With sights set on the 1981 World Rally Championship, ex-Porsche engineer Ferdinand Piech (Ferdinand Porsche was his great-uncle) concocted a supercar from mainly Audi 80 components
, designated 'Quattro'.
Starting as the A1 prototype in 1977, the square-cut two-door was developed as a four-wheel-drive high performance machine, and the production version utilised the engine from the 1980-introduced 200 5T four-door saloon.
The engine was a turbocharged (KKK) fuel-injected five-cylinder in-line 2144 cc unit that used an air-to-air heat-exchanger which redensified the ingoing air at the intake by a temperature reduction of 50 deg. C. (122 deg. F.).
The temperature was in fact brought down from 130 deg. C. (266 F.) to 80 deg. C. (176 F.). The result was that, with a boost pressure of 0.85 bar (12.32 psi) at 3500 rpm, the engine gained 30 bhp (22.37 kW), developing a maximum output of 200 bhp DIN (142.54 kW). Maximum torque (210 Ib ft/281.61 Nm) was developed at 3500 rpm.
Another original feature was a microprocessor developed by Hitachi of Japan which controlled ignition advance and retard in conjunction with the injection over a spectrum of 265 sensitive periods in the operating cycle (an inlet temperature-sensitive device automatically retarded the ignition to avoid detonation, in addition to anti-knock equipment).
The main novelty of the chunky German coupe, though, was the 'total drive' concept, developed in the main from components in production for VW's cross-country 'litis'. Like the Range-Rover, all four wheels were permanently engaged in drive, the five-speed gearbox (from the Audi 200, with geared-up fifth) being mounted behind the five-cylinder engine, vertically over the front suspension.
A clever feature was the use of a hollow secondary shaft which drove the locking cage of the central differential, which in turn drove:
The front differential via the hollow shaft, a layout which miniimises gearbox size.
Directly, via a conventional propeller-shaft, the rear axle diffferential.
To increase the already impressive traction in treacherous conditions, there were two locking devices controlled from the dashboard: a sliding, grooved ring which locked front and rear drive units 100 per cent locking on the rear differential only. The system weighed only 15.42 Ib (7 kg) more than that of the Audi 80
Quattro's suspension was virtually identical to the Audi 80
at the front, but at the rear the coil spring/damper system (located by a Pan hard rod) positioned the wheels with a slight toe-in attitude. In spite of its chunky lines the Quattro 4WD had a respectable CX figure of 0.40.
When shod with 205/60 VR 15 tires it would top 135 mph (220 km/h); but it was in the acceleration department that the car was most impressive, having a 0-62 mph (0-100 km/h) figure of 7.1 seconds on dry roads, falling to a perhaps even more impressive 7.5 seconds on slippery going.
The latter graphically illustrates the efficiency of the transmission. A 16-valve version with a maximum power output of around 320 bhp (238.62 kW) was implemented for Group 4 competition.