Sunrise EV2 prototype as of 6/12/09

What's been done: steel chassis fabricated front and rear suspension installed brakes installed steering installed motor and coupler installed modify body for easier fabrication convert body to hatchback

What's yet to do: purchase and install batteries install controller and wiring build and install doors and rear hatch install glass design and build interior paint and trim documentation

Building a vehicle from scratch is a major project. There are endless tradeoffs between cost, performance, and time. Solectria's work gave us a tremendous head start; but many changes were still needed to make the Sunrise into a practical, affordable, high performance automobile.

These are "snapshots" of a work in progress. The design is still evolving. We run into problems, try different ideas, and decide on solutions. You might make different choices; but that is the beauty of a kit car -- you can make changes and build it your own way! And, let us know what you come up with. We might like your way better, and so can improve the design for other builders.

Donor Car

The entire suspension package comes from a 1989-1997 Ford Thunderbird or Mercury Cougar. It doesn't matter if the body is dented or rusty, or if the engine or transmission are bad, or if the interior is worn out. These cars can be purchased for a few hundred dollars. The parts you need are the front and rear subframes, steering column, doors, and all related parts.

Rear Subframe

This is what the rear subframe looks like. It is X-shaped with a large square space in the center for the differential. It attaches to the chassis with four bolts in rubber mounts in the corners. The suspension is fully independent, with upper and lower arms, half shafts, and coil springs on each side. The bottom of the photo is the front of the car. Depending on the year and trim option, it may have disk or drum brakes (with or without ABS); stamped steel, cast iron, or cast aluminum lower arms; and a Ford 7.5" or 8.8" differential.

The 8.8" differential is preferred, as it is stronger and a wider range of gears are available. The gears are changed to 5:1 to suit our particular motor and controller. The EV2 is rear engined, so the differential is rotated so the pinion points to the rear. To do this, a section of the front of the subframe was cut out, the differential rotated, and the piece welded back in to mount what used to be the back of the differential in front. Oil lines were added to convert the differential to dry sump lubrication.

Motor Mount

Brackets were fabricated from flat steel plate. They bolt onto the subframe, to provide mounts for the anti-sway bar and motor. The motor coupler is a standard industrial spider coupling. Minimal machining is needed.

The WarP 9" motor draws about 25 amps at 12 volts spinning the differential and wheels; a very promising number.

Alignment Jig

A temporary alignment jig was built from square steel tubing, to hold the front and rear subframes in position while the chassis was being constructed. It also allowed us to test fit the body, seats, steering wheel, etc. to be sure everything worked.

Front Subframe

This is the front subframe, temporarily mounted to our alignment jig. It attaches to the chassis with four bolts on each side. The suspension is fully independent, with upper and lower A-arms and coil springs. We have installed air struts in this photo. Note that the steering rack is very low, so the battery tunnel only needs to be elevated about 4" to pass over it.

The inside ends of the upper A-arms are mounted to fabricated sheet steel supports. These will eventually become part of the composite chassis.

Prototype Chassis

The main structural member in the EV2 is the central battery tunnel. It is a closed box beam, which provides tremendous stiffness and strength. This design originated with the McKee Engineering "Sundancer" EVs of the 1970's, and was further improved upon by high performance EVs including the Solectria Sunrise and GM EV1.

The prototype chassis was built from 16 gauge sheet steel. This was much easier to work with and modify than composites. It also allows "early adopters" who prefer working with steel to build their Sunrise the same way. We went through a lot of iterations in this process! At least four different rear chassis designs were built and discarded. It will be converted to composites once we have confirmed the basic design and dimensions.

The floor is also constructed from 16 gauge steel. The underside is completely flat, for minimal wind resistance. The weight is about 100 lbs more than the composite version; an acceptable compromise for our "test mule". The chassis is so stiff that it could probably be built with 20 gauge for additional weight savings.

The 4" space between the elevated front tunnel and the underside is used as a raceway for wiring, brake lines, and air ducts. Air flows in the front air intakes, under the battery tunnel, through the blower to the traction motor, and out the rear.

Body

Conventional fiberglass car bodies are not structural. They are very thick and heavy, but weak. Most are made with a "chopper gun" and polyester resin. Or, they are fiberglass "racing parts" that are only cosmetic; paper thin to be very light, but mechanically very low strength.

In contrast, the Sunrise body is structural; it adds considerably to the strength of the vehicle. The photo shows the opening cut for the rear hatch. You can see the lightweight foam core, varying between 1/4" and 2" thick, with a thin skin of fiberglass, carbon fiber, and kevlar cloth and epoxy resin. The different materials and thicknesses are used depending on the strength needed in each location. The resulting body only weighs about 200 lbs.

Here, the body is being lowered onto the test mule's chassis for another test fitting. Ultimately, this chassis and body will be used to make the molds for production parts. But they are also solid enough that we plan to install the batteries and controller so it can actually be driven.