Electric 5th Wheel

[trikkonceptz]

Hey guys, here is another crazy idea I wanted to run past you all. Since my car is 99% hwy driven I was thinking about creating a 5th wheel unit that was powered by and electric motor. However I would only engage it once I was up to hwy speed to maintain 65mph. I know its possible with gearing and such but what would happen to an electric motor going from 0mph and being dropped to maintain 65mph? I can work out the logistics for batteries and such later, but this is the first question I had ..

Thanks

[Andyman]

It would be smart to power up the motor and have the wheel match the road speed before lowering the wheel to the pavement. Otherwise the tire would get a lot of wear as it skids before it speeds up to 65 MPH. You will probably need at least 20 HP to go 65 MPH. That is about 15 KW.

A regular gasoline engine is pretty efficient when going fast. When you go slow you can save energy by turning off the engine and using electric power.

Somebody else has this idea also. He calls it the E-wheel. You can read about it at <http://www.99mpg.com>.

[trikkonceptz]

Similar to that obviously, but better. I will have to use a trailer wheel, which handle handle the load and speed and in my case running it @ 65mph would be most efficient for me since I run 60 miles one way to work each day on the highway. So 60miles @ 800 rpm is much better than 60mph @ 2200 rpm.

But i guess the answer is that I have to get the tire up to speed before it hits the floor? The wear on the trailer wheel is insignificant really, they cost next to nothing, but I am more oncerned about damaging an electric motor.

[dremd]

might look in to the AWD Vibe bits, could drive the existing 2 wheels, just another crazy idea to go with yours

[trikkonceptz]

Great IDEA !!! I forgot these things come AWD ...

[dremd]

That's what I'm here for :-)

I want to do an r32 back half in the Golf bad. Couple it with a electric clutch and a small (6.4") motor and 7 12 volt cells .

[mattW]

Your ICE is already pretty efficient at maintaining a set cruise rpm (much more than stop and go). Electric motors at highway speeds burn up amps pretty quick so you are going to need a lot of batteries. I honestly don't see you having much of a gain from this system... I would go with electric at low speeds and kick the ICE in for highway. Or if you swapped out your motor for a smaller one you could cruise with higher throttle openings and just use the electric for the occasional times you need to pass someone or go up a hill. If you want to improve mpg you've gotta match the strengths of the different motors to their tasks.