1983 Sebring 12 Hour – David and Goliath

The 1983 Sebring 12 Hour was an epic event. Back then the race was run on the ‘old circuit’ which was over 5.2 miles in length, bumpy, in disrepair, and it was a real battle to even finish a 12- hour event there, being very hard on both driver and equipment. Since about 1971, it had been the domain of Porsche as they had repeatedly won there with cars from the 917 to the Carrera RSR and the 935. However, 1983 would be no different, although this time the highly favoured 935 would not be the winner. But we are getting ahead of ourselves in the story.

The story actually begins at the end of the 1982 IMSA season. Wayne Baker had approached the Garretson Racing Team about running in the IMSA GTO class for the 1983 season. He was looking for the team to build and prepare a Porsche 934. The goal was to win the IMSA GTO championship. Wayne had run in IMSA from time to time in the GTU classification with his Porsche 914/4 with some success. The Porsche 934 was legal for the IMSA GTO class in 1983 as the rules were quite open for GTO in IMSA at this time. But these were not 1976 FIA Porsche 934 cars, because despite these cars in effect looking like a 934, that was where the similarity ended. Basically, the car had to run a single turbo engine, and have 934-type body work but with smaller wheels and tyres than the 935. Jerry Woods’ and Wayne Baker’s idea was to build an IMSA 934 out of Bob Garretson’s 1982 935 car which was the now famous chassis 009 0030. So, at the end of 1982 Bob sold the 935 to Wayne and the Garretson crew went to work on the conversion. Don Araki in San Diego did a lot of work to the chassis, basically cutting off the whole rear and making a ‘Moby Dick (factory 935-78) type’ tube structure behind the firewall, really adding to the stiffness of the car. Jerry Woods built a 3.2-liter engine, with the mandatory single turbo. He used a KKK K36 turbo, which was about as large as they came, because a bigger turbo meant more air, which in turn meant more power. Realising the turbo lag would be a huge issue for drivability, he devised a twin waste gate system for the single turbo, which really improved drivability quite a bit. The rest of the crew built up all new 935 suspension, drive shafts and systems, preparing the car for the upcoming 24 hours of Daytona. We did not use the standard Porsche wiring harnesses because the car was totally rewired with aircraft quality wiring and connectors. Since one of our crew members, Ron Trethan, worked at Raychem, we had access to all the latest high tech wire and connectors as used by the US Air Force, so the whole car was rewired with that.