1954 Jaguar D-Type
Design requirements for the D-Type said it should be
lower and shorter that its predecessor. This would help the car achieve a
higher top speed and increased cornering capability. Most of the form for the
car came from mathematical computation with the help of Malcom Sayer. Initial
tests on the unpainted prototype car, chassis XKC401, revealed a top speed of
178 mph, almost 30 mph faster than the Type-C!
At the heart of the D-Type was an innovative chassis
structure. It used stressed-skin engineering, incorporating the framework with
riveted aluminum body panels to form a single rigid structure. Such design made
the D-Type one of the first cars to use monocoque construction. As on the
C-Type, both the front and rear panels of the car remained unstressed and
easily removable for repairs.
The 1954 D-Type used a magnesium alloy for it’s
body, framework and suspension. While this did keep weight down, it made
production expensive and repairs even more expensive. By 1955 these materials
were replaced by simple aluminum and steel counterparts.
The XK-based engine powering the D-Type played a
large role in helping achieve a high top speed. It was both shorter, thanks to
dry-sump lubrication, and more powerful than the previous engines. The
combination of a revised block, larger valves and triple Weber carburetors
helped the engine achieve 245 bhp.
Dunlop disc brakes were employed to all four wheels.
Jaguar worked exclusively with Dunlop during the fifties to adapt aircraft disc
brakes to road cars. In 1953 the first use of disc brakes was witnessed on the
C-Type works cars. It was this potent feature that helped the C-Type achieve
victory at the 1953 Lemans.
Suspension of the D-Type type used double wishbones
up front with a rigid axle in the rear. This was the familiar setup found on
all production Jaguars during the period.
