1987 Winston 500 at
Talladega Superspeedway
Talladega Superspeedway, nicknamed “'Dega”, and formerly named Alabama International Motor Speedway (AIMS) from 1969 to 1989, is a motorsports complex located north of Talladega, Alabama. It is located on the former Anniston Air Force Base ...
. Allison's
Buick LeSabre
The Buick LeSabre is a full-size car made by the division Buick of General Motors from 1959 until 2005. Prior to 1959, this position had been retained by the full-size Buick Special model (1936–58). The "LeSabre", which is French for "the sa ...
blew a tire going into the tri-oval at , spun around and became airborne, flying tail-first into the catch fencing.
"Top 10 NASCAR Crashes That Changed Racing (With Videos!)"
''Popular Mechanics'' (retrieved 10 Aug 2010) While the car did not enter the grandstands it tore down nearly 100 feet of fencing and flying debris injured several spectators. After a summer where the two subsequent superspeedway races were run with smaller carburetors (390 cubic feet per minute (cfm) instead of 830 cfm) 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 refers to the city of Daytona Beach, Florida, or things named after it.
Daytona may also refer to:
Locations
* Daytona Beach Shores, Florida
* South Daytona, Florida
* The Daytona Beach metropolitan area
* Halifax area, also known as Da ...
for all NASCAR-sanctioned races and Talladega for Cup races. The Automobile Racing Club of America
The Automobile Racing Club of America (ARCA) is an auto racing sanctioning body in the United States, founded in 1953 by John Marcum. The current president of ARCA is Ron Drager, who took over the position in 1996 following the death of Bob Log ...
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.
NASCAR's concerns with speeds because of power-to-weight ratios result in restrictor plates at other tracks. The Goody's Dash Series
The ISCARS Dash Touring Series (previously known as the NASCAR Baby Grand National, Goody's Dash Series and IPOWER Dash Series among others) was a stock car racing series created by NASCAR in 1973, initially running solely at North Wilkesboro Sp ...
(known now as the ISCARS series with its new ownership) used restrictor plates at Bristol
Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
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 were not initially used for Camping World Truck Series trucks. Rather, aerodynamic air intake reduction through the use of a 390 cfm carburetor, and eventually a tapered carburetor spacer were implemented for those races. Combined with the aerodynamic disadvantage of the trucks, this allowed NASCAR to avoid the use of such equipment for the trucks until 2008. In 2008, the Nationwide Series (now known as Xfinity 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. Both these NASCAR series now use a restrictor plate and tapered spacer at the two tracks.
The third use came in 2000. Following fatal crashes of Adam Petty
Adam Kyler Petty (July 10, 1980 – May 12, 2000) was an American professional stock car racing driver. He was the fourth generation from the Petty family to drive in races in the highest division of NASCAR racing, mostly in what was then kno ...
and Kenny Irwin Jr.
Kenneth Dale Irwin Jr. (August 5, 1969 – July 7, 2000) was an American stock car racing driver. He had driven in all three NASCAR national touring series, and had two total victories, both in the Craftsman Truck Series (today Camping World Tru ...
at the New Hampshire International Speedway
New Hampshire Motor Speedway is a oval speedway located in Loudon, New Hampshire, which has hosted NASCAR racing annually since 1990, as well as the longest-running motorcycle race in North America, the Loudon Classic. Nicknamed "The Magic Mil ...
during the May Busch Series
The NASCAR Xfinity Series (NXS) is a stock car racing series organized by NASCAR. It is promoted as NASCAR's second-tier circuit to the organization's top level Cup Series. NXS events are frequently held as a support race on the day prior to a ...
and July Winston Cup Series
The NASCAR Cup Series is the top racing series of the National Association for Stock Car Auto Racing (NASCAR). The series began in 1949 as the Strictly Stock Division, and from 1950 to 1970 it was known as the Grand National Division. In 1971 ...
races, respectively, NASCAR adopted 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 300. Jeff Burton
Jeffrey Tyler Burton (born June 29, 1967), nicknamed The Mayor, is an American former professional stock car racing driver and current racing commentator. He scored 21 career victories in the NASCAR Cup Series, including two Coca-Cola 600s in ...
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 Andrew Andretti (March 12, 1963January 30, 2020) was an American race car driver. He won individual races in CART, IMSA GTP, Rolex Sports Car Series, and NASCAR during his career. He was the son of Aldo Andretti, older brother of racer Adam ...
(who finished seventh), and two charges by Bobby Labonte
Robert Allen Labonte (born May 8, 1964) is an American semi-retired professional stock car racing driver and current analyst for ''NASCAR on Fox''. He also currently competes full-time in the Superstar Racing Experience, driving the No. 18 car. L ...
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 SAFER Barriers to improve racing safety. Restrictor plates remain a permanent fixture on the Modifieds and the racing has often broken 20 official lead changes for 100–125 laps of competition.
Rusty Wallace
Russell William "Rusty" Wallace Jr. (born August 14, 1956) is an American former NASCAR racing driver. He has won the 1984 NASCAR Cup series Rookie of the Year and the 1989 NASCAR Winston Cup Championship. Over the course of his successful care ...
tested a car at Talladega Superspeedway
Talladega Superspeedway, nicknamed “'Dega”, and formerly named Alabama International Motor Speedway (AIMS) from 1969 to 1989, is a motorsports complex located north of Talladega, Alabama. It is located on the former Anniston Air Force Base ...
without a restrictor plate in 2004, reaching a top speed of in the backstretch and a one-lap average of .[NASCAR.com – Rusty Wallace hits 228 mph in Talladega trial – June 10, 2004](_blank)
/ref> 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."
In 2016, following a series of uncompetitive races at Indianapolis Motor Speedway
The Indianapolis Motor Speedway is an automobile racing circuit located in Speedway, Indiana, an enclave suburb of Indianapolis, Indiana. It is the home of the Indianapolis 500 and the Verizon 200, and and formerly the home of the United State ...
, NASCAR began a series of tests for the Xfinity Series using a smaller restrictor plate than used at Daytona and Talladega and aerodynamic aids. After the tests were successful, the rules package was imposed for the 2017 race at Indianapolis. For 2018, the package is being used at Indianapolis, Michigan, and Pocono for the Xfinity Series and in the All-Star Race in the Cup Series.
The competitive quality of restrictor plate racing
A frequent criticism of restrictor plates is the enormous size 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 Superspeedway
Talladega Superspeedway, nicknamed “'Dega”, and formerly named Alabama International Motor Speedway (AIMS) from 1969 to 1989, is a motorsports complex located north of Talladega, Alabama. It is located on the former Anniston Air Force Base ...
the Sprint Cup cars have surpassed 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 had 88 lead changes, but the 88th – the race-winning pass by Kevin Harvick
Kevin Michael Harvick (born December 8, 1975) is an American professional stock car racing driver. He competes full-time in the NASCAR Cup Series, driving the No. 4 Ford Mustang for Stewart-Haas Racing.
Harvick is the 2014 Cup Series champio ...
– was on the last lap of the third attempt at a green-white-checkered finish). 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, the most prestigious race in NASCAR as well as its season opening event. In addition to NA ...
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
The ARCA Menards Series East (formerly Busch East Series, Busch North Series, Camping World East Series, and NASCAR K&N Pro Series East) is a regional stock car racing series owned and operated by the Automobile Racing Club of America (ARCA) and ...
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, 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
Robert Arthur Allison (born December 3, 1937) is a former American professional stock car racing driver and owner. Allison was the founder of the Alabama Gang, a group of drivers based in Hueytown, Alabama, where there were abundant short tracks ...
, Darrell Waltrip, Neil Bonnett, and Buddy Baker.
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 transitional years (1971–76) where the seven-litre engines (430 cu in) had restrictor plates, Daytona and Talladega broke 40 official lead changes six times, while Michigan International Speedway
Michigan International Speedway (MIS) is a moderate-banked D-shaped speedway located off U.S. Highway 12 on more than approximately south of the village of Brooklyn, in the scenic Irish Hills area of southeastern Michigan. The track ...
broke 35 official lead changes in both of its 1971 races.
References
{{reflist
Engine technology
Auto racing equipment