Rick Mayer on being successful at Lime Rock Risi Competizione Race Engineer Rick Mayer gives his thoughts and insights on what it takes to successful at Lime Rock Park, site of this weekend’s American Le Mans Northeast Grand Prix.
Lime Rock is the shortest permanent race track on the American Le Mans Series schedule. It is approximately 1.53 miles and has only two left turns including the chicane that IMSA runs. Being quick through the chicane requires being good on the curbs. If you can run a lot of the curbs in the chicane, you can gain a significant advantage.
You need to set the car up basically for an oval and almost disregard the two left turns. The 430GT needs to be good going into T1; this braking zone is one of the few passing opportunities at Lime Rock. But the T1 braking zone is also quite bumpy, not harsh but bumpy in an undulating way. A lot of the corners have a mix of concrete and asphalt through the center, and so the grip changes as the tarmac changes; the long first turn is no exception. It’s particularly important to get a good run down the hill into the last turn as this leads onto the longest straight and to the passing area at the entrance of T1.
This last corner is the fastest corner at Lime Rock with a minimum speed of about 110 mph. It’s flat (full throttle) for the LMPs but not the GT2s. You need to run the exit out to the edge of the track, but get too much dirt and not enough track and you’re in the tire wall at the exit which is what happened to our No. 61 Ferrari last year.
We’ll run some tilt here (left side higher than the right) to keep the left side off the ground while still keeping the car as close to the 50mm minimum ride height as possible. Depending on the car, you’ll also run some cross weight. Normally more right-front weight will let you trail brake longer into T1 without inside front wheel lockup. Cross weight is good as long as it doesn't make the car oversteer on the rights; RF weight also increases LR weight. You run the right side cambers as straight up as you can (the “oval” setup again).
Typically you can’t get positive camber as the car isn’t built for that large of an adjustment. You also have to be careful with tire to fender clearance when going toward positive camber. The Negative camber that we normally run provides upper tire to fender clearance, by tucking the top of the tire into the fender, and the negative camber gain (suspension geometry generated) in bump (compression) keeps it clear of the fender in roll. It goes without saying that you run maximum downforce here; top speed is quite low, about 150 mph. For GT2 cars that means run as much wing (rear downforce) as you can to balance with the front downforce. More downforce (at Lime Rock) increases the exit speed in the last corner and actually increases the front straight top speed. Trimming aero actually reduces top speed here.
Calling the race (race strategy) with the cautions is tricky at Lime Rock because a green lap is so short (about 54 seconds for GT2) and the caution lap is only 100 seconds. If your strategy is to wait for the wave bye (on the cautions) you better hope you’re up in front of the queue on the wave bye or you could get lapped or the green may come out while you’re in the pits. Each pit stop isn’t automatically full service if you want to stay on the lead lap. Each yellow will have its own strategy which is difficult to plan out in advance. For such a short track, Lime Rock presents quite an interesting set of challenges for a race team.
Round Six of the American Le Mans Series is the American Le Mans Northeast Grand Prix, set for 3 p.m. ET on Saturday, July 7 at Lime Rock Park. CBS Sports will televise the race at 1 p.m. ET on Sunday, July 8. American Le Mans Radio will have live coverage at americanlemans.com, which also will feature IMSA Live Timing & Scoring.