Track summary
Indianapolis Motor Speedway is one unique race track. Not only because of it’s history in auto racing, but because of it’s shape. It is referred to as an oval track, but the shape is the true definition of a rectangle; Four straights, and four corners all of which are 90 degrees. While it is easy to look at the track map and think that it might be an easy track to setup for (as all corners appear to be identical), that is far from the truth. Each corner may have the exact same geometry as the others, each becomes unique because of the straights leading up to, or exiting the individual corners. Turns 1 and 3 are preceded by the long straights so driven differently than turns 2 & 4 which are preceded by short straights, and after your car has scrubbed a lot of speed. Even though turn 1 and turn 3 are identical in every geometrical sense, you will find that what works in one does not work in the other. The same will apply to turns 2 & 4. That is why I like to describe Indianapolis Motor Speedway not as an oval, but as a road course with four corners, all turning to the left.
Starting your setup
All left hand turns allows you to start your setups (no matter what type of car you are driving) biased to those turns. Moving as much of the weight to the left side of your car will provide more grip to the inside tires while cornering and help reduce the outside tires from becoming overloaded (as quickly) in the corners. Also, moving as much weight to the rear of the car will take load off the front tires, allowing them to provide more grip in the corners. Before you even start tuning your setup, your car is going to be extremely weight biased to the left-rear. The same applies to your suspension setup. Firmer left side spring rates and lower left-side ride heights will be standard. Positive camber on the left side tires with negative camber on the right side will help those tires grip in the corners.
If you need more help creating your own baseline setup for Indianapolis, check out the Setup Developer Tool, which will step you through the process of creating your own baseline setups. Select the “Superspeedway Oval” track type to start.
Priorities
Being a super speedway, speed is what matters most. It is easy to get a car to go fast in a straight line, just reduce the wings. But to get the best speed out of your car at Indy it must be able to navigate through the corners well enough so you can stay full throttle through them (assuming we are talking about an Indy car or similar), or to get back on the throttle as early as possible (for the other car types). Obviously you will want to run the lowest aerodynamic setup you can for maximum speed. Carry only enough wing to make it through the corners without having to lift off the throttle. Those with good mechanical grip through the corners will be able to reduce their aero package even lower, and go even faster on the straights. This – good mechanical grip in the corners for the lowest aero setup – is our goal.
Starting with a firmly sprung chassis will allow you to reduce the car’s ride height, which in turn generates aerodynamic downforce (actually it is more a pulling-down/suction force than downward force). This comes with no negative drag effects like wings do. It also lowers the car’s center of gravity, which prevents the body roll in the corners, allowing the under carriage of the car to generate that suction most efficiently.
Now that you have a basic setup package (springs, weight, height, aero) we can start tuning that setup in search of even more mechanical grip. Starting in Virtual Race Car Engineer‘s Lap Wizard tool, focus on getting your car tailored to your comfort using toe, caster, and anti-roll bars. Then get the ideal tire setup by adjusting your camber and tire pressures. After optimizing your tires you may find that you need to revisit the previous adjustments again. This can go back and forth for some time as the car gets more and more tailored to your individual needs and wants. Eventually you will find yourself with a stable setup that is now pretty darn quick – not lead pack quick, but a good race car setup. Now it is time to tune a little more to see about running with the leaders.
Using Virtual Race Car Engineer‘s Corner Wizard tool, focus first on the exit phase of turns 2 and 4. Your car setup should allow you to maintain full throttle from the corner apex all the way down the two long straights, without risk of brushing up against the outside wall. Be aware; for cars that do not require braking for the corners, the dampers are not as effective as other adjustments as there is no big front/rear weight transfer happening. The car’s differential-power setting, caster, and toe can help you here if the dampers are not as effective. Next, still using the Corner Wizard, ensure your car will turn in to the corners at turn 1 and 3. Again, dampers may not be the most effective here depending on your car type, but the car’s deferential-coast setting, caster, and toe settings can and will reward you.
As you fine tune your setup’s corner entry and exit to each, you may need to revisit those tire temperatures. Again, ensure that your tires are optimized at all times. Take note of the tire temperature at the exit of each corner, not the straights, as they should be optimized for the corners, not hundreds of meters after. You may even be able to reduce that aero package again, which will gain you even more speed although restarting this whole phase of the tuning process.
Alien advice
Above I may have steered you away from the dampers, but now it is time to visit them. While some car types may not brake – or even lift off – for the corners, there is a technique that you can use to further tweak your setup in the corners using dampers; “lateral damping”. Lateral damping is to dampen (or not) the weight transfer moving left to right (and right to left) as opposed to front to rear damping that we practice when braking for or accelerating out of a corner. How quickly the car’s weight transitions from the left to the right of the car can still play a large roll in the entry and exit phases of the corner. As an example; have to much understeer at entry? Allow the weight at the rear to transition faster using a lower compression setting on the right-rear, or higher rebound on the left rear. Conversely, you can adjust the front of the car to slow that side to side weight transfer at the front. The same technique can be applied to the exit of the corners as well.
Gearing is quite important, and often overlooked. Not only should you be tuning the gears to optimize pit lane speeds, and race restart speeds, you may be able to tune your penultimate gear for the corners. As the car scrubs off speed in the corners and engine RPM drops, a quick downshift can put your engine back into it’s optimal power band for corner exit. This then allows you to run a final gear more optimized for drafting and passing.
Altering your driving line to minimize steering friction at specific times can gain you some speed down those long straights. With a good handling car, and some planning ahead by building this ability into your setup, a later turn in point for turns 2 and 4 allows a later apex in the corner. A late apex effectively elongates the following straight, and the amount of time you are accelerating and at top speed. It also means you have less steering angle (which equals friction/drag) in your wheel at a time you want to be accelerating.
Lastly, practice pit stops. A pit stop, even under a caution, is still a time when a few tenths of a second could mean the difference between leading the race or running in a pack of cars slowing you down. I’m not talking about the time it takes the crew to change tires or add fuel. I’m talking about you knowing the exact braking point (both at speed and under caution) to enter pit lane. While others that have not practiced this will either brake to early (giving you a time advantage) or to late (and getting a penalty), you can have it perfected and find yourself running in a position to challenge for a race lead with a little bit of practice.
You can find more setup guides here