2003 Pilbeam MP91

Images courtesy and copyright Bob Chapman @ Autosport Image
Text copyright Michael J. Fuller
The 2003 Pilbeam MP91 is a development of the MP84.  The Pilbeam chassis was originally conceived for the FIA SR2 category which mandated an aluminum honeycomb monocoque and ran at a minimum weight of 740 kilograms.  While the MP91 claims substantial aero gains over the -84 (40% more downforce for 4% less drag), it is still dogged by its aluminum monocoque in attempting to pare down to the ALMS class minimum of 675 kgs.  While a valiant effort for a small chassis constructor, the MP91 is still not a purpose built -675 car and suffers performance-wise when compared to its MG and DBA4-03 class competitors. 
Click on each image below...
2003 Pilbeam MP91 Specifications
Layout: Mid-engine, rear-wheel drive
Monocoque: Aluminum honeycomb monocoque with steel roll hoops
Engine: Willman 6 (JPX/IEX) 6 cylinder, 120 cylinder angle, 4 valves/cylinder, breathing through one 41.7 mm restrictor
Displacement: 3397 cc
Gearbox: Hewland NMT 6-speed sequential
Suspension: (f&r), Unequal length wishbones, pushrod actuated, inboard rocker arms
Dampers: Koni 2812 2-way adjustable and Eibach springs
Brakes: (f&r), AP aluminum 4-piston calipers, carbon metallic pads, with AP ventilated cast iron discs
Wheels: O.Z. cast magnesium alloy
Tires: Dunlop
Length: 4455 mm
Width: 1900 mm
Wheelbase: 2550 mm
Front Track: 1500 mm
Rear Track: 1600 mm
Weight: 690 kgs.
Tank capacity: 60 liters
ęCopyright 2003, Michael J. Fuller