Sunday 8 March 2015

Electric Motors Weaponized for Motorsports




HotRod.com: The time has come when we can no longer ignore electric motors as a performance option. Sound far-fetched? It used to be, but it’s hard to argue with the recent developments electric power has gone through—in fact, electric motors are stealing from our playbook.

[01] McLaren’s 270hp Formula E electric motor only weighs 57 pounds. This massive weight reduction over normal electric motors makes this powerplant one of the highest power-to-weight ratio motors in the world. For energy savings, drivers are limited to approximately 202.5 hp during race laps.

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[02] The energy required to run lap after lap on electricity is enormous, which is why 441 pounds worth of Williams’ battery (WilliamsF1.com) cells capable of 1,000 volts are installed into each car.

[03] Charging time is still nearly an hour at 800 volts, so after 25 to 30 minutes of racing, drivers simply jump into a second, fully charged car during a 30-second “pit stop.”

[04] These electric motors have the ability to turn at speeds of up to 17,500 rpm (with a “current cut” at 18,000 rpm), so a traditional Hewland five-speed paddle-shift gearbox is used. With torque levels of 170 lb-ft starting at 0 rpm, more speeds aren’t needed. Also not needed is a clutch, as the electric motor is connected directly to the transmission.

[05] The electric motor can actually be used as additional rear braking under deceleration, giving the Formula E cars essentially two braking systems. During a race, the motor is used as much as possible, as energy regained during braking can then be used during acceleration.
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[06] Energy expenditure is limited to 28-kilowatt hours (kWh) per race, so drivers must also conserve power as much as possible to finish the race. Switches are installed in each car where drivers can turn their maximum power up or down based upon their own energy use.

[07] Formula E cars have a cooling system, just like gas-powered F1 race cars. Twin radiators in side pods are used to cool both the electric motor and controller to keep them from overheating.

[08] Formula E cars produce approximately 80 decibels (dB) during a drive by, as opposed to the ear-shattering 135 dB that F1 cars produce. Normal freeway noise comes in at about 77 dB.

Hot rodders have always been all about power-to-weight ratios, and at a peak of 270 hp and 1,957 pounds, the Spark-Renault SRT_01E or FIA Formula E cars (shown here) are extremely capable performance machines with impressive stats of 0–60-mph times in 3 seconds flat, easily able to reach their governed speed of 140 mph. More important than the horsepower, however, is that the range of these cars is extended far beyond the scope of previous electric race vehicles. While racing purists may scoff at electric cars quietly whooshing around a track, there is impressive technology involved in building such machines. Check your local listings to view the Formula E series on TV or visit FIAformulae.com for more information.
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Who Makes Electric Race Parts?

Where do you go to find an electric drivetrain for a race car? Much of the technology is proprietary (think high-voltage Mystery Motor), but if you’re looking for new powerplant or motor control unit technology, check out:

McLaren, MclarenElectronics.com

Williams, WilliamsF1.com

Yasa Motors, YasaMotors.com



Read more: http://www.hotrod.com/features/1504-electric-motors-weaponized-for-motorsports/#ixzz3TmU5YWn3
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