NASCAR cars chassis and body.
Chassis, body and cockpit.
When NASCAR was created at the end of the forties, the strictly stock rule implied that the frames of the cars used in racing were identical to those one could buy from the dealer. Today's frames are fabricated from welded steel tubing which guarantee a very high level of safety.
The usage of the "cage" was introduced by companies such as Banjo Center Performance and Hutcherson-Pagan at the beginning of the Sixties, after several pilots were killed in accidents. The first company was founded by Banjo Matthews who became one of the most famous body manufacturers after he retired from his racing career. Nowadays, Hutcherson Pagan, Laughlin Racing Products and Ronny
Hopkins Race Bus produce more than 80% of the car body used in Winston cup.
The cage:
It consists of an assembly of welded steel tubes reinforced by gussets at many of their crossing
points. The role of the cage is to support the body panels, but also to protect the pilot during an accident. Its dimensions are regulated by NASCAR. Today, cage manufacturing techniques are so good that drivers leave unhurt from the most spectacular crashes, where what is left of the car is nothing more than a pile of scrap metal.
The chassis:
The following step is the construction of the frame, also made out of welded tubing. It is built according to the tracks on which the car is intended to run. The majority of the Winston cup teams have at least two cars with different frames to cover the various tracks. The less whealthy teams have their frame made for the tracks on which their driver is the most at ease and... do their best on
the others.
Steel is used for all the parts, since the weight of the frame is of relatively small importance. Indeed, NASCAR imposes a minimum weight of 3400 pounds (1511 kg) for a race-ready Winston cup car. This allows using off-the-shelf and cheap materials and traditional welding techniques. By comparison, Formula 1 cars mostly use aluminium, a more expensive material, more difficult to work and weld.
A meticulous care is taken to cut the tubes at perfect angles and weld perfect seams. Many reinforcement points are added at critical places, such as the corners supporting the roof and at the junction of the cage and the chassis.
Qualitywise, these frames are comparable to "masterpieces" formerly manufactured by the "companions". The only difference: the companions were not payed for their job, whereas a Winston cup frame sells for approximately $8000, to which another $8000 must be added for the body.
This is only a fraction of the total cost of a car.
Some details:
Manufacturing a frame requires 150 ft of steel tubing, 40 ft of 2" x 3", 12 ft of 3" x 4 " and 120 sqft of sheet metal. More than five hundred working hours are necessary for tube cutting, welding and sheet metal work. The companies who manufacture these frames use templates and prepare parts for ten cars simultaneously.
Inside the cockpit:
The interior is Spartan but the functionality is omnipresent. No electronic display like in Formula 1 here, NASCAR forbids it. All indicators must be analog (with a needle). The steering wheel is detachable, allowing an easier access to the pilot.
No speedometer either, it would be redundant with the tachometer, which is more precise anyway. The instrument panel also lacks a fuel gauge, replaced by a device which detects a drop in the fuel pressure at the carburetor intake. When the pressure starts fluctuating, it is time to call the pit crew to require a refill. In practice, the crew chief calculates the fuel consumption and warns the pilot of the situation well before its indicator.
At 200 mph, a split second glance must suffice to know the general state of the major componenent: oil pressure, engine speed, alternator voltage, engine temperature.
All indicators are designed so that the needle in vertical position indicates normality. This is also true for the tachometer, which can be oriented to read the optimum engine speed "at noon", 7000 rpm in the picture on the left. Winston cup cars are adjusted to indicate 8000-9000 rpm.
No ignition key can be found, a series of switches (on the left on the picture) controls the starter and the ignition. A back-up ignition box can be switched on by the driver in case the first one fails. This happened to Dale Earnhart during the 1999 Daytona 500 and allowed him to finish in 2nd place.
The driver seat is extremely rigid and made out of reinforced aluminium, doubled with minimal padding.
The driver's legs are maintained on the sides not to slip in the turns and tire the pilot. The safety straps are attached to the seat frame, itself bolted to the frame.
The oil radiator is usually fixed behind the driver and cooled by air intakes placed
in the Lexan (polycarbonate) rear "windows". This may appear as a strange location, but the engine compartment is in practice exclusively reserved for the radiator, while the cockpit provides both protection and fresh air intake. Unfortunately, this also causes a raise in the cockpit inside temperature, sometimes up to 60°C (140°F). To compensate for this effect, an additional air intake sends fresh air directly in the driver's helmet through a flexible connection.
The left front window is also the access for the driver. It is replaced by a removable net which protects the pilot against debris during a race or in an accident.
The rear view mirror (approved by NASCAR) is designed in three sections showing the cars on the left, on the right and behind. Moreover, the rear view mirror is supplemented by the spotter, located on the top of the control tower. The spotter gives the driver information on the surrounding cars and on what happens on the track (incidents, debris, etc...).
Textes: © Jean Bizouard, 1999-2000.
[Detail: Kevin Thorne for Racing Milestones (03/99)],
[Chassis:Doug Gore for Stock Car Racing Magazine (03/98)].
