Hard to believe: the last race of the season–the Petit Le Mans–is this weekend. For Risi Comp, the race season and the 458 era will end at Petit Le Mans. Petit has always been a good race for us…we won the first Petit Le Mans with a 333SP and have enjoyed success there ever since. As always, the inside look at what Risi Comp faces this weekend comes from Rick Mayer, Team Engineer, who provides engineering and tactical insight into the last endurance of 2015 for the Risi Competizione team, Ferrari 458, and drivers. Well worth your time to read.
The Petit Le Mans 2015-GTLM Overview.
by Rick Mayer.
The Track: Road Atlanta is one of the favorite tracks for Risi Competizione and most of our drivers. Favorites tend to be the ones you’ve had success at, and this is no exception. It’s a fast track layout with a variety of different types of corners, it’s technically challenging for both drivers and engineers, and very satisfying when you get it right.
The requirements to go fast at Road Atlanta are always the same. You need a good platform for the high-speed corners – Turn 1, the Esses and Turn 12. You can gain a significant amount of time using the apex curbs effectively at Turn 3 and the exit curbs of Turn 5. There’s some real curb jumping at Turn 3; it’s a good corner for photos. The curbs at both Turns 7 and 10 also yield lap time. However, as much as you need the curbs for a quick lap time, you have to exercise caution as using them repeatedly here can lead to failed drivetrain components. It’s a long 10 hour race and you need to be somewhat kind to the car; you have to finish to win. Top speed is very important as there are few places to pass.
Setup: Stiffer (springs and anti-roll bars) is better for platform support but curbing is so important here, it’s a compromise. A stiff setup also makes cleaning the pick-up off the tires easier as you can load the tires harder. With such a big field, the number of times that a GT car may have to go off the racing line, and therefore experience pick-up, will be increased. Dampers that give support, but blow-off on the curbs, can make a big difference here, not just in lap time but longevity of the drivetrain components.
Top speed and downforce level will be based on peer group straight speeds. Greater overall downforce is the quicker way around the track and better for tire life, but you can’t let the competition drive around you on the straight. Passing will be difficult, especially in GTLM with the 8 super-competitive cars from 4 different manufacturers. The best passing spot will be braking into Turn 10. However, if you can’t keep up on the straight you won’t be in a position to out-brake someone into Turn 10. The track isn’t particularly hard on brakes, but you need the brakes to last the 390+ laps that the GTLM cars will run during the race.
Keeping the car low to the ground (low running ride heights) is a challenge at Road Atlanta. Your options are to run very high ride heights (Sebring track levels) or stiff springs or bump rubbers to hold the car up in the large compression areas. The main issues where the car will contact the track are the bumps in the middle of Turn 1 (left rear) and the curb in Turn 3 (right side), either the curb itself or the landing from launching from it. Your ability to setup around these features will ultimately determine how low you can run the car.
The Race: Traffic will play a large role as always at Petit with a 37 car field. Keeping out of trouble will be crucial for success. With a 10 hour race pit strategy is easier as you’re not forecasting the leaders lap count or time to finish.
Pit work needs to be only fuel, tires and driver changes, with the occasional addition of engine oil. Anything extra or slow pit work will put you at the back of the field quickly.
Qualifying is less important at these long races as our usual 2h 40 minute events, but keeping up in the lead pack will always be vital due to the level of competition and how difficult it is to pass at Road Atlanta. The current caution rules should keep the GTLM front-runners on the same lap. The current BoP (balance of performance) has the Porsches and BMWs with an overall advantage and Corvette with a top speed advantage.
But don’t count us out. A red Risi Ferrari has fared well at Petit in years past, it’s one of the team’s more successful venues. Let’s just hope our luck continues and we can end the season on a high note.