The Porsche 718 Cayman GT4 RS Clubsport will conclude its chapter in IMSA and SRO competition with another championship, as RS1 delivered a fitting send-off before the Porsche 911 GT4 R takes over in 2027.
An opening-lap crash ended their race, but it couldn’t undo a championship-winning season. Luca Mars and Spencer Pumpelly clinched the 2026 Pirelli GT4 America Silver title at Indianapolis Motor Speedway by a single point.
Seven consecutive victories gave the No. 028 RS1 Porsche 718 Cayman GT4 RS Clubsport the cushion it needed to turn a dramatic finale into a championship farewell.
Mars sustained terminal left-front damage in an incident that also eliminated two other Silver contenders. With championship rivals Westin Workman and Tyler Gonzalez heading toward their second victory of the weekend, the RS1 pairing faced an anxious wait in pit lane.
RS1 was ultimately classified seventh in class but received sixth-place championship points because a one-off entry ahead was ineligible to score. Those points were enough to retain the championship advantage.
“It was a crazy day, a fantastic season,” Pumpelly said. “After having basically been taken out and our car destroyed on lap one, we thought the championship was lost.
“But sure enough, all the work we put in through the summer put us into a position where we could have a couple of bad races at the end.”
Saturday’s race had already complicated RS1’s title bid. Pumpelly was running third during the opening stint before a left-front puncture extended the mandatory pit stop, leaving Mars sixth in Silver and taking the championship fight into Sunday.
The finale’s early retirement meant the team’s dominant summer ultimately made the difference.
Porsche also secured two class runner-up finishes in the finale. Trenton Estep and Yves Baltas finished second in Silver aboard the No. 7 ACI Motorsports Porsche 718 Cayman GT4 RS Clubsport, while Matt Travis and Matheus Leist claimed second in Pro-Am in the No. 47 NOLASPORT Porsche.
Seven wins build the title-winning season.
RS1’s winning streak began at Circuit of the Americas and continued with double victories at Sebring, Road Atlanta and Road America.
Those seven consecutive Silver class wins built the points cushion that allowed Mars and Pumpelly to withstand their late-season setbacks.
“So proud of the team,” Pumpelly said. “Huge thanks to Justin and everyone at RS1, and Luca — just an amazing job this season. It was a joy to watch him drive.”
Mars credited the team’s determination throughout the campaign.
“Not the way we wanted to end the year, but we were able to bring home a championship,” Mars said. “Just a huge shout-out to Spencer and this whole team.
“Every time something happened, we just never gave up, and we kept working hard all year. Seven wins in a row really got us to this point where we could give up some races, as Spencer said.
“We’re super happy with this whole team, and Porsche and everyone who put all the hard work into this year.”
A championship send-off for the Cayman.
The result adds to RS1’s championship record with the Porsche 718 Cayman GT4 RS Clubsport, following GT4 America Silver titles in 2022 and 2024 and the IMSA Michelin Pilot Challenge GS championship won by Mars and Jan Heylen in 2025.
The 718 Cayman GT4 RS Clubsport has earned nine driver/class championships in North American competition, alongside more than 90 race/class victories across IMSA and SRO.
Together with the original 718 Cayman GT4 Clubsport, the two 718 versions have delivered 12 driver/class championships and approximately 150 race/class wins.
The earlier 981 Cayman GT4 Clubsport contributed at least 21 victories and two championships across IMSA and Pirelli World Challenge. One of those titles also belongs to RS1, which won the 2017 IMSA GS championship with Dillon Machavern and Dylan Murcott.
Exciting times ahead with the new 911 GT4 R.
For Volker Holzmeyer, President and CEO of Porsche Motorsport North America, RS1’s latest success provides a fitting milestone before the arrival of the
“We’ve come a long way — three different iterations of the Cayman since 2016,” Holzmeyer said. “To finish up with a championship in SRO and GT4 America is an awesome send-off.”
The Cayman’s racing career will continue within Porsche’s one-make championships. The 718 Cayman GT4 RS Clubsport remains eligible for Porsche Sprint Challenge North America and Porsche Endurance Challenge North America in 2027, while both the original 718 Cayman GT4 Clubsport and the RS Clubsport have a home in Porsche Sprint Trophy PCA and Porsche Sprint Trophy POC.
The new 911 GT4 R will carry Porsche’s GT4 program forward in IMSA and SRO competition, joining the 911 Challenge, 911 Cup and 911 GT3 R in a customer motorsport ladder increasingly built around the 911 platform.
“Now, with the new 911 Challenge, the new 911 GT4 R, then we have the 911 Cup car and 911 GT3 R — everything is 911-based,” Holzmeyer said.
“The first deliveries of the 911 GT4 R happened this week, and teams are about to start testing. We’re looking forward to seeing the car’s debut in Daytona next year.”
