[ncc74656m]

Originally Posted by Blue Bomber Man

ncc74656m,

I have actually spent the last 4 weeks researching exactly what you are talking about and have been able to learn much. A few weeks ago I posted a thread about building a car from scratch, that it would be all electric, and have a 100 mile range.

Im still working on the conceptual stages of the project as I have yet to obtain my copy of solidworks or a new computer to aid in the actual design.

But here is some useful information:

This is a link to a Phd's Research on vehicle loads and specs.
PAMVEC: Parametric Modelling of Road Vehicle Energy Consumption

His spread sheet allows you to enter in vehicle weight, rolling resistance, CdA (value for combined Coefficient of drag and frontal Area), range, performance, and other variables.

Entered in numbers from my current car and it basically nailed my epa rating for gas mileage. It also provides data for various drivetrains such as: gas, diesel, electric, parallel hybrid and series hybrid.

My current specs/goals are:
<1200 Lbs
120 mile range
0-60 14 seconds
onboard energy usage of 250 watts for vehicle functions (not propulsion)
Cd ~ .13 Frontal area 20 sq feet
RRC of .065

For the electric version it recommends about an 11kw hour battery back
Current price for the lithium polymer ion version is around 10k

Fortunately I will not be building this for around 1-2 years, so I HOPE the prices come down on those.

Estimated MPGe (equivalent comparing kw hour prices to gasoline) is around 380 mpg.

The gas version of the same car would be around 100 mpg, which seems reasonable, diesel would be higher.


His spreadsheet takes into account passengers weight, vehicle driving cycles, different drivetrain efficiencies, and even regenerative breaking.

My current guestimate price for batteries, motors (found these SWEET wheel hub motors with everything built in, not sure if they will sell directly though), BMS (battery management system) is around 20-25k

The nice thing about an electric car is that it would be extremely low maintenance. Only real maintenance is battery replacement (old batteries should certainly be sellable).

Also, I am completely sold that all electric is the future for the industry, especially as battery or capacitor tech evolves. The only exception would be with onboard generators, similair to what chevy and others are doing.

Did I mention this is the kinda stuff I come here for?

Like your above mentioned plans, my car is a pipedream, in that there is no way I can yet afford to build it, BUT I can start to plan and know what it is I'm looking for.

I'd like to be able to keep my weight that low, but is that possible with the batteries in question?

I'd also like to know more about the hub based motors. I've mostly looked at the potential for the single motor like the Warp series. I've read and heard about the hub based motors, seeing videos of the power of the torque and efficiency, so I'm wondering which would be better, the hub or single motors?

Also, would you just put them on two wheels (front or rear) or all four corners? I should imagine that all four corners would be an impressive way to keep traction with the high torque in winter situations, and also improve reaction speeds.

I'm planning on using a '91-94 Tercel for this project in all likelihood, and if not, probably a similar period Civic hatch. What would you think of these as bases for the systems. I know the Civics are popular conversions, and the Tercel I have experience working on, so...?

Also, here's another idea/question: Without a front mounted single motor (using hubs), is there any reason you could/should not split the battery packs and divide them to attempt to get a close to 50/50 weight dist? Obviously I'm assuming that you find a way to weatherproof the engine bay and seal it off.