- Free-revving V8 engine sounds great
- Traction from quattro system contributes to capable dynamics
- Supportive front seats
- High standard of interior fit and finish
- When pushed, nose-heavy body produces understeer
- Suspension lacks compliance
- Instruments difficult to read
- Cramped rear seat
Overview
Released in April 2005, the Audi B6 S4 Cabriolet was a two-door, four-seat convertible with a soft-top roof. Manufactured in Ingolstadt, Germany, the Audi S4 Cabriolet was powered by a 4.2-litre V8 petrol engine that was mated to a six-speed automatic transmission and drove all four wheels via Audi’s quattro four-wheel drive system.
4.2 V8 engine
The Audi S4 Cabriolet’s 4.2-litre BBK V8 petrol engine had a cast aluminium alloy block, die-forged steel crankshaft that operated on five main bearings, a cast aluminium alloy cylinder head, double overhead camshafts per cylinder bank (chain-driven), five valves per cylinder actuated by roller rocker cam followers, variable intake camshaft timing, a variable intake manifold, a compression ratio of 11.0:1 and maximum engine speed of 7200 rpm.
Although based on the AQH/AVP/AYS/BCS engines in the Audi D2 S8 , the length of the BBK engine was reduced by 52 mm to 464 mm so that it could fit in the engine bay of the Audi B6 S4. This reduction in length was achieved by transferring the chain drive to the clutch side of the engine and using chain-driven camshafts.
The Audi S4 Cabriolet could accelerate from rest to 100 km/h in 5.9 seconds and had an electronically limited top speed of 250 km/h.
| Engine | Trans. | Drive | Peak power | Peak torque |
|---|---|---|---|---|
| 4.2-litre BBK petrol V8 | 6sp auto | quattro | 253 kW at 7000 rpm | 410 Nm at 3500 rpm |
Dimensions and suspension
Like the Audi B6 A4 Cabriolet on which it was based, the S4 Cabriolet was 4573 mm long, 1777 mm wide, 1391 mm tall and had a 2654 mm long wheelbase. The S4 Cabriolet had four-link front suspension and self-tracking trapezoidal link rear suspension.
quattro and electronic differential locks
The Audi B6 S4’s quattro four-wheel drive system utilised a Torsen T2 centre differential. In normal conditions, the system provided a 50:50 front:rear torque split but up to two-thirds of the engine’s torque could be directed to either axle if traction was lost. The system also included open front and rear differentials with electronic differential locks which could brake spinning wheels to enable cross-axle torque transfers at speeds of up to 80 km/h.
Safety equipment
Standard safety equipment for the Audi S4 Cabriolet included dual front airbags, front side airbags, ABS, electronic brake force distribution, brake assist, electronic stability control, traction control, an automatically deploying roll bar and seatbelt pretensioners and load limiters for all seats.
Brakes
The Audi S4 Cabriolet had radially ventilated front and rear disc brakes; the 345 mm (diameter) by 30 mm (width) front discs and 300 mm by 22 mm rear discs were both fitted with single-piston sliding calipers.
Features
Standard features for the Audi B6 S4 Cabriolet included 18-inch Avus III alloy wheels with 235/40 R18 Contintental tyres, a ten speaker Bose sound system with a ten-disc CD changer, dual zone climate control air conditioning, combination Alcantara and Nappa leather seats, power adjustable front seats, driver’s seat and mirror memory settings, cruise control, xenon headlights, front and rear fog lights, automatic headlights, a leather-wrapped steering wheel with gearshift paddles, remote central locking, power windows and heated mirrors, tilt and telescopic steering wheel adjustment, a wind deflector, an alarm and immobiliser.
The S4 Cabriolet’s power-operated, triple-layer fabric roof had a heated rear window and could be opened or closed within 30 seconds.
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