Audi A4 quattro

Having turned rallying on its head with four-wheel drive, Ingolstadt brought the technology to the track. For a season the A4 quattro reigned – and then came 1997…
Words: Keith Howard. Illustration: Audi Tradition

According to your viewpoint, the 1990s were either the golden era of the British Touring Car Championship or, with big names and budgets increasingly involved, the beginning of the end for a series whose cottage- industry status had once been a key element of its appeal.

If any car epitomised the arrival of big clout and big bucks, it was the Audi A4 quattro. It is remembered as the four-wheel-drive car that put the cat among the 2WD pigeons and romped off with the 1996 driver and constructor championships. But it was more than that. It was the product of a massive engineering and development effort at Audi’s Ingolstadt HQ that spread its tentacles throughout touring car racing. In 1996 the same car won seven championships worldwide, as far afield as Australia and South Africa.

Nevertheless it was beaten into second place in the BTCC in 1997 by the Renault Laguna built by Williams Touring Car Engineering. How the A4 shook up touring car racing, and how Williams beat it, is recalled here by Roger King, then Frank Biela’s race engineer at Audi Sport UK, and Tim Newton, who was technical operations manager at WTCE.

Engineering

RK: “Joining Audi Sport UK was an eye-opener. The factory had run a development programme which ran to the beginning of the ’96 season. Every part had been validated, so we knew exactly when we had to change it. This meant that reliability was assured. Apart from the accident when Biela hit oil, we had a 100 per cent finishing record.”

TN: “At Williams we tried to apply F1 standards and thinking to touring cars. It wasn’t about being fancy or clever but just trying to get consistency. Touring cars used to be hand-built and therefore all different, and unreliable as a result. The Audi was the ultimate car in this respect: it was designed, drawn, built in a large factory. Everything had a part number, it was a proper car. We didn’t have a factory, we had mechanics who made many different parts. But I would get them to make, say, six brake pipes at a time, so they were all the same.”

Weight penalty

RK: “When we started in ’96, TOCA gave us a 65kg penalty. But we made the mistake of being successful from the outset and it was increased to 95kg. After that there was no sandbagging, we were flat out – so the penalty was well chosen. We put the ballast, mostly bolted-down lead sheet, in the passenger footwell. That gave us the corner weights we wanted and placed the extra mass as low as possible.”

TN: “I think two-wheel drive and four-wheel drive should always be in different classes. No equivalency formula really works. It was the right decision to ban 4WD from 1998, but I don’t think it should ever have come in. The front suspension strut they ran on the A4 was also a fairly broad interpretation of the rules, because it wasn’t the same as the road car’s. I think there was a bit too much of a big company with lots of money having things go through.”

Differentials

RK: “The A4’s standard diff arrangement was viscous couplings front, centre and rear. We typically ran a 60:40 torque split front to rear, but we tuned it from race to race. On a circuit like Thruxton with fast, open corners you’d want as much torque to the back as possible, whereas on tighter circuits like Knockhill you could put a bit more to the front. We ran a spool [locked diff] at the rear sometimes, where we needed really good traction and there were no sharp-entry corners where it would give you understeer.”

Handling

RK: “The car had to be set up to understeer. Oversteer would kill our lap times, but there were various ways of curing it. We could take a bite off the front downforce, change the rear differential, lower the ride height or change the rear toe angle. With the FWD cars the handling balance would change radically as the front tyres started to deteriorate and the rears came up to temperature, giving more and more understeer. We didn’t have that problem. We quickly warmed all four tyres, and the wear was almost even all round.”

TN: “Michelin made a big contribution to our success in ’97. They always gave us great tyres. But it was difficult to get heat into the rears. Because we didn’t have tyre heaters, the car would go out for one qualifying lap with the front tyres on the back and the backs on the front. When it came in, the front wheels would go on the back and the rear wheels would be crossed from side to side and put on the front. That was the most effective way of getting the rears warm.”

Drivers
RK: “Having Frank Biela was a huge advantage. He’d been through all the development and knew the car inside-out. If you looked at the throttle traces, he was Mr Precision. It was all square lines: either full on the throttle or full off. The quattro was incredible like that: because of its traction you could use the throttle as a switch. John Bintcliffe struggled because he didn’t know how to make the car work. He’d come from a FWD car and was lost.”

TN: “Alain Menu was a single-seater-style driver – very smooth, very composed. Will Hoy was very good too, but the required driving technique had changed. Alain’s style suited the car better because it had aerodynamics, it had downforce. You had to drive it like a racing car, not like a stock car.”