11.5 second electric street car

[BigDan]

^ What if it didn't have to rely on stored energy like a battery but something like overhead power like a street car or bumper car or 1/2 mile extension cord. Just an idea for quickest ET

[THE EVIL TW1N]

Originally Posted by BigDan

More like quick and not so fast.

Very impressive and I would trade my Monte Carlo for one in a heartbeat but you would think it would of picked up some major mph from the mod's. Electrics would have my full respect if they could back up there super quick ET's with some high mph. This Datsun would get murdered on a highway roll race, I wish there was a way for it to kick ass on the top end as well.

good thing there aren't any tracks that do "highway roll race's", otherwise I could see it being an issue.

[DGthe3]

Originally Posted by LostInMoscow

Having spent 4 years of my life learning about electricity in engineering school, one of the tortures of graduation was learning everything that you never wanted to know about electric motors. Suffice it to say that you can wind an electric motor in a fashion to blow away just about any fossil fuel motor in existance today in the 1/4 mile. If you created a car with a battery, a power control system and a motor on each wheel, and the right combination of know how, you would be pushing 300 MPH in the 1/4. The car would be very very light in comparison to any other car since you would have no drivetrain other than cables and a battery only big enough to go 1/4 mile.

Is that a practical every day car? No way! But, don't underestimate electric motors for performance. You can do amazing things with them, as the industrial world already knows.

That would require several thousand kilowatts, for a span of a few seconds. That still works out to a few kilowatt hours of battery, which would would probably weigh 100-200 lbs, give or take. For an internal combustion drag car, the fuel cell only weighs a few pounds.

Then there is the electric motor itself. I don't know of any electric motors that pump out thousands of horsepower that are particularly light weight, though I'm sure some of that is because most such engines are industrial units and don't have a reason to be light. Never the less, the power to weight ratio for electric doesn't scale up all that well, at least in comparison to combustion engines. A 5000 hp internal combustion race engine doesn't really weigh that much more than a 500 hp engine. And since it has to haul around all those batteries, the electric motor would have to weigh substantially less than the ICE, and to do so it would have to have a power to weigh ratio on the order of 10 hp/lb. To my knowledge, they're not even halfway there yet.

Originally Posted by BigDan

^ What if it didn't have to rely on stored energy like a battery but something like overhead power like a street car or bumper car or 1/2 mile extension cord. Just an idea for quickest ET

That would help, but there is more of a problem with the motors than the battery for such a short race.

[ArkySS]

DG I know you have told us before but I know you have to be an engineer......since your from Canada I can possibly rule out NASA but not 100%

[DGthe3]

Originally Posted by ArkySS

DG I know you have told us before but I know you have to be an engineer......since your from Canada I can possibly rule out NASA but not 100%

Funny you should mention that, aerospace is the reason I wanted to get into engineering in the first place. Plenty of Canadians have worked for NASA. I won't be one of them, I just can't bring myself to leave Canada. But we do have the CSA ...

[8cd03gro]

Originally Posted by DGthe3

There can be an equal and opposite force that makes the net force equal to 0, thus preventing any acceleration. But that doesn't mean each force no longer exists. They simply exist in balance. It only ceases to exist theoretically after doing the vector addition. But both the applied force, and the reaction force are still there.

As a practical example, if you hold a weight out at arms length you feel gravity pulling it down. Consider that the applied force to your arm. To hold it still, you must exert a force to counter gravity, a reaction force. With what you seem to be proposing is that since the thing you're holding is not moving, it must therefore be weightless, which is absurd and untrue. Force exists without movement, and continues to exist despite equal opposition.

I understand why there is a torque based on simply analyzing the forces and the basic concept of torque, but in practice I can't think of a possible scenario where maximum torque output would not result in movement (unless an outside force is acting on the motor). I just don't understand how such a contradictory concept can exist. Most importantly, I know the relation between torque and angular accel, when referring to rotation, can be expressed as T=(mass moment intertia)(angular acceleration), so there is a direct relation between angular acceleration and total torque, so if angular acceleration is zero, so must be torque. . . Am I missing something here. . .? I can think of multiple examples of functions with domains (0,infinity), not [0,infinity) when torque is set to >0, that incorporate both torque and acceleration. I just don't understand how this is possible, unless it's situational and peak torque is only made at 0 rpm when there is an external load greater than the maximum torque output of the motor. . . which I guess makes sense.

I'm not trying to argue with you, just trying to understand why this is possible. I'm a physics student, so this kind of stuff drives me insane.

[DGthe3]

Originally Posted by 8cd03gro

I understand why there is a torque based on simply analyzing the forces and the basic concept of torque, but in practice I can't think of a possible scenario where maximum torque output would not result in movement (unless an outside force is acting on the motor). I just don't understand how such a contradictory concept can exist. Most importantly, I know the relation between torque and angular accel, when referring to rotation, can be expressed as T=(mass moment intertia)(angular acceleration), so there is a direct relation between angular acceleration and total torque, so if angular acceleration is zero, so must be torque. . . Am I missing something here. . .? I can think of multiple examples of functions with domains (0,infinity), not [0,infinity) when torque is set to >0, that incorporate both torque and acceleration. I just don't understand how this is possible, unless it's situational and peak torque is only made at 0 rpm when there is an external load greater than the maximum torque output of the motor. . . which I guess makes sense.

I'm not trying to argue with you, just trying to understand why this is possible. I'm a physics student, so this kind of stuff drives me insane.

You're going to make me find my Electro Mechanical Energy Conversions textbook, aren't you? Alright ... wait for an edit on this post ...

[Kyle2k]

Originally Posted by THE EVIL TW1N

good thing there aren't any tracks that do "highway roll race's", otherwise I could see it being an issue.

Texas mile.

Attempt at being witty = 0

Reality = 1

[THE EVIL TW1N]

Originally Posted by Kyle2k

Texas mile.

Attempt at being witty = 0

Reality = 1

Texas Mile is a track where you race just as in a 1/4 mi track. It says nothing about "roll races".

Kyle2k = -1

THE EVIL TW1N = 2

[Kyle2k]

Originally Posted by THE EVIL TW1N

Texas Mile is a track where you race just as in a 1/4 mi track. It says nothing about "roll races".

Kyle2k = -1

THE EVIL TW1N = 2

If you're going to declare points you better know what you're talking about.