Audi rallye Quattro A1
The A1 at the 1983 Portugal.

The rallye Quattro A1 was really just an evolution of the Gr.4 Quattro, but homologated to fit the new Group B class change coming from FIA. It had it’s first rallye the 1983 Rally Monte Carlo, and the last at the Safari rally the same year. The price for such a machine in 1983 was set to 285 000 DEM.

Engine: inline 5, cast-iron block, alu-head, 10V, special steel-conrods.
Capacity: 2145 cc by bore 79,51 mm x 86,4 mm stroke
Compression-ratio: 6.3:1
Power: 340 hp / 6000 rpms
Torque: 414 Nm / 3650 rpms

Early versions fitted with K27 turbos, while some used K26 at 0.8~1.9 BAR. Most significant was probably the use of the motorsport Pierburg mechanical injection. Standard inlet- (38.2 mm) and outlet valves (33.3 mm) was changed for 41.1 and 35.2 mm ones. Dry sump and a Matter & Obermoser fuel tank was positioned in the trunk, and the engine had a heat-treated, forged crankshaft.

Generally, the rallye Quattro A1 introduced the lightweight materials to the rally Quattros, alike body panels, suspension struts and the engine block – actually named A1 from exactly this aluminium usage.

Visually, most noticeable is the wider fenders with the air inlets in front of the rear arch and the change for Michelin tires. Matter had 3 versions of rollcages, in aluminium or steel.

Many shared dimensions (except for the track width) as for the Group 4 car, but weight is now between 1130~1140 kg. The car was succeeded by the further developed Quattro A2, and seems somewhat short lived, but many cars has been modulary upgraded with the newer parts and body panels.