Concept A

[robchalmers]

I've been toying with the idea for years, but I've decided that I now want to try and make my own EV. With the help of you guys, my friends in Bentley's Green power project and a few friends at Castle Creations. These are the targets I'm setting

1.carry 4 people+30kg load
2.Range = 100 miles+
3.Cruise speed 65mph+
4. has to acheive 80% ofpoint2 including extented times @ point3 whilst carrying 2 people

At the moment I haven't decided on layout, or construction but it would have to be simple design - most like to go open source once the bugs are sorted. The project is going to be a long one but My main aim is the car to be simple, modular to aid retrofitting upgrades and most importantly use existing technology to act as recycling.

[Daox]

Those are some fairly high goals you have there. You're going to need a heck of a battery pack to support 100+ miles. I'd probably start looking at small pickup trucks so it can carry the weight.

[MazdaMatt]

Standard issue question number one: How much you gonna spend on it?
You can do it if you want to pay 20k. I'd love to see a high-dollar build-up on this site as most of the others are el-cheapo (which is a good thing, too!)

[robchalmers]

clean sheet design

aiming to keep it light to loads down, hub motors to get rid of driveline losses....... even a 5th wheel regen braking - lots of randomness - lots of ideas that will probably not work. I think it was Edison who was asked how many failures did he have at making a working lightbulb. he answered - none. asked if this was incredibly lucky to get it right first time , he said 'no, I found thousands of successful way of making a non-working bulb and one way of making a working one' there alone is his genius (parapharsing hugely there!!)

[robchalmers]

@Matt, Haven't completely thought out Budget yet...... need to basic calcs first on what power/weight etc is needed

[MazdaMatt]

Spend some time on DIY Electric Car Forums Site Home EV Photo Album: Our Electric Cars on the Web and Domain Name For Sale - contact: info@nucom.com and you'll find lots of examples of people who have done exactly what you're looking at and they often talk about they issues and costs.

Are you looking to convert a car/truck, or design/build your own vehicle?

[robchalmers]

design my own obviously i may pillage certain components from other cars

[roflwaffle]

How big are the people? If it was up to me I'd grab ~600-800lbs (30kWh) of LFPs, a pickup truck frame (~4500lb gross vehicle weight, but w/ no cab/bed/driveline it should weight in south of 1000lbs), and slap a compact car body on there, somewhere around 1500lb w/o the driveline/suspension. If you're thrifty and handy the body should be under $1000, but the pack would be ~$7,500-10,000, plus the motor/controller/etc, so maybe ~$10K-13K.

Having sliding battery racks connected to the frame would be neat imo and good for weight distribution, and instead of the rear axle, an old 4spd FWD transmission in the front or the back would save a couple hundred pounds compared to the stock axle/rwd trans/etc. All told I think you can get the curb weight near ~3500lbs, which should get you about 100 miles of range at 65+mph, provided you went with a LRR tire set and the alignment was as straight as possible.

[robchalmers]

Thinking about the tray idea and LRR tyres. I might get the drive train etc working in a small hatch to prove everythin out before making the final bespoke monocoque. final concept I want with cells but without passenger to be around 2000-2500 lbs with ultr simple interior and super low Cd

[The Atomic Ass]

Originally Posted by robchalmers

Thinking about the tray idea and LRR tyres. I might get the drive train etc working in a small hatch to prove everythin out before making the final bespoke monocoque. final concept I want with cells but without passenger to be around 2000-2500 lbs with ultr simple interior and super low Cd

Your thinking is quite similar to mine, although I'm shooting to seat 6 and have an 80% DOD range in the 250 mile range.