Verizon INDYCAR Series
From Road Course to Oval, Changing Cars to Fit the Tracks Part 2
After discussing why teams must convert from one track set-up to another, here is the breakdown of the teams going through the process.
First, the team removes all the suspension pieces and has them crack tested. Each corner of the car must be rebuilt. And, because the car will only be turning left on ovals, each corner must be built differently to effect the steering ratios for the loads in the corners. That requires stiffer shocks and springs for the anti-roll bars that are used on the ovals. The shock absorbers have to be completely rebuilt, or revalved, so that they are different from the right to left to fit the oval track. The weight of the car is carried by the right side on an oval. Even the tire pressures, easily changed at the track, can vary from right to left. While the right front recommended pressure might be a psi of 32, the left rear might be at 26 psi.
The camber, the way the tires are angled, are also different. On a road course, the tires and suspension are virtually the same from left to right. But on an oval, where a driver might reach 5 G’s in the corners while only turning left, the tire must flex to make contact. On the straights, the tire runs on the inside edge and then squats from the G’s in the corner, ideally making full contact with the racing surface. You can have negative camber on the right side and positive camber on the left side to achieve this on an oval.
Around the center of the car, the ballast is changed to adjust the weight distribution. The pick-up points in the fuel cell have to be modified to pick up in the corner while the driver is only turning left. And all ovals require the car to be fueled on the driver’s left but any road courses that run clockwise need the car to be fueled on the driver’s right. The buckeye, the opening for the fuel tank, must be adapted from one side to the other. The side not used is covered for aerodynamic efficiency.
While the gear box remains the same, the gears can vary in use on an oval. Usually, there is a 5th gear for passing and a 6th overdrive gear for fuel economy. On road courses, there are six forward gears and one reverse. The left rear tire is unlocked for a tight corner. But on an oval, the rear tires are locked together so that when you have stagger, that is the inside left tire is slightly smaller in circumference than the outside right tires. As a result, when you draw circles around the track, the right side traces a larger circle than the left, giving the car an arc when it accelerates.
The most visible change from a road course to a superspeedway car is the significantly smaller, sleeker wings for the big ovals that produce downforce but with a lot less drag. At some tracks, IndyCar allows the teams to change the angle of the flap, a horizontal piece across the rear wing. But once in line to qualify and passed through Tech Inspection, it can’t be altered. The racecar for qualifying is designed to have a minimum amount of drag, forfeiting some downforce and putting the car on a knife’s edge to, therefore, get the most speed out of a lap. But for the race, the car has downforce added and that increases the drag, a necessary evil to make the car more stable in turbulence from other cars on the track.
Of course, all these settings that are modified for the ovals affect the stability of the race car over a fuel stint. The more the car slides, the more the tires will wear and could require the driver to hold on for dear life to make it to the targeted lap for pitting.
Kyle Moyer, the Competition Director at Team Penske with four drivers and Simon Pagenaud’s race strategist, said, “It takes us about 120 hours to convert a road course car to an oval set up. We could do it in one day if we have to with about six guys.”
At Rahal Letterman Lanigan Racing, which is a one-car team supporting Graham Rahal, Team Manager Ricardo Nault explained, “We have three cars in rotation. We have one used for the superspeedways at Indianapolis, Texas, and Pocono. We switch to our road course car for Detroit. And, because we ran a second car at Indianapolis this year, we converted that car from road course to oval and back again. After Texas, we set aside the superspeedway car until we ran it at Pocono in August. Fingers crossed we don’t write off a car in an incident. But if we did, we can convert a car from road course to superspeedway in a day.”
Many teams struggled during the 2017 season due to multi-car accidents such as at Phoenix and Texas. There were some tubs, the driver’s cockpit also known as the safety cell, which had to be sent back to Italy to Dallara, the chassis manufacturer, to be repaired. That reduced the number of cars teams had to work with and in some cases, they had to convert one car from oval to road course or vice versa.
“There is enough time to convert a car from oval to road course,” said Larry Foyt, Team Manager at AJ Foyt Racing, running two drivers. “We can do it in a day if we have to with a number of our guys working on it.”
While the drivers leave after a race weekend and can relax, spending time with their families, the dedicated crews are putting in the long hours at the shop converting the cars for the next event. When asked about having a day off, they will say, “What’s a day off?”
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