[john kirk]

Hi Everyone (first post)

I have been thinking about building a EV for a long time now.
As a kid I was mad on Kit Cars (never got one)
As an adult I have restored old cars and fixed engines at a piston ring level.

Sure, it would be great to build that insanely fast petrol track day car... but where's the challenge in that ?

I want to run some initial numbers past the forum:-

My aim is to build a 2 seater mid engined EV using a composite monocoque chassis with front and rear subframes. (I have a donor car in mind) Shell and running gear will be well under a metric ton.

70+ mph
70+ mile range

Performance ... spirited but not looking for a racer

Budget for all electrics, £6000

First question:-

Direct Drive through a Diff -Or- Maybe 2 speed gearbox ?

As I understand it direct drive through a diff is the better performance option but is there any range to be gained by using a gearbox ? and the associated loss of efficiency by introducing gears. ?

Lastly... any off the shelf packages (or suggested recipes) to achieve this out there for the above budget ???

thanks !

[Tomdb]

read duncan's thread.

Its lightweight and relatively cheap.

Because of the DC motor, scrounged from a forklift.

For range id calculate with about 0,14-0,2 kwh/km depending on your driving style.

http://www.diyelectriccar.com/forums...ice-44370.html

It all just depends on what you mean by spirited.

And 6000 pounds is gonna be quite hard, building a gas guzzling version is almost that price for a okay one.

[john kirk]

Thanks !....

£6000 was just for electrics... ie motor and batteries..

So... for a

70 mile range and a top speed of 70 mph what sort of money am I looking at for the electrics ?

Spirited im looking at mid range small family car performance.

[Tomdb]

for 6000 pounds you probally cannot get the battery pack.

70 miles is about 120km give or take.

120km x 0,2 kwh/km = 24kwh

if u can get cells at 1,1$ per Ah then you would need 8250$ worth of Ah.

Without shipping, bms or even mounting hardware.

[john kirk]

Thanks for the advice.I really am at square 1 as you can tell!

Could you suggest what I would need to meet the targets I've set in one final realistic financial total for all my electrics

Many thanks.

[Tomdb]

i would look around on here or on evalbum.com there are quite a few builds with detailed cost and specs.

[TEV]

Originally Posted by Tomdb

for 6000 pounds you probally cannot get the battery pack.

70 miles is about 120km give or take.

120km x 0,2 kwh/km = 24kwh

And you need a 30KWh pack in order to get a 24KWh at 80% DOD (20% SOC)

[john kirk]

So... Im looking for a 30KWH Lithium battery pack.

thanks.....

What motor next to pair with the pack ?

Am I right in thinking , this is the amount of battery and sort of size motor im looking at ?

[Tomdb]

here is the evalbum listing compleet specs.

130km top 150km range with a 27kwh pack (22 useable) 50kw peak motor.

here is an thessis about the conversion with alot of useful information. http://www.tue.nl/uploads/media/EVS25-K4U0UV0P.pdf