Champ Car World Series : Technical Specs

A-arms

A component of suspension, these metal rods connect the tires and wheels to the chassis.  They are usually shaped like an "A", with the point of the A connected to the wheel and the bottom two points of the A connected to the chassis.  There are usually two A-arms at each wheel, one top and bottom. Also called wishbones.

Aerodynamics

The science of managing airflow over, under and around a car plays a major role in Champ Car design and tuning. Areas of high and low pressure are carefully managed to maximize downforce (to help the tires grip the ground) while minimizing drag (to maximize speed). Two principal concepts are used to achieve these goals. Front and rear wing work like upside-down versions of an airplane wing, pressing the car downward. Also, the bottom of the car features a special underbody that includes two large grooves (like funnels cut in half) called tunnels that suck the car down by creating a partial vacuum underneath called ground effects. The use of wind tunnels play a key role in Champ Car design and evolution.

Air (dirty or clean)

As a specialized aerodynamic device, a Champ Car must be designed and tuned to work well when conditions are not ideal. If a car is travelling around a track by itself (such as in oval track qualifying), the air is undisturbed and is considered "clean". However, each car throws off a significant amount of turbulence in its wake, much like the waves and bubbles created by a moving boat. If a car travelling behind another car is affected by this turbulence, the air is considered "dirty". Careful attention must be paid to tuning the aerodynamics so that the car works well in both "clean" and "dirty" conditions.

Air pressure

Mechanics can adjust a car's handling by raising or lowering air pressure in the tires. Flex in the sidewall acts like another spring in the suspension. Increasing the air pressure makes the overall spring rate stiffer, while lowering the pressure will make it softer.

Anti-roll bars

A mechanical linkage, one each for the front and rear suspensions, that helps transfer more weight to the inside tires in the corners and helps keep all four tires gripping the track. The driver adjusts the anti-roll bars with levers in the cockpit. Also called a sway bar.

Bodywork

The exterior of the car. The bodywork is generally made from carbon fiber. The panels lift off in sections so mechanics can get to mechanical components easily and quickly. Bodywork is carefully sculpted to maximize aerodynamic efficiency. Boost The engine on a Champ Car gets added power from a turbo attached to the engine. The turbo provides boost to the intake manifold pressure, increasing the amount of fuel and air that get packed into the cylinders and providing greater power output. Boost pressure is adjustable by the driver, who tries to maintain the maximum amount of intake pressure while not triggering the pop off valve causing a loss of power. Carbon fiber Carbon fiber is lighter than aluminum, stronger than steel, and very expensive material. It's used to construct the chassis of a modern Champ Car. Sheets of carbon fiber cloth are "laid up" like fiberglass by an expert fabricator using a mold, and then heated and reheated for days in an autoclave, a large, high-tech oven. Chassis The basic structure of a car, including the driver tub, gearbox and suspension. Engines are provided separately by Ford Motor Company. There is only one chassis manufacturers in Champ Car, the Panoz DP01 built by Elan Motorsports, which is based in England. Chassis Roll As a car goes through a corner, G forces cause the chassis to want to continue going straight. Since the tires are gripping the pavement at the very lowest point on the car, the upper part of the car tends to lean outwards in the corner. The way chassis roll affects handling can be adjusted by making changes to the suspension, raising or lowering the roll center front and rear. ECU - Engine Control Unit The engine control unit in a Champ Car is a more sophisticated version of the computer in a street car, controlling functions such as ignition timing and fuel metering. In a Champ Car, the functions include traction control and driver-controlled fuel adjustment., and can be set up so that the engine will run at different maximum RPM limits or traction control settings depending on which gear the car is in or even location on a race track. An ECU can be easily reprogrammed by connecting a laptop computer to a plug on the side of the car. Engine Champ Cars use Ford engines prepared and tuned by Cosworth. These tiny engines are 2.65-liter overhead-cam turbocharged V-8s producing approximately 950 horsepower, running on methanol fuel. Champ Cars can reach speeds over 220 Mph.   G Force The inertial force exerted upon drivers as the car changes direction. One "G" is equal to the force of gravity. Inertia causes a moving object to try and keep the same speed and direction of travel. As a Champ Car races around the track, any change in direction creates some amount of G Force. There are six directions of G Force: left/right, front/back and up/down. High-speed corners exert more G force on drivers than do very slow corners due to the additional grip provided by down force as speeds increase, but braking, acceleration and rises or drops in the pavement also create "G"s. Champ Car drivers often endure up to five "G"s, or five times the force of gravity, particularly on high-speed oval tracks where banking in the turns create a combination of lateral (left/right) and vertical (up/down) G forces. Pop-off valve Champ Car engines are currently turbocharged providing additional horsepower and torque by injecting air and fuel into the engine's intake manifold under pressure. Champ Car limits the amount of pressure, or "boost", which can be used in order to help keep horsepower within reasonable limits. To keep the playing field even (and the manifold pressures within the rules), Champ Car provides each team with a manifold pressure relief, or pop-off valve, to put on top of their intake manifold. It's called a pop-off valve because it makes a loud pop when it lets off excess pressure. The effect is a sudden drop in horsepower. Champ Car jealously guards these valves, and goes to great lengths to make sure they are both accurate and consistent. Each day of practice, qualifying and racing, Champ Car officials pass out the pop-off valves to the teams and collect them in the evening.

CHAMP CAR ELECTRONICS:

The Electronics

A Champ Car is essentially a rolling computer. On both of the air tunnels for the radiators you will find an assortment of many different electronic subsystems.

For example, in the photo below (the driver's left) you can see:

• The data logging computer
• The engine control unit (ECU), which is another computer
• The alternator control electronics
• The battery for all of the on-board electronics (it is the long box mounted along the side of the pod)

Champ Car Electronics pic - 1  Side Pod

Champ Car Electronics pic 2 - Drivers Left

The role of the computer has grown significantly over the last 10 years. The engine is now completely controlled by computer (if this computer goes out, the engine will not run). Among other things, the ECU controls:

• Ignition
• Fuel mixture
• Timing
• SWOL ("Shift Without Lift" allows the driver to shift without coming off the throttle)
• Speed control (for example, in the pits)

Each team outfits its car with a sophisticated data logging system called (SYGMA) as well as a telemetry system able to transmit data from the car to the pits in real-time. Each team has at least one member affectionately known as the DAG -- the Data Analysis Generator -- whose specific role is to pore over the reams of data a car produces during a practice run or a race and help the team use that data to maximize the car's performance.

A typical data-logging computer is capable of measuring 200 different parameters of the car while the car is in motion. The data logging system can also transmit 72 channels of data back to the pits in real-time. All 200 parameters are also stored onboard for later downloading. The team can connect a laptop to this jack, located under the rollbar, to download the car's stored data into a laptop computer:

Data port for laptop computer on a Champ Car