The American Le Mans Series and Grand-Am had yet to be conceived the last time sports car teams completed the “36 Hours of Florida” under the same championship banner.

IMSA’s World Sports Car prototypes and three classes of GT cars started off the 1997 season with the Rolex 24 at Daytona followed by the Twelve Hours of Sebring, and with sports car racing set for a major divide in philosophies, 17 years would pass before the Daytona-to-Sebring swing would happen again.

Coming off of their GT Le Mans class victory at the Rolex 24, Porsche Motorsport North America director of operations Owen Hayes chronicled the unique challenges of starting off the season with the two biggest endurance races held back-to-back, and what’s required to prepare their 911 RSRs for another grueling run in Florida.

“Sebring is obviously a long-distance race which means that a car has to be completely overhauled and meticulously prepared before going into the event,” said Hayes (LEFT). “This is especially true after coming off another endurance event, the Rolex 24 at Daytona. The two Porsche 911 RSRs are stripped down to a bare chassis, not a component remaining on the cars, which will then be inspected in minute detail and built up again. Of course, we would do that regardless of what the next event is because the cars take so much abuse over a 24-hour race cycle, but racing back-to-back endurance events demands the most focused attention to detail that one can imagine.

“Endurance racing is a challenge. The stresses the cars are placed undergo beyond any lab condition we could devise and that is the very point. Porsche has always sought this kind of punishment to simultaneously prove and improve our road car product. The current generation Porsche 911 on the street owes not only its speed and handling but also its impressive reliability and longevity to the history of endurance races at Daytona, Sebring and Le Mans.”

Reassembling the cars is tasked to CORE autosport, the South Carolina-based team responsible for running the GTLM program on Porsche’s behalf. Thanks to the heavy punishment the cars receive on the aged Sebring track surface, the Nos. 911 and 912 RSRs begin the event with a long list of fresh components installed throughout the chassis.

“For the Sebring race event, the cars will need new suspension, new coolers, a new engine and a new gearbox,” Hayes explained. “This is all done at the shop before we bring the car back to Florida. It is the equivalent of building a brand-new car around a race-proven chassis. The basic philosophy is to fit the car with as much new equipment as possible to ensure reliability over this arduous race. As Sebring is a very bumpy circuit, it is a very hard endurance test for any race car. Just to give an idea of how bumpy the track surface in Sebring is, the amount of input energy that the suspension experiences will be at a level of approximately four-times that of a ‘normal European FIA circuit.

“This means that although the race is ‘only’ 12 hours long, the suspension will experience four-times the mechanical loading compared to other ‘normal’ circuits. In effect, from a suspension mechanical loading point of view, you are attempting to complete 48 hours of mechanical loading on the car within a 12-hour race duration! You will get that kind of load nowhere else in any other sanctioned race event anywhere in the world.

“The wheel loadings due to the bumpy Sebring circuit do not, however, just stop at the suspension. The loadings and vibrations are of course transferred further through the gearbox, the engine, the chassis and, finally, into the driver. This is what makes Sebring such a unique survival challenge, not only for all of the components in the car, but also for the driver.”

Moving from the Rolex 24 (BELOW) to Sebring (ABOVE) also involves wholesale setup changes, as Hayes details.

“Changing the cars from Daytona to Sebring configuration also requires fundamental changes in setup philosophy,” he added. “Daytona is a high-speed circuit where the cars are aerodynamically trimmed out to run at high speed on the oval portion of the track. However, Daytona is relatively smooth. Sebring is a bumpy but fast circuit that comprises many characteristics. As an example, you have low-speed corners such as Turn 7, ‘The Hairpin,’ which is taken at approximately 45 miles per hour. You have mid-speed turns such as Turn 15 that nearly double that speed to 80mph. You also have high-speed Turn 1 that can be taken at speeds of 110mph in a GT Le Mans class car like the Porsche 911 RSR. So, the cars need to be set up with this in mind.

“The differences make for more compromises on the suspension side. We are looking for a setup that can cope with the bumpy surface, but not allow us to lose too much downforce from excessive body roll. While on the aerodynamic side, we are looking for the best all-around compromise that will give us sufficient downforce for the low- and mid-speed sections. But we also must be trimmed out enough to run competitively on the straights. Lastly, as this is not a laboratory experiment but real world, we also have to ensure that the downforce level is enough to make the drivers feel comfortable over the 12-hour race distance.

“Another tricky aspect to Sebring is that if the wind picks up, the cars are normally subjected to a side wind in Turns 14, 15 and 16, which makes it difficult to get the exit out of Turn 16 just right. Turn 16 is a slow corner leading onto a long straight, making it critical to get right in terms of overall lap time. It is also the finish line straight so, as we have seen in the past, you do not want to be lacking here at the end of 12 hours of close racing.”

The final stage of preparation for the “36 Hours of Florida” involves more than a month of planning for the three-day event.

“Apart from car preparation, the planning of spare parts is also something that cannot be overlooked,” Hayes noted. “If something is going to break, it will be most likely at Sebring due to the aforementioned high mechanical loadings. Therefore, you must be ready with the parts in the pit lane to make quick changes during the race and in the trailer to be ready for the lead-in to Sebring. Although Sebring is no different from our preparation at other circuits, you always tend to go over the list a few more times as we all know that this circuit will be difficult!”