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REVR Kit

Article is light on details but from looking at the photos it uses hub mounted motors. Hub mounted motors are a big controversy in the EV conversion community because....well they don't really work. A hub mounted motor needs to make all the torque to move the car at the hub, no gearing in between. Think about your gas engine and the transmission and then the final drive ratios all working together to turn the 200 ft-lbs or so into 1000+ ft-lbs at the tires themselves. Well good luck getting that with a hub mounted electric motor. There are a bunch of articles like this and lots of promises, but no hub mounted motors that you can actually buy (outside of motorcycles/scooters). It's just such a huge engineering challenge. Not only that but the hub is subject to the most abuse of the entire vehicle. The hubs are unsprung so they experience the most g-forces from bumps and potholes, they get splashed by puddles and mud, etc.

Also $5000 is extremely optimistic. Right now you can't get a battery for $5000 that will power a vehicle 62 miles. That number is just plain wishful thinking.
 
J1000 said:
Article is light on details but from looking at the photos it uses hub mounted motors. Hub mounted motors are a big controversy in the EV conversion community because....well they don't really work. A hub mounted motor needs to make all the torque to move the car at the hub, no gearing in between. Think about your gas engine and the transmission and then the final drive ratios all working together to turn the 200 ft-lbs or so into 1000+ ft-lbs at the tires themselves. Well good luck getting that with a hub mounted electric motor. There are a bunch of articles like this and lots of promises, but no hub mounted motors that you can actually buy (outside of motorcycles/scooters). It's just such a huge engineering challenge. Not only that but the hub is subject to the most abuse of the entire vehicle. The hubs are unsprung so they experience the most g-forces from bumps and potholes, they get splashed by puddles and mud, etc.

Also $5000 is extremely optimistic. Right now you can't get a battery for $5000 that will power a vehicle 62 miles. That number is just plain wishful thinking.
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History is replete with examples of engineering that shouldn't have been possible. While I'm not disagreeing with you, how about we see where it goes. After all it doesn't cost us anything to find out if they become successful or not, only time will tell.
 
That’s some helpful insight, thanks.

With all that you laid out it seems like we may never see this particular kit “hit the shelves.”
 
where does the giant battery go?
how do the controls work?
if you are running off the battery, how does power steering, brakes, and everything else that takes input power frp, the engine work?
does it regen?
how many miles before it catches on fire?
 
J1000 said:
Article is light on details but from looking at the photos it uses hub mounted motors. Hub mounted motors are a big controversy in the EV conversion community because....well they don't really work. A hub mounted motor needs to make all the torque to move the car at the hub, no gearing in between. Think about your gas engine and the transmission and then the final drive ratios all working together to turn the 200 ft-lbs or so into 1000+ ft-lbs at the tires themselves. Well good luck getting that with a hub mounted electric motor. There are a bunch of articles like this and lots of promises, but no hub mounted motors that you can actually buy (outside of motorcycles/scooters). It's just such a huge engineering challenge. Not only that but the hub is subject to the most abuse of the entire vehicle. The hubs are unsprung so they experience the most g-forces from bumps and potholes, they get splashed by puddles and mud, etc.

Also $5000 is extremely optimistic. Right now you can't get a battery for $5000 that will power a vehicle 62 miles. That number is just plain wishful thinking.
Click to expand...
My thoughts as well. Looking at all the golf cart stuff, I saw Silverwolf has a hub motor kit to turn golf carts into on-demand 4wd. The hub motors don't look like they would hold up long.
 
Some back of the envelope math on the battery. 62 miles. Lets be nice and use 200 W*hr per mile. Current Lithium ion battery packs are about .11 kW*hr/lb and 450 W*hr/L.

So you need 12,400 W*Hr or 12.4 kW*hr. Which works out to about 112 lb and over 27 L.
 
What about a 9 inch drop in 3rd member with an electric motor mounted to the pinion? Don't need a fancy housing just one of the cheaper stamped housings they have available. You get the gear reduction you need along with something with off the shelf axle shafts and bearings. Add some sort of attachment for your driveshaft to hook up to with some sort of disconnect for the hybrid.

Another option is similar to an ecobox where you add an electric motor between the transmission and the transfer case. Or you can put in a 4 wheel drive transmission in a 2 wheel drive application. I like this idea better seems way simpler. The additional low end torque would be interesting in a wheeler too.
 
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