View Single Post
Old 11-17-2008, 01:21 AM   #767 (permalink)
Moderate your Moderation.
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
MetroMPG - are you considering doing any of the aero mods to this EV? I bet you could substantially extend your range by doing so... Even just the simple things... you don't need a front vent area at all, considering that ambient air cools forklift engines, therefore the whole front end of the car could be sealed...

We all know quite well that the rear of a Metro/Swift benefits from Kammback designs greatly..

Next, what about further weight reduction? Have you ever considered reversing the motor's polarity as a means of braking? If you could do that, it would eliminate the need for the braking system altogether, thus increasing efficiency and range further. (That is indeed alot of weight.) It's also one less pedal.

End-ride pallet jacks use this method to stop. You simply pull the controller in the opposite direction, it reverses the polarity in the motor, causing it to attempt to spin in the opposite direction. You would have the approximate potential torque of the motor stopping you, hence you would probably stop faster, although with a potentiometer-type controller, you could also vary your braking easily, as you can on the above-noted jacks. You would also save money by not buying brakes/pads/rotors/calipers/drums/fluid/lines/etc/yougetthepointbynow.

If not interested in motor-braking, maybe you considered adding a reclamation system to the current braking system? I'm not entirely sure how these work, other than converting inertia to electrical energy through heat absorption (I think).

Adding LED lights in place of incandescent for the turn signals, etc. would also be a help when it comes to both saving money for maintenance costs, as well as electrical usage. Plus, they can be had relatively cheaply, especially if you're into old electronics... computers have them. Plus, they'll at least last for the useful life of the car, meaning they'll never need replaced.

Another note on weight reduction, removing the factory wiring harness and stripping out the unused wires, as well as replacing the factory bushings with urethane (if it's available) will help with weight, and the bushings will help with handling, meaning you can safely corner at a higher speed, increasing efficiency. Weight loss can also be had by removing noise reduction material in the chassis, to the tune of ~30-50 lbs in some cars.

Obviously, if it's legal, plexi weighs less than glass... and the parts removed from the car could be sold to recoup some of the costs of conversions and additions/subtractions/modifications.

Given consideration to any of these ideas, the cheapest would obviously be the aero-mods, since you've already done some of them once, and could take information and results from that car, and duplicate them on this one.

The second cheapest, although not necessarily range increasing, would be the second idea... the reason I say it's not necessarily going to increase range, is that it takes battery power to slow you down/stop you. While you may not actually need to brake that much, since you can still slow yourself using gearing, it still might toll slightly more on the packs during normal use.
"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

Last edited by Christ; 11-17-2008 at 01:27 AM.. Reason: added information
  Reply With Quote