The NASCAR Vehicle

->section of fence at the Talladega Speedway in
The original concept of a NASCAR race car was thatTalledega, Alabama. Fans were injured in the stands
is was supposed to be composed of stockand NASCAR took action to restrict the speed of
parts-parts you would buy in an auto parts store. Inthe vehicle through what is known as a restrictor
some respects that is true but not totally. The raceplate. This also gave birth to the term
car is a high performance racing machine designed to"restrictor-plate racing."
withstand high G-forces when banking on turns. Let'sThe physics of the restrictor plate have to do with
look at what makes up this vehicle.reducing air intake into the intake manifold of the
The first component most are interested in is theengine. Less air will result in lower combustion thus
engine of a NASCAR racing vehicle. This enginereducing horsepower. The restrictor plate is a sheet
actually is very close to that which you have in yourof metal with four holes bored in it at precise
car (provided you have a big engine) but it istolerances. The plate is then mounted between the
customized so that it can withstand high temperatureintake manifold and the carburetor. After that, the
and torque. All parts in the engine of a are machinedNASCAR vehicle should not be able to exceed
to within very tight specifications so that there is aspeeds of 200 mph.
minimum of friction. The carburetor is designed to letIt would seem like the restrictor plate would resolve
in the volume of air and fuel mixture required tothe safety problem but many professional drivers
sustain high speeds for lengthy spans of time. Therehave been asserting that it creates more potentially
are no fuel injectors in the race cars engine.unsafe situations in a race. If you think about the
The first modification to the NASCAR vehicle was todifference between a motor scooter and a
smooth out the ride. Early races were run on tracksmotorcycle you can see where a restrictor plate
that were very bumpy and this causes a lot ofcould create problems. Many times a motor scooter
damage. Today, the NASCAR vehicle is basically ahas an accident where a motorcycle could have
body molded from sheet metal on a frameavoided it because of its increased ability to
supported on the inside by bars made of sheetaccelerate (a motorcycle can accelerate quicker to
tubing. The vehicle is not a stock vehicle any longeravoid an oncoming threat). It is the same complaint
as each component is hand-crafted and assembled.among almost all of the racers with restrictor plates.
The car is built with safety in mind while giving it theThey have identified situations where the cars bunch
ability to maintain speeds approaching 200 mph. Driverup and the driver only has one choice and that is to
comfort is not the focus.slow down. Speeding up to avoid the congestion is
The NASCAR vehicle at one time was able to reachnot an option because the other cars may be at the
speeds in excess of 200 mph and that all changed inrestrictor plate limit too.
1987 when Bobby Allison's race car flew into a