Background
The car was homologated by the FIA into both Group N and Group A categories on the 1st December 1989. The Golf Rallye G60 incorporated a supercharged version of the 1800cc 8-valve engine, reduced to 1764cc in order to bring it within the three litre class limit due to the forced induction multiplication factor.
To comply with the regulations modifications to the engine were limited, although it did benefit from blueprinting which balances the engine components to each other and so reduces vibration, modified camshaft profiles to provide higher lift and longer duration and finally porting and polishing of the cylinder head to remove the burrs left by the manufacturing process and so smooth the flow of gasses.
The greatest improvement in horsepower came from modifying the supercharger, which involved changing the drive gears and balancing the internals. These changes coupled with the modifications mentioned above allowed the engine and ultimately the supercharger to spin much faster thereby increasing the power developed from the standard road car’s 160BHP to an eventual 290BHP.
Further ingenuity was felt in the 4wd gearbox, which was based on that from the Passat but incorporated six speeds and an FF viscous differential. The FF differential combined the best of both worlds the outright speed of 2wd, but the grip of 4wd as the car ran mostly in front wheel drive with drive being diverted equally to all four wheels only when loss of drive was detected at the front.
Technical
Engine : four-cylinder, 1.76ltr, in-line, transversely mounted in the front of the car, twin overhead camshafts, two valves per cylinder, 290 bhpInduction : Fuel Injected, Supercharged
