Z Wheelz, LLC . . . San Antonio, TX, USA . . . firstname.lastname@example.org
The ZW2-C (Z Wheelz 2-seat Custom) is a prototype "American Hotrod" electric kit car built in 2007. The third iteration is underway as the "EZ-EV" open-source electric vehicle.
ZW2-C CAD drawing rear view with roll cage.
The main frame is a simple steel "battery box with wheels". It is modular and adaptable to many different battery sizes and types. This CAD picture shows the frame filled with 24 deep-cycle sealed lead-acid batteries.
The rear subframe can fit a variety of electric motors and drives, and it bolts to the main (battery) frame. The double-sided swingarm is completely adjustable and bolts to the rear subframe.
The belt-driven rear wheel assembly.
A belt-pulley housing waqs designed for use with the MES-DEA electric motor.
A single 75 amp-hour battery installed for reference.
The MES-DEA 200-250 AC induction electric motor.
This is the frame with the front end attached and no batteries installed. It will have a windshield and front fairing with a locking storage area, and a roll-cage with side protection bars.
An in-dash PC is being used to program and display the controller status, setup the charger, and display and record PLC data including the State Of Charge (SOC) of the main battery pack, rpm and temperatures. The PC also has a GPS with roadmaps and an AM/FM/mp3/DVD stereo system.
The auxiliary battery and DC-DC converter are fed into a solenoid and through the main fuse for the 12 VDC system. The components are mounted on wood and will be fiberglassed together to form the electronics enclosure behind the seats.
The center console contains a shifter for park/reverse/drive/economy mode, a parking brake, and two control knobs for the regeneration level and the current limit.
The instruments and controls are laid out in wood to determine the final layout before wiring and fiberglass work. A speedometer is located in the center, with a key switch and main battery pack connect (big green button) located below the amp-hour meter which displays voltage, current and amp hours remaining.
The batteries are dropped into the front and rear openings and then slid in to the front crossmember. They are wired in series using short jumpers. A circuit breaker and fuse are also in series to a large connector and up to the drive electronics that are contained within a rear fiberglass enclosure.
The full battery pack is installed: 24 group 31 gel cells. This is 1700 pounds of sealed lead-acid batteries for a max range goal of 80 to 100 miles. Daily driving range would be 40 to 50 miles depending on driving style and desired battery life. About 1000 daily cycles can be expected. The frame and drive system as shown is 1000 lbs. Expected empty weight is 3400 lbs with windshield, fairings and roll cage.
64.5ah * 288v = 18576 kwh @ 1hr rate
97.6ah * 288v = 28108.8 kwh @ 20hr rate
Here's a clip from the local news from 5/16/08
This is not the final roll cage but it will do to get it on the road and start some real testing. A new tube bender will be able to do the sweeping bends that are shown at the top of the page in the CAD picture. Luggage pods may be added behind the roll bars.
The stock Honda windshield is an off-the-shelf safety-glass windshield and together with the large steel frame they will provide better protection and better aerodynamics. The nose shape will not follow the windshield frame down tubes, it will be raised and rounded. The windshield will use the stock Honda wiper system. The windshield frame will be connected to the front fairing (trunk) and front fenders next. An option may be a smaller fairing with small acrylic bubbles and only the roll bars and side bars for a lower, more open feeling.
The frame will be raised 1.5" using stiffer springs, and then another 3.5" by mounting the main frame on top of the lower front crossmember. The CG will still be low and it will be much more practical. The belt and pulley on the final drive will be increased to 37mm to handle the power and weight.
A Honda Fit windshield was chosen for max length and minimum width. The rough foam frame will be fiberglassed and then rubber-mounted to the steel tube frame.
The headlights are mounted and the VIN number has been assigned by TXDOT. The dual-hydraulic rear caliper bracket is being fabricated for rear and parking brakes. The vehicle will be rough but legal for motorcycle inspection and registration. The front fairing will be completed while getting some real-world miles as-is.
August 2008 - It is now insured, inspected and registered. The maiden voyage from the shop to the house went well. The cooling system and rear brakes are done and the lights and horn make it legal. Lots of testing to go but it'll be good to get some real miles on it. Odometer was at 100 miles for inspection. It rides nice but everyone keeps staring at me!
The trip home was 17 miles and it used 5120 WH total. There was 5 miles flat at 50 mph, 7 miles small hills at 40 mph, and 5 miles 30-40 mph flat with stop and go. This is 300 whpm average. Regen has not been enabled yet, it will be wired next week and tested on the same route.
A trip downtown to the Live Green Fest was 13 miles and 15 miles return at 30 - 40 mph, some hills and normal stop and go traffic. Data shows 272 and 286 whpm average usage.
First highway drive - 18 miles, normal accelerating, hilly, no regen, 60 mph average, four stops - 7550 Wh used (420 wh/mi). 60 mph up steep hill with good acceleration remaining, pulling 188 amps during momentary acceleration to 65 mph and still pulling. Average current 100 amps, 80 amps downhill and 120 amps uphill. Starting voltage 315 VDC, lowest voltage up hill at 60 mph and accelerating - 240 VDC. Speed and range tests will continue in small steps as time permits. Planning on moving headlights out, up and back to allow open-wheel fairing and reducing angle of windshield to flow better into front end.
Main focus will be finishing Porsche 911 kit and Sprinter van hybrid EMIS installation.
Averaged constant energy usage readings, level ground;
30 mph = 250 whpm
40 mph = 300 whpm
50 mph = 350 whpm
new video, thanks to Eric and Joey in Austin!
ZW2-C frame rear view (without roll cage).