BigFoot goes electric

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The legendary BigFoot monster truck that started the monster craze has converted, turning over a new leaf.

The first monster truck and the recognized King of Monster Trucking is the BigFoot. The legendary truck was created by Bob Chandler and is the most-recognized name in monster truck arenas. When it was introduced, it became the first car-smashing celebrity pickup and over the years, while the truck has changed with the times, its car flattening prowess has not.

Now, despite electric cars seemingly being the exclusive property of the types of compact cars BigFoot normally obliterates in a show, the monster truck is turning over a new leaf.

Inspired in part by the Nissan Leaf electric car, which BigFoot's creator Chandler has seen in his home town of St. Louis, the BigFoot team decided to go green. After five weeks of work, working 7 days a week, the team converted the monster truck legend into another first: the first all-electric celebrity monster truck.

Yesterday, the team made a test run of the newly-converted beast and were pleased. "It's really, really quiet," said Chandler in an interview with local news station KPLR. "It kinds of sounds like a mad RC car."

The new BigFoot is running on 360 volts at 1400 amps powered by 36 batteries and a huge electric motor of unspecified size and power. While the team has not given a range for the new system, it's more than enough to power it through a full night's performance and can be easily topped off between highlights at the arena.

Modifications to the truck include changes to its drive lines, differential, and the addition of battery storage bays for weight distribution. Everything also has to be well-protected and shock proof, since the truck is expected to not only run over the top of cars, crushing them (with the resulting shrapnel often going upwards into the truck), but to leap and land from ramps and jump points. The team is confident after this initial test that the new BigFoot is ready for a full showing, sans the usual noise.

Not only will the audience be able to hear the crushing of cars and smashing of metal thanks to the absence of engine noise, but the driver and team will be able to hear the crowd's reaction as well. Although noise and power displays will always be a part of monster trucks, the changes BigFoot is introducing may bring in an entirely new aspect to the sport.

Submitted by Paul (not verified) on November 9, 2012 - 6:47PM

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They should have use 2 or 4 motors to provide AWD without differential linkages.
The motor they used must be huge with a high max power rating and very high power electrical system.

Using multiple motors would allow more torque while reducing the max power per motor.

They did not release details of the motor(s) being used. I went off of the photos they released of the chassis and powertrain, which appears to have only one very large motor (it's possible that's a case with two motors in-line) and drive shafts coming from a 2-way differential/transmission that didn't appear to have any gearing linkage, so I assume it's a power splitter/differential for the drive shafts going to the front and rear wheels.

Because of the high lift on the truck, the drivetrain is low and has a lot of space above it where they've slung the batteries to distribute weight. Honestly, given what the truck does, it doesn't actually need a huge amount of power. These monster trucks are more about noise and mayhem than speed or torque. They need enough power to turn the wheels reliably and that's about it. A mechanic friend here in town has a monster truck he's built from an old Ford and it only has 280hp in output from its in-line 6, but can climb wrecked cars and haystacks like a pro.

From the article it sounds like they kept the original drive-train mostly intact, but with electric vehicles that is really not necessary. They could have one motor directly driving each wheel. It might be more complicated for traction control systems, but I think it would be pretty awesome on a monster truck.

Most monster trucks use a locking differential because it is more durable. With motors on every wheel you could automatically send more power to the outside wheel when turning. An electric motor at each wheel would only need a reduction gear - because electric motors offer high torque over a wide range of rpms.
To do super tight donuts you could have the motors on one side go forward while the motors on the other side go in reverse simply by switching the direction of the current for 2 of the motors.

Other things like sending slightly more power the front at high speed to help the truck go straight would be easy to accomplish with separate electric motors.