I'm surprised there's been no thread on this yet, first overall win with an EV:
http://www.thetruthaboutcars.com/2015/07/silent-but-violent-watch-rhys-millens-record-run-up-pikes-peak/
I'm surprised there's been no thread on this yet, first overall win with an EV:
http://www.thetruthaboutcars.com/2015/07/silent-but-violent-watch-rhys-millens-record-run-up-pikes-peak/
Pretty badass to win, set a new record and be pissed off that you could've been 30 seconds faster if the car didn't lose power to the rear wheels on the way up the hill.
What's with the siren? Did they rig it to the brake light to keep him off the brakes, or is it to let pedestrians know that there is a silent rocket headed their way?
Tyler H wrote: What's with the siren? ...is it to let pedestrians know that there is a silent rocket headed their way?
Yes
Very, very cool.
An interesting thought has crossed my mind, though. An electric motor is going to make the same power at sea level as it is at 14k feet, right? Obviously it will be heatsoaked by the time you get there, but if you were to do a cold dyno pull at the base of the hill and one at the summit, they would be incredibly similar, correct?
I wonder how much of a loss in power the internal combustion engines are seeing over the 4k foot elevation change. I know that forced induction greatly helps with the thinner air, but I'm positive there's still a sizable loss. Then again, the internal combustion engines with forced induction are also going to heatsoak.
It would be interesting to see dyno charts of Sebastien Loeb's car from last year vs. Rhys Millen's car from this year at the various elevations, both cold and heatsoaked.
Pikes Peak is the perfect venue for ev racers. Short enough that battery life isn't an issue and the IC cars are handicapped by the elevation change. I know that at 5000', we lose about 15-17% engine power relative to sea level. It would be a similar problem at the Peak as well. Forced induction cars see a drop in efficiency and response time, so they suffer as well.
On a turbo car, higher altitude basically pushes the turbo 'up' on its compressor map, which means it has to have higher shaft rpm to make the same boost (takes longer to get there), has a little more pumping loss on the exhaust side to get it there, and is in a less adiabatically efficient part of its map. It CAN be a dramatic loss if you take a car with a nearly maxed out turbo at sea level and drive it up to 14000 feet, but it can also be a pretty minor issue on a car that was set up with those conditions in mind.
Keith Tanner wrote: Pikes Peak is the perfect venue for ev racers. Short enough that battery life isn't an issue and the IC cars are handicapped by the elevation change. I know that at 5000', we lose about 15-17% engine power relative to sea level. It would be a similar problem at the Peak as well. Forced induction cars see a drop in efficiency and response time, so they suffer as well.
The stuff I was reading said 30% power loss from start line to finish line.
That gives the EVs a huge, HUGE advantage.
one disadvantage to EVs in racing.. batteries weigh the same if they are full of charge or empty. Where an ICE powered race car can get significantly lighter during a race or fuel can be added so that it has -just- enough to finish to keep it lighter
mad_machine wrote: one disadvantage to EVs in racing.. batteries weigh the same if they are full of charge or empty. Where an ICE powered race car can get significantly lighter during a race or fuel can be added so that it has -just- enough to finish to keep it lighter
I'm too lazy to do the math, but in a race this short, I can't imagine even the monster cars losing enough fuel weight to overcome the drop in power.
Cooling for EV's can be just as big a problem as it is for IC engine'd cars. The same issue with power and altitude affects the cooling side too. An EV car I was associated with that went up the hill a few years ago had some cooling issues as it had been developed closer to sea level...
I would think that another advantage that an EV has is the torque coming off those slow corners. EV's have very high torque at very low rpm.
z31maniac wrote: Also, if this continues, I hope EVs get their own class.
IIRC, they're already in their own class. But the overall win is the overall win
The Weight of the gas that is burned is not insignificant. I would think it would run between 60-90 LB (1-2 MPG) But the power loss from the altitude is going to be much more than the advantage of 60-90 LB of weight loss over the run.
bmw88rider wrote: The Weight of the gas that is burned is not insignificant. I would think it would run between 60-90 LB (1-2 MPG) But the power loss from the altitude is going to be much more than the advantage of 60-90 LB of weight loss over the run.
Yes, that's exactly what I said.
bmw88rider wrote: The Weight of the gas that is burned is not insignificant. I would think it would run between 60-90 LB (1-2 MPG) But the power loss from the altitude is going to be much more than the advantage of 60-90 LB of weight loss over the run.
I agree, the amount of fuel consumed is not enough to make a large impact on performance.
The fastest bike up the mountain in 2013 was electric. At that time I asked "Does this mark a turning-point in motorsports?"
Now the fastest cars up the mountain are electric. The top cars at Le Mans are hybrids. The F1 grid is all hybrid. Formula E has become a high-profile international auto racing series. The flagship cars at Ferrari, Porsche and Mclaren carry electric motors--in fact, Ferrari plans that its future V12 models will all be hybrids.
I never imagined this coming in my lifetime.
There's a big difference between hybrid and pure electric - I think the latter is only going to work for very specific events until rapid recharging is figured out. The Formula E solution of changing cars is pretty dumb. But I do love the Le Mans hybrids in particular. I'd love to see someone work out a range extender solution for that, so the drive is 100% electric and an on-board generator (turbine?) provide the energy.
what we need is for either the energy density of batteries to increase quite a lot, or for batteries to be developed that can handle having absurd amounts of electricity dumped into them in a very short period of time without getting damaged. Back when I messed with RC cars a lot, the general rule of thumb for charge rates was 1C, with C being the capacity of the battery in amp-hours (4300 milliamp-hour battery charging at 4.3 amps, for instance), and the current crop of LiPo batteries have safe maximum discharge rates around 70-100C. Ideally if we could safely get the charge rate as high as the discharge rate (without lowering the discharge rate) or even higher than it, that would work. Or, find something other than batteries to store (or create) the electricity necessary to run the cars.
Also, this has me quite intrigued about the idea of electric cars for autocross... in a car at/around A-mod minimum weight (FSAE/Formula Student electric cars have been light enough to kick in the teeth of the conventional gasoline FSAE/FS cars for quite a while now IIRC, so ~900lbs w/ driver is definitely possible if you have enough creativity, skill, and money to throw at the car) you wouldn't need a massive motor to get enough power/torque to spin the tires at basically any speed you wished, and thus you wouldn't need hundreds and hundreds of pounds of batteries to get decent runtime/range out of it... a single motor with a diff would be leaps and bounds easier to set up and control than having individual motors for each rear wheel (mounted inboard, driving the wheel via a simple gear reduction and a CV shaft for less unsprung weight and more simplicity and for not needing to buy specialized hub-center motors), but the latter would let you do some wonderful things with torque vectoring if you had wheelspeed sensors on all 4 wheels, a yaw sensor at the CG and lateral accelerometers at either end of the car...and had the requisite degree from MIT to figure out how to use those inputs to program the motor controller so that it would be exceptionally hard to get into a situation where the motor controller acts based upon said sensor inputs and actually makes the problem worse
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