Hayden Cobra Origins: Chapter 4
Updated: Apr 11, 2019
In this chapter we explore the chassis design changes to suit larger and taller drivers, the decision to use an advanced resin for the body and other changes that have made the COBRA such a success with the discerning buyer.
The multi-tube chassis which Les developed for his new Cobra was enthusiastically received by the larger and taller drivers, who appreciated the much lower seating position which this new chassis offered. They no longer had to sit on top of a 100mm chassis member but could now fit properly into the car and instead of looking directly at the top of the windscreen frame, they now could look through the glass. With the multi-tube chassis it was easy to drop the seats by 100mm, and this has made a huge difference to the comfort of larger people.
Another advantage of this lower seating position was that Les could now rake the windscreen back more than the standard angle of rake, and this improved the aesthetics of the car, as many people feel that the standard Cobra windscreen is mounted in too upright a position and that it would look much better if slanted back a bit.
Another criticism from owners of early cars was that after some time there was a tendency for slight ripples to appear along the top surface of the front fenders. Les suspected that this might be caused by heat distortion of the body, as it was in the area directly opposite the engine and exhaust headers, which radiate off a lot of heat when the car is stopped after reaching normal operating temperature.He contacted his resin supplier who denied this possibility, saying that their General Purpose polyester resin could handle temperatures as high as 80 degrees Celsius. However, when Les spoke to the supplier of resins to the manufacturers of the Nissan Sani vehicles, he was told that their experience was that their body panels could reach temperatures of over 100 degrees C just from sun exposure when painted in dark colors. Les was advised to change to a more expensive vinyl-ester resin for his Cobra bodies, as this has a far greater heat distortion tolerance. He took this advice, and had no further problems with ripples on the front fenders.
His badge supplier offered to supply the round Cobra badges fitted to the front and rear of the car with a new type which was covered in clear resin. These looked good and were tried for a while, but dropped after it was noticed that the clear resin had a tendency to discolor in time. Les therefore reverted to the original badge design of slightly domed brass pressings, chrome plated and enameled.
The side louvers were improved by a re-design after two cars were shipped to the UK for SVA safety inspection, and all sharp edges had to be replaced with rounded ones. Although not a requirement in South Africa, Les decided to use these new louvers on his local cars anyway.
The next problem to be addressed was a further increase in interior space, as Les believes that we ignore larger customers at our peril. In a car as small as the Cobra, this is no easy task, as the designer has to cram so many big components, including a hefty V8 Engine and transmission, large brakes, large differential and huge wheels and tyres into a car with a wheelbase shorter than a VW Citi-Golf.
How this was accomplished will be related in the following chapter.....