CHAMPCAR/CART: Electronic Nervous System of a Champ car

The Electronic Nervous System of a Champ Car Wiring Looms Carry Data at Speed of Light Part Two of a Four-Part Series Relating Racing Electronics to the Human Body DETROIT (July 27, 1998) -- Race cars have a brain that communicates through...

The Electronic Nervous System of a Champ Car Wiring Looms Carry Data at Speed of Light

Part Two of a Four-Part Series Relating Racing Electronics to the Human Body

DETROIT (July 27, 1998) -- Race cars have a brain that communicates through wires similar to the way the human brain communicates through the nervous system.

The Magneti Marelli engine control unit (ECU), the brain of the Mercedes-Benz IC108E Champ car engine, communicates through its own electronic nervous system, which is called a wiring loom.

"Our wiring looms are a lightweight version of wiring used in aerospace and military applications," said Jonathan Kirkland, electrical department manager for Ilmor Engineering in Brixworth, England, the race-engine design and manufacturing arm of Mercedes-Benz. "They are designed to resist heat of 200 degrees centigrade (nearly 400 degrees Fahrenheit), as well as corrosion from fuel and oil."

There is 1,600 feet of wire - more than one-quarter mile -– in one complete loom. Inside, information travels between the ECU and the other components of the Marelli electronics and fuel management system at the speed of light-– which is approximately 180,000 miles per second, said Kirkland.

That is much faster than the human body’s nervous system, which at its fastest carries information between the brain and vital organs at a comparably slow 100 meters per second, or 225 mph. Spinal Cord

Just like the human body, the electronic nervous system of a Champ car has a sort of protected "spinal cord." The main junction of the wiring loom includes more than 200 wires inside a tube made of Elastomeric material (high-tech plastic) which is heat-shrunk around the wiring for added protection, said Paul Sharp, who handles the prototype wiring on all of Ilmor’s racing engines. In turn, each of the wires have their own protective coating of Polyvinylidene Fluoride material, which is also similar to plastic.

All this protection is necessary since the electronic nervous system carries millions of bits of information every second. This is possible due to the fact that the wires in the loom are capable of multi-tasking.

Multi-Tasking

"Multi-tasking means one wire can carry a lot of signals back and forth at one time," said Sharp. "The new Marelli components are a great deal faster and carry more information than the previous electronics system, so having wires that can handle large amounts of data faster is essential. Multi-tasking is the only way the loom can handle all that information.

"For example, with the previous system we had 16 wires feeding the buttons on the steering wheel. With the Marelli system, we have a single pair of wires feeding the steering wheel that is packed with Marelli electronic controls and displays. Thanks to multi-tasking, the entire loom is smaller and lighter all around. Less wires makes our job easier."

It takes 140 man-hours to assemble one multi-tasking loom. Ilmor has a staff of 10 who design and manufacture custom looms for the five teams and eight drivers using both the Penske and Reynard chassis in the CART FedEx Championship Series.

Left-Brained/Right-Brained

"The looms for the 1998 Penske are slightly different from the looms for the 1998 Reynard, because the electronic components are located in different places on those two cars," said Sharp. "On the Reynard, the ECU and other components are on the left side-pod. On the Penske, the electronics are on the right side-pod."

That must mean that the Reynard is left-brained, while the Penske is right-brained.

Based in Milan, Magneti Marelli is an international supplier of automotive components and systems, including: engine control systems, instrument panels, air conditioning systems, lighting, fuel delivery systems, mirrors, exhaust systems, mechanical and electronic components, shock absorbers and lubricants. In addition to Mercedes-Benz, Marelli’s clients include Chrysler, Ferrari, Fiat, Ford, General Motors and Harley-Davidson, contributing to combined worldwide sales of more than $3.9 billion.

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Series IndyCar