To get the most our of an IndyCar on an oval is a tough chore. Not only must the driver wrestle with the immense g-forces and dare to race hard with the competitors and concrete walls so near, but the car itself is put under immense, contradictory stresses that require a very specific chassis and aerodynamic setup. On the unforgiving oval, setup trumps driving ability since the margins between a quick lap and a heavy crash are so thin.
Finding the Sweet Spot
On the oval, big slides are very dangerous and always slow. So, the car has to be balanced so that the rear end is planted, all without much understeer. In other worlds, the narrow parameters an oval-running IndyCar has to function within means the aerodynamics, chassis balance, tire wear, and brake cooling have to be given plenty of consideration.
An oval car requires a less compromised setup than a road course car. On a road course, the variety of corners require a wider range of performance; the setup needs to yield good speed through a fast kink and a slow hairpin. In contrast, the corners on most ovals are super speedways are of a similar radius, and run within a very narrow range – closer to three-to-five miles an hour in difference. Therefore, it’s important to make sure a near-perfect setup is achieved.
Changing the Balance
To find this balance, you change the balance front-to-rear with the anti-roll bars. If a car develops an understeer problem due to tire wear, you can shift more weight to the front outside tire to try and remedy the situation. When the fuel loads decrease, the amount of weight over the rear end lessens and the handling balance must be adjusted to compensate. This means the driver has to constantly adjust the car’s balance to perform throughout the race.
Fine-tuning the balance is found through the weight jacker, which manipulates the ride heights on either side of the car, thereby limiting or encouraging weight transfer. If, for instance, a car is reluctant to turn in, more weight can be shifted towards the left side of the car. If a car is suffering from a little too much oversteer, weight can be shifted to the outside to keep the rear tires planted under acceleration.
The aerodynamic elements are kept plain and unobtrusive for the oval. Road courses call for more downforce and more complicated wings, which also generate a good deal of drag. The oval wings contrast the road course wings in their simplicity. This simplification must be made so that a decent top speed can be met without sacrificing stability.
As oval cars are only responsible for turning left, the cars are designed to turn slightly without any steering input.The camber of all tires are cantered over to the right to provide the widest possible contact patch when cornering. This facilitates turn-in, but it also requires plenty of strength to keep the car straight. For similar reasons, the headrests are not of equal size. The right side bolster is fitted with a thicker pad for the driver to prop their heads against. With modern IndyCars, even the strongest drivers would have serious difficulty keeping their head upright without assistance.
As the brakes are both needed less and the car is regularly traveling at a higher speed, the brake ducts are narrower compared to those of a road racing setup. This is because to get the carbon rotors to work effectively, they need to be kept within a narrow temperature range. All the air traveling through the ducts at those speeds can over-cool the brakes, so the ducts must be kept relatively small so the brakes stay warm enough.
All in all, setting up an IndyCar for an oval is a demanding task, and whereas a bit of skill can help make up for a car’s deficiencies on the road course, going quickly requires near-perfect balance, good tire wear, stability and very little drag. Whereas a road course setup has to accomodate for a variety of corners and some leeway is given, the corners on an oval are all taken at roughly the same speed, and so the window narrows. On the oval, there’s no wrestling with a recalcitrant car – that spells a nasty end. Only when that ideal setup is found can a driver muster the courage to consistently drive within a hair’s breadth of the unyielding concrete walls.