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Cosworth powered Group4 Lotus sunbeam |
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Although I'm a Ford fan myself
I have always had a soft spot for the old Lotus Sunbeams. My brother and
fellow Motorsport enthusiast, had owned LTT 646W for 14 years and was one
if not the best Lotus Sunbeam in existence. This car had won numerous
concourse days in both class specific and general classic shows. The time
had come when although concourse is lovely to see, the longing for a FAST
Lotus track car was too great. The first task was preparing the shell. The
car was stripped to a bare shell, and the front and rear arches modified
to take Gp4 arches. The next
addition was a set of Bilstein 2 ¼" coil over units coupled with AP
four pot calipers and 260mm alloy bell grooved/vented discs up front,
whilst the rear uses Sierra cosworth calipers and mk3 escort front discs. These discs
were limited in size due to the wheel size choice. 10X13" for the
rear and 8X13" for the front. The next step was to fit the
multipoint weld in cage. This was installed to MSN regulations with the
necessary foot plates welded to the shell. The cage was fabricated to pass
through the front bulkhead picking up from the front struts, whilst the
rear sections pick up off the rear suspension pivot points to give an
extremely stiff shell. Interior has been limited to carbon buckets, and
an alloy dash, along with Perspex windows, all
in an attempt to reduce weight. In the engine bay, a new bulk
head was fabricating allowing the engine to be moved rearward by
4 inches. The engine required a special sump to be fabricated to
clear the cross member and allowed the engine to be lowered as much as
possible in the engine bay. Up front the tie bars and TCA's are fully adjustable rose jointed affairs to allow Inside the car a fly-off hydraulic hand brake is used, a plumbed in fire extinguisher system is present and the dashboard houses only necessary gauges and switches, the majority of the car having been stripped/removed/cut out to remove excess weight. Up front the new cosworth power unit has been developed for maximum torque and response. The specification is extensive but maintains a Garrett T34 turbo in order to give a wide on boost power band of of 3200rpm to the 7600rpm limit. We have mapped the cars on greys and uses one of our triple cosworth intercoolers. This car has been competing for two years now in numerous speed and hill climb championships around the country, with occasional visits to santa pod and various race circuits for "fun" track days. Our current best Qtr time is 12.2@120mph at Santpod.
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