Looking for help/advice for my mid-engine "locust" electric car build!

Do It Yourself (DIY)
1

First, the fun part… the car. It’s a custom built mid-engine vehicle with the general chassis design based off a “locust” custom/kit car. Mine has been lenthened and widened for purposes of comfort and design of the body. It’s mid engine as it uses the drivetrain of an MR2 but still awaits the electric motor and other components to be complete. Thats where I need a bit of direction.

Roughly I’m looking at about 1000 lbs. now but not official by any means; no est. yet for the fiberglass body, batteries, motor, controller, ect… It’s unlike the typical “locust” b/c it’s a fully enclosed 2-seater with a full body and resembles a street car more than a roadster. The majority of host parts having come from a late 80’s MR2. The batteries will be held on the front half of the vehicle and can be modified to fit as many batteries as needed.

I found this kit that looks good to me, but hoping to save a little by getting some stuff from second hand sources. The kit is a 72-144 Volt - Warp Medium Size Vehicle Kit from electricvehilesusa.com. It claims a 3000lb max weight which is more than enough for me. Using it at 144 volts it claims a range of 40-50 miles and a top speed of 90 mph. This is ideal for my application, and the kit comes in at $5700. My main questions are at the bottom…

Here are the specs of what it includes and it’s associated value. The kit itself goes into further detail on the webpage mentions above if theres a question as to the spec of any of the items mentions below;

1 of Battery Charger Zivan NG3 120V-288VDC 230VAC input ($1,350.00 value!)
1 of PakTrakr600EV Package ($149.95 value!)
1 of PakTrakr 6 Battery Remote ($68.95 value!)
12 of Battery Terminal Universal Heavy Duty 1 ga to 4/0 ga ($35.40 value!)
20 of Cable 2/0 Gauge - Black ($139.00 value!)
20 of Cable 2/0 Gauge - Red ($139.00 value!)
1 of Controller, Kelly 24-144 Volt 250amp ($998.00 value!)
1 of Contactor, SW-200CW W/ Blowouts 12 Volt Coil ($229.95 value!)
1 of Contactor Albright Reversing SW202-84, 12 VDC Coils With Blowouts ($349.50 value!)
5 of Lug Straight 2/0 GA 5/16" Hole ($14.95 value!)
10 of Lug Straight 2/0 GA 3/8" Hole ($29.90 value!)
1 of Motor WarP 9" Up to 192 Volts Dbl 1.125" CE Shaft ($1,800.00 value!)
1 of Switch Power Cutoff - Heavy Duty 5000 Amp ($89.95 value!)
1 of Throttle PB-6 0-5K Lever ($89.95 value!)

What substitutes could be made with these parts? Such as, what alternative motors (both size and specs) could be used if I’m going to do as much as possible on a budget using ebay and other second hand sources to get parts? Please be semi-specific as I’m still pretty new to EV’s but will be starting to get parts soon!

What could be excluded if buying these parts sperately, or as I expect, is everything on the list a must have?

Does the kit mentioned above really have the potential to provide the specs it implies? What could be added or changed to increase range and still maintain the speed?

I know the batteries are alot of the equation so, what and how many batteries would be ideal for this setup? As mentions above, I would like to keep the speed this package claims but wouldn’t be against an increased distance if possible, haha. For now I expect to stick with sealed lead batteries but open to other suggestions if it warrants the additon cost.

Besides the batteries and adaptor plate, what else is needed to make a vehicle using this kit come to life?

2

Most of that kit is fine but the motor controller sucks. You’ll want to be able to push more than 250 Amps if you need to accelerate fast.

As far as the range and top speed those are both closely related. You will NOT get 40-50 miles at 90 mph. So much of this depends on batteries. 40-50 miles is probably at 45-50 mph. You might get only 10-20 miles at 90 :slight_smile:

There are some good books out there on conversions that are great for getting up to speed on all the math and physics to consider on any conversion. The weight of the vehicle will affect your range during acceleration or inclines and your coefficient of drag will affect range at speeds usually at and above 45 mph. The rolling resistence of your tires has a huge impact on range at all speeds but is the largest factor until speeds of again about 45 mph where wind then becomes are larger resistence. You might also want to think about Lithium batteries if you can afford the up front cost.

That kit is definately a large majority of what you’ll need. As long as the pak tracker gives all your basic voltages, amps, etc your good except for all the little things you find you need along the way. Smaller gauge wiring for 12v systems, wiring connectors, material for building the battery mounts and possibly boxes (a must if they are in the car). You’ll also need a way to mount the motor the car, typically reusing the original motor mounts.

Again I’d pick up some books and find as many conversion pages and read, read, read. Until you understand exactly why you need every part on the list, I wouldn’t order anything yet. Your design might change the items you really need. For example you don’t need that reversing contactor unless you plan on trying to run the motor in both directions (if you’re using a tranny you don’t).

Just scratching the surface, but hope it helps some.