Formula One, Lammers starts his World Sportscar Championship career in 1983 by joining top Porsche privateer Richard Lloyd Racing, taking several podium finishes with Thierry Boutsen, Keke Rosberg and Jonathan Palmer, while finishing sixth on his Le Mans debut. In 1984, he is paired with Palmer, and the Canon-liveried 956 takes victory over the works cars at Brands Hatch. The two add podiums at Monza, the Nürburgring, Sandown Park and Imola, and retire from Le Mans in a winning position. A mid-season switch sees Lammers snapped up by Tom Walkinshaw at TWR Jaguar, and on his debut for the team at a very hot Shah Alam in Malaysia he brings home the Jag in second place. Meanwhile, he makes his IMSA GTP debut racing a March-Buick at Miami with Roberto Guerrero. In the 1986 Daytona 24 Hours, driving the BF Goodrich Porsche 962, he is heading for victory when his brakes fail, leading to a sizeable crash that he is lucky to escape from. Later in the season, when his promising IndyCar adventure collapses with the disappointing Eagle, Walkinshaw is quick to lure Lammers back to TWR. The Dutchman is immediately competitive with second at Spa and third at Jerez, before racing for Nissan at Watkins Glen in IMSA GTP. In 1987, Lammers joins TWR Jaguar – now sponsored by Silk Cut – as a proper works driver, and is teamed with Grand Prix veteran John Watson. They win at Jarama, Monza and Fuji and take podiums at Silverstone, Brands Hatch and Spa. At Le Mans, third driver Win Percy crashes their car out of the race. Team orders mean that they finish second in the championship. 1988 would become Lammers’ most successful season in Group C racing. Now paired with ex-Lotus Formula One driver Johnny Dumfries, the two finish second at Spa and third at Brno, before being joined by Andy Wallace at the Le Mans 24 Hours. Lammers drives for 13 hours to be the anchor in a popular win for TWR Jaguar, the first for the marque since 1957. For this, he is congratulated by Queen Elizabeth II and rewarded with the title of Honorary Member of the BRDC. In IMSA, Lammers is part of the crew that wins the Daytona 24 Hours, after he is moved over from his retired car to join Martin Brundle, Raul Boesel and John Nielsen in the lead Jaguar entry, winning