(May 13, 2009) This weekend Corsa Motorsports will take up the American Le Mans Series' (ALMS) Green Challenge when it debuts the first hybrid race car in ten years and only the second in series history. The Ginetta-Zytek 09HS LMP1 was developed in conjunction with British engineering services company Zytek. Along with race engineering and powertrain manufacturing, Zytek has worked several automakers on hybrid systems development.

The last hybrid racer in the ALMS was the Panoz Q9 which Zytek also hand in when it debuted during the 1998 season. The Panoz was only raced twice, at the 24 Hours of Le Mans in France and then later at the Petit Le Mans in Georgia. The project was sidelined for a decade until Corsa and Zytek teamed up in early 2008 after a phone call between Corsa driver Johnny Mowlem and Zytek's Bill Gibson. In spite of a lack of a major sponsor or factory support, Corsa team owner Steve Pruitt decided that the opportunity to provide some homegrown development of both hybrid and battery technology was worth the investment in the program.

At the Detroit Grand Prix in August 2008, Corsa announced that it would make the switch from running Ferrari F430s in the GT2 class to running an LMP1 car with hybrid drive. Unfortunately getting the car ready to run proved more difficult than anticipated and the October debut at the Petit Le Mans was pushed back to March 2009 at Sebring and then to this week's race in Utah. The car finally arrived in the United States this week following a shakedown run in England last week.

Prior to the car actually being completed and testing the Zytek engineers have spent several years developing the powertrain using computer simulations and then dynamometer testing.

Mowlem and Pruitt both spoke with Green Fuels Forecast about the new car prior to the start of practice for the Utah race. According to Pruitt, the team is pursuing the hybrid powertrain for a number of reasons. With the rules set by the Automobile Club de l'Ouest (ACO) encouraging the use of alternative powertrains and the American Le Mans Series actively pushing green racing through this year's Michelin X Green Challenge, it made sense to try something. Pruitt is also a proponent of developing energy independence for the United States and sees this as one of the paths to achieving that.

The hybrid drive system consists of an electric motor/generator sandwiched between the engine and gearbox that combined with a clutch mechanism creates parallel power paths for the electric and internal combustion sources. The motor can put out between 35 and 45 kW and Mowlem tells GFF that the torque is so immense that the electronic controls have to artificially limit it to prevent shredding the tires prematurely.

As in road-going hybrids the motor/generator provides both power boost and regenerative braking capabilities. The kinetic energy captured during regenerative braking is converted to electrical energy and stored in a 140V lithium ion battery pack. The pack is supplied by Continental and is similar to the one that will be used in the production Mercedes-Benz S400 mild hybrid beginning later this summer. During the Silverstone shake down run, Mowlem tells GFF that the car was run with the electric drive disabled and also with electric drive only. In electric drive mode, the car is virtually silent and Mowlen was able to complete a full lap of Silverstone without running the engine reaching a maximum speed of 75 mph from the 16,000 rpm motor.

One element the race car lacks that most road going hybrids have is a mechanism to automatically blend the friction and regenerative braking. Production hybrids use an electro-hydraulic brake system that gets a signal from the powertrain about how much regen braking is available, compares that with the driver demand from the brake pedal and then reduces the friction braking pressure accordingly. Like other race cars, the Ginetta-Zytek has a manual front-rear brake balance lever that the driver controls. The driver will have to judge the regen coming from the rear wheels and adjust the friction balance forward manually which will prove to be a real challenge under racing conditions.

In Formula One this year teams began using a hybrid drive system called Kinetic Energy Recovery System (KERS) that provides for some limited power boost. The rules currently allow for up to 6.5 seconds per lap of power boost from KERS with up to 80 kW of output. The extra energy is released by the drive with a steering wheel mounted button on demand.  Rather than an on-demand system the Corsa car uses the normal engine mapping switch on the steering wheel to select from pre-defined combinations of electric and internal combustion power.

When the Corsa program was originally announced, the hybrid car was also supposed to include a new 4.5-liter V8 to replace the current 4.0-liter unit. However, because there are still so many unknowns, the team has opted to stay with the known quantity engine until the hybrid system is better understood. Another element the team will eventually have to overcome is weight. The hybrid system adds enough mass to the car that according to Mowlem and Pruitt, it is close to the minimum weight of 975 kg for LMP1 cars without using any ballast.  Most race cars are built below the mininum weight for their classes which allows teams to use ballast to adjust the balance of the car depending on the track configuration and conditions. For now Corsa doesn't have that flexibility.

Because no one really knows what the benefit of the hybrid system used by Corsa will be the current ACO/IMSA rules do not limit the system.  Instead the sanctioning body will monitor the performance and make adjustments to the rules as needed based on the on-track performance.

Pruitt tells GFF that he has been talking with officials from the US Department of Energy to try and set up promotional programs with the race car. As the car goes around the country to various races, Pruitt will like to do public events to both encourage young people to become more aware and get involved in engineering as well promote the development of a domestic battery industry. He noted that the Chevrolet Volt will initially be powered by South Korean LG Chem lithium ion batteries. While there are several domestic battery makers including EnerDel and A123 Systems, the biggest chunk of work is being done overseas.

The Corsa Motorsports team has a tough road ahead and will have to put in a lot of long hours to make its new car work. If successful, they could be leading the way for a number of other manufacturers and teams in the increasingly popular ALMS.