Quote:
Originally Posted by Clev
Agreed, being able to run through the transmission gives you some mechanical advantage, but there is some extra driveline loss involved with running through a transfer case, not to mention extra weight and complexity. If you're driving the front diff directly, you won't have great acceleration, but generally you don't need that in stop-and-go anyway.
Something else you might consider is an e-wheel, like this guy did on his Insight:
Mikes Insight - MIMA Honda Insight Modified Integrated Motor Assist
Basically, it mounted underneath where the muffler was, and was geared to a top speed of 45-65 (depending on voltage), with the wheel retracting above that. You have a ton of open space under the bed and could do something similar, geared to top out at, say, 40-45 mph at 72V, and then have it retract above that speed. Again, not great acceleration, but probably sufficient for stop-and-go (and puttering around town at 25-35 mph) and a lot lighter than transplanting in a 4WD setup. By having it retract (he uses an air cylinder), you don't have the drag of the transfer case and hubs, and you wouldn't need a transmission, at least on flat ground. The Etek motor also has regen, so you could recover some of that energy while stopping and going. |
Thanks for the info Clev. I actually have considered the retractable motor solution, and still am. Also a chain drive to the drive shaft, and some other stuff. I am new to all this and still need to understand how the motors function with respect to free spinning, rpm capacities, drive through capability, etc.
Originally interested in regen, but seems 10% recoup doesn't justify cost and complexity.
Is there a source to calculate acceleration given weight and power? This will be my primary design criteria. I need to be able to have reasonable accell in S&G traffic, prob something like 0 - 35mph in maybe 15 secs, for 15 - 20 miles. I need to time it. Everything else will follow.