A lot of people have asked me over the years, what is it like to plan, prepare for and run a 24-hour sports car race. It has changed somewhat over the years from the days of the Porsche 935 at the 1981 Daytona 24 Hours. Many of today’s cars are way over-engineered for what is required, reference IMSA DP cars. Technology is relatively low, and if you build them correctly, they can be driven very hard for a long time. Restrictors, rev limits, boost limits, etc. limit the amount of potential damage that can be done by pushing too hard. Likewise, factories like Toyota, Porsche and Audi, spend hundreds of millions of dollars building and preparing very complex cars to run at Le Mans flat out for 24 hours. Cars pretty much run lap times in the race similar to what they qualify at.
This was not the case in the day of the Porsche 935. Preparation and how hard you pushed (or drove) were limiting factors to finishing and or winning. There were no restrictors at all, and engines run at high turbo boost pressure, would usually fail. The Achilles heel of the engine was the cylinder head gasket and high boost pressure created a lot of heat which was not good for engine life. High boost was also detrimental to the turbos. We would routinely qualify at one speed, and then race at a much slower pace, especially for the long races. The fine line was always to run as hard as you could, but not break anything. The Porsche 935, however, was more reliable than almost anything else running. Put together correctly and driven smartly, it was a very reliable car.
