Under the skin of the Zenos E10

By Christopher A. Sawyer
The Virtual Driver

(September 29, 2014) Unfortunately, the U.S. government doesn’t allow small automakers to certify their vehicles to a less restrictive set of regulations. In our ridiculously litigious nanny state, Big Brother feels that he cannot allow buyers to purchase a vehicle that doesn’t have the latest airbag technology, bumpers that can deflect small planets without damage, and that rely on driver-centered active safety instead of electronic babysitters.

As a result, Americans do not have the opportunity their European cousins do for driving road-legal track cars on the road.

One of the newest members in this class of car is the Zenos E10. It is the brainchild of Ansar Ali and Mark Edwards, both former leaders of Caterham Cars who arrived there via Lotus. Ali and Edwards consulted with Antony Doddworth, head of Doddworth Design and the former Principle Research Manager, Carbon Fiber at Bentley for help building their new car.

Not surprisingly, they wanted to use as much carbon fiber as they could afford, but — if continuous weave carbon fiber, like that used for the tub of an F1 car — was to be used, their grasp far exceeded their reach. A less expensive alternative had to be found, and one that didn’t rely entirely on the high-tech textile. In addition, Ali and Edwards were concerned about the operating cost of the car, they weren’t in business to shove cars out the door, rake in the money and forget their customers.

If anything, their time at Caterham — Ali used to call every new owner personally to see how their liked their Seven and if there were any problems or concerns with which he could help — taught them that a happy customer is a car company’
s greatest asset. And it didn’t hurt that a modular approach to design would not only make the car easier to service and repair, it would open the door to new products in which to move existing customers.

The rear subframe is made up of aluminum extrusions that are bonded and fastened together. It cradles a 2.0-liter Ford four and manual gearbox.

After talking with Multimatic CEO Larry Holt, Doddworth, and others, Edwards began to formulate a plan for the Zenos E10. “Mark took all of this information, combined it with a blog he was reading about restoring a Lotus Elan, and came up with a design that was cost-effective, serviceable, met the performance targets we had set out and, from a moral perspective, included items like side impact protection that the Small Series Type Approval rules didn’t demand,” says Ali.

According to Doddworth, Edwards soon thereafter came to him with a new design that may seem familiar to classic Lotus owners, but is bang up-to-date in terms of technology. “He asked if we could make the floor, side and bulkheads in my material, and use an aluminum spine to hold the engine and suspension. I told him it would be no problem.”

Doddworth’s material is recycled carbon fiber, essentially the stuff that would be swept off the floor and thrown out after a continuous weave product was molded. In fact, Doddworth had spent six years developing discontinuous carbon fiber plastic (DCFP) from scraps so small they “looked like barber shop floor sweepings.” Developed while he was as BMW, the original material took a modified chopper gun and shot the material onto a belt with a carrier placed between the upper and lower carbon fiber layers.

However, this material required the layers be knitted together like a fleece so the resin would be drawn into the material and not just sit on the surface. He had to find another way. Doddworth’s solution was simply brilliant: separate and bind the carbon fiber sheets together with McDonald’s drinking straws.

Made from inexpensive polycarbonate, the drinking straws were superglued together to form a field of I beam-like columns, and then were cut to a uniform 20 mm (0.79 in.) height. Resin is sprayed on either side of the sandwich, and it is placed on a heated aluminum die that forms this concoction into its final shape.

The cockpit is made up of discontinuous carbon fiber panels bonded to the main aluminum beam.

A 6.0-mm (0.24 in.) thick flange is created around the perimeter of the part. In addition to holding the panels together, it acts as a barrier to dirt and water intrusion, and as a bonding surface.

“The floorpan is one piece, and is bonded to the bottom of the extruded aluminum central beam,” says Ali. A thin layer of fiberglass mat separates the two materials, and prevents any galvanic corrosion on the backbone. “To this we attach the side panels and the front and rear bulkheads; five panels in all, and separate so that they can be replaced individually in case of an accident.” They also can be changed should Zenos wish to change the look or aerodynamics of the car without redesigning the complete structure. Even more interesting is the strength and cost of the DCFP construction.

Says Doddworth: “The completed material’s modulus in 97%-98% that of continuous carbon fiber, and it’s tensile strength is 60%-70%.” Unlike the wing of a Boeing 787, this “five-sided shoebox”, as Doddworth describes it needs to be stiff. It’s also relatively inexpensive. DCFP panels are about 1/10 the cost of continuous weave items, and have Class A surfaces. That is, they have a surface finish suitable for use on the exterior surface of the car.

The front coil-over dampers and steering rack are mounted to the top of the main beam, out of harm's way.

Hidden behind the DCFP side panels, and hidden from sight, are tubular steel impact bars that connect to the roll hoop. This provides protection to the passenger both on- and off track, and are not required by the low volume regulations. But it is the central beam that draws the most attention. This anodized, extruded aluminum piece is 2.1 meters (6.9 ft.) long, was optimized using Finite Element Analysis by Multimatic, and is the main source of the E10’s torsional rigidity. At the front, the coil-over damper units are mounted on the top of the beam where they are unlikely to be damaged in an accident. Long A-arms and pushrods connect the front hubs to the damper units, and act as sacrificial members. Even the steering rack is mounted atop the beam. “Everything in our design language is built around repairability,”says Ali. “When we say we want to create a brand that’s affordable, we don’t just mean purchase price. We mean ownership costs.”

The 200 horsepower naturally aspirated 2.0-liter Ford four-cylinder engine mated to either a five- or six-speed manual transmission (an turbocharged EcoBoost motor with 250 hp also will be offered)  sits in a U-shaped subframe built up from extrusions. “The two rear corners of the subframe are bonded and mechanically fixed to the main transverse beam,” says Ali, “but the leading edge of the subframe is mechanically fitted where it butts up to the bulkhead.” Thus, the rear subframe can come away from the bulkhead for repair. Though Zenos engineers would have preferred to use the same extrusion tool to build both the main beam and subframe members, the size difference was too great. Two tools are used to form all of the aluminum pieces for the E10.

Alcon brakes are used up front, but OEM discs are used in the back and include an integral handbrake unit. Buyers can order a windscreen package with wiper and motor, but they can’t order doors. The E10 is a step-in car.

“Doors can be the death knell
for any niche manufacturer,” according to Ali. “You can’t put down as an option, ‘Doors that work’ because the customer expects them to work properly first time, every time despite the fact that they are one of the toughest pieces on the vehicle to engineer. We want the E11 to be a door program only.” 

This addition will change the shape of the side panels, but they will be a simple substitution for the solid units of the E10. However, the E12 coupe, due to arrive in the 2017-2018 time period will add front and rear crush structures and airbags in order to bring Zenos up to full Type Approval compliance that should allow them to sell the car in the U.S. as a road car.

Much work remains to be done before that can happen. Development testing on the first two prototypes is underway, and the cars have been pavé tested at England’s Millbrook Proving Grounds, run for long stretc
hes at the Snetterton race track, and taken home at night and over the weekends by Zenos employees.

The prototypes have spent plenty of time on track at Snetterton.

The first group of buyers were invited to drive one of the two prototypes at Millbrook to assess the vehicle and provide feedback in August. Final development commenced this month, and production will commence in January. Zenos expects to reach a production rate of 200 cars/year by the second year of production at its 7,000 square foot facility in Wymondham, which is just down the road from Group Lotus headquarters in Hethel. Each will be built by 10 assembly people working in two groups of four, with two supervisors floating between the two assembly bays.

t the time of our conversation, Zenos had 68 firm deposits, and expected to have 100 in-hand by the end of September. U.S. customers will be able to buy track versions through Zenos Cars USA, with prices for rollers starting under $40,000. Ali and Edwards know that they have a long way to go, but understand the importance of every step forward they take.

“One big reason Mike and I left [Caterham] is that we didn’t want to work for a company that was just churning out thousands of cars. Putting aside brand and product, the dynamic with the end user is quite different. We prefer personal engagement and a real intimate relationship with the customer. We don’t want our relationship to them to be transactional.”

The Virtual Driver