When IndyCar vehicles motor around the track this year, microcontrollers are monitoring virtually every component, from the engine to the gearbox to the shock absorbers, but the conditions under which they can provide a competitive edge are being carefully controlled.
To contain costs and maintain relative parity among the cars, IndyCar declared this year that competitors are not allowed to tamper with the software code in the engine control unit (ECU) or the gearbox control unit (GCU). For the most part, the cars will run with the same electronic hardware and software.
"The rules now prevent us from getting into the ECU," Mark Johnson, general manager of KV Racing Technology, told us. "In years past, we had the latitude to work with the code, but we're not allowed to do that anymore."
IndyCar teams aren't allowed to tamper with the software code in the standardized Indy ECU.
Under the current rules, competitors must use one of three engines, all of which are limited to a V6 design with 2.2 liters of displacement. All three engine builders (Chevy, Honda, and Lotus) must employ ECUs from McLaren Group, which customizes the controllers for each engine. The software in the McLaren ECUs must also adhere to the turbocharger boost requirements, which change from race to race. "All of the boost for the turbos is electronically controlled," Johnson said. "If someone were able to get in and manipulate the boost, they could change the horsepower and change the outcome of the race. That's why there are tight stop gaps in the ECU to monitor that."
The electronic restrictions don't stop there. All race teams must use identical electronic modules built by the same supplier, Cosworth Group. The modules enable all the controllers inside the vehicle to talk to one another. Engines and gearboxes, for example, communicate via Cosworth electronics. Dashboards, steering wheels, data acquisition cards, and sensors also must employ the same hardware.
"The way it's set up, Cosworth is the only one that's constantly updating the software," Johnson said. "If Chevrolet has an update to its engine -- say, for example, it wants to change its fuel strategies -- then it has to be filtered through Cosworth. Cosworth has to integrate their changes into the system."
However, the new rules don't mean race team engineers have little to do. Most teams keep relatively big engineering staffs. KV, for example, has two electronics engineers, two data acquisition engineers, and a radio engineer. Those five are joined by two mechanical engineers, two simulation engineers, a vehicle dynamics engineer, an aerodynamics engineer, and a parts design engineer who also doubles as a draftsman.
Much of the staff's time is taken up by incorporating sensors on the car and then analyzing the data that comes from them. On race day, the team is allowed to monitor 32 channels of data, including wheel speed, bearing temperature, water temperature, oil temperature, brake rotor temperature, gearbox pressure, and aerodynamic pressures around the vehicle. Such monitoring may provide extra hundredths of a second at all the right times, potentially spelling the difference between victory and defeat.
"Even within all the rules, there's still plenty of electronic activity in the car," Johnson said. "The pulse of the car is built around the electronics."
[Learn more about IndyCar at Littelfuse's Speed2Design site.]