In 1994, the GTP era ended and IMSA created the World Sports Car series. The team bought a Spice and put a Ferrari 348 engine in it. The cars were supposed to run with street based engines, but soon race engines became the norm. Dyson Racing participated in eight of the nine races, not running the 12 Hours of Sebring, with their best finish a third at Indianapolis.

Dyson Racing moved to the Ford powered Riley and Scott chassis in 1995 and began an eight year ran that netted them 36 wins including two wins at the 24 Hours of Daytona. In 1995, they did not finish off the podium for nine straight races from Road Atlanta to New Orleans, including five wins and a 1-2 finish at the last race of the season at New Orleans. James Weaver missed winning the championship by two points.

In 1996, Butch Leitzinger was third in the World Sports Car Championship. The team garnered seven podiums including a hat trick sweep of the last three events of the season.

In 1997, Dyson Racing took the top three positions in the championship: Butch Leitzinger followed by Elliott Forbes-Robinson and James Weaver. They started the year with a win at the 24 Hours of Daytona and were on every podium for the season with five wins out of eleven races.

The following year was no less successful. Butch Leitzinger won his second World Sports Car championship in a row, and was second in the Can Am Championship. (Run by the U.S. Road Racing Championship.) James Weaver was the Can Am champion and Elliott Forbes-Robinson and Dorsey Schroeder took third and fourth in Can Am.

Don Panoz bought Professional SportsCar Racing in 1999, and the American Le Mans Series was created, but the change of ownership did not slow up Dyson Racing. Elliott Forbes-Robinson won the ALMS Championship and he shared the Can Am Championship with Butch Leitzinger. The team added a second 24 Hours of Daytona win to their roster.

Rob Dyson: "In 1993, we bought a Spice and adapted the Ferrari 348 engine to it. I called Bob Akin again and said, "Bob, I've got a Ferrari engine I've got to trick up to run in this Spice." He replied, "Well, you have to see Ted Wenz." So we went to Wenz and he and Peter Marcovicci did a phenomenal job of rebuilding the engines, they were great engines. And the fans loved them. They had a great sound to them. It was loud and throaty and it wasn't like the Ferrari 333SP.

"Bob Riley had helped us make the Spice work a little better. He re-fabricated some uprights and some other pieces to make them work better. But he kept on saying, "I don't want to sell you parts, I want to sell you a car." So Pat Smith and I went out to Indianapolis late in the season and looked at what Bob had drawn up. As soon as he showed me what he had done, with the separate coils and shocks and the overall packaging, I said, "We will take two." You could literally change all the springs in the pits, in five minutes. And that is what got us into the Riley and Scott RS III."