I’ve been involved in racing since I was a child. Mostly on the oval side of things, but also in Karting, as well as Spec Miata. Over the past few years I’ve spent my time studying engineering, and building setups for iRacing NASCAR Peak Antifreeze Series teams, as well as building my own setups for rFactor, rFactor2, Assetto Corsa, R3E, and any other racing game I can get my hands on.
Tonight, I’m going to explain the process I go through every time I start on a setup.
When building setups from scratch, it’s very important to think through exactly what you want to accomplish with the setup. “Just make it fast” would be nice in a perfect world, but you need to be a lot more specific than that to build a setup properly, so what are the broad things we know for a fact make setups faster?
Center of Gravity – This has always been a huge effect on speed; the lower the better. Race teams in real life are constantly trying to get a lower center of gravity in anyway possible, because it directly translates to speed and less body roll. How do we accomplish this in a sim where we can’t adjust where our weight is placed? This entirely depends on regulations first!
Let’s say you are in a series that has a ride height rule, for example current NASCAR xFinity Series cars, or the current Stock Car Extreme GT3 mod I’ve been working on recently. We only have one option and it’s a big reason a lot of series have gone away from a ride height rule. Run the softest spring you can possible get away with to get the car as low as possible on track while still being able to pass the regulation off track. Without a ride height rule, it comes down aerodynamic grip versus mechanical grip, and the lower we go ,the stiffer we make the springs to compensate. In a perfect scenario on a completely smooth track we could run a near rigid setup and ride the car a millimeter off the track at all times.
Contact patch is the other key to getting raw speed out of a setup. You can adjust this through camber, caster, toe and tire pressures.
The goal here is to get the majority of the tire in contact with the road as much as possible for maximum grip. You could have the fastest setup in the world, but if you are on -5 degrees of camber, you’re going to have a problem. More caster (the angle of the steering axis) results in more camber gain, so depending on track and different corners you may want more or less to get extra camber on those really tight corners where you crank the wheel, but in general this is at or near max everywhere in every sim.
Camber on the other hand is 100% based on a track to track basis, and always has an optimal number for grip on any given track. We just need to find that number.
We can do this with either tire temps in general, looking for a 10-20 degree hotter inner temp (because it rides on the inside more down straightaways) or even better, through telemetry. Toe in general is added for stability to the negative on the front and positive on the rear (you want to keep this at a minimum so you aren’t scrubbing straightaway speed), on top of this you have adjustments like the ackerman bump steer. I’ve seen no sim that utilizes adjustability, however, so I’ll disregard those for now.
Aerodynamics are another reason the lowest possible ride height is so important. Less air under the car equals more downforce and less drag. Think of an upside down airplane wing. Depending on the track, sometimes you will run more downforce, with wings or ride height adjustments. This is entirely dependent on track and car selection, so when experimenting, start at minimum front and rear values to begin with. In general, you want to lower the car until you start scraping and then bring it up just a bit.
So now that we know the basic keys of going fast, here are my general thoughts I go through before I even start refining the baseline I’ve built.
- Ride Height Rule. Run the softest spring possible, usually with a big anti-roll bar to reduce body roll.
- No Ride Height Rule? Ask yourself is the car/track combination more Aero or Mechanical grip oriented.
- If it’s an Aero Dependent combination, run the stiffest springs possible to maintain max aero at all times.
- If it’s a Mechanical Grip combination, run softer springs and don’t care too much about ride height for Aerodynamic reasons. This is for cars like Street Stocks or Miatas that are not going to benefit from any aero tricks on ride height.
- Find optimal camber and caster for max contact patch in corners throughout the whole track. In some cases, on tracks like Daytona or Indianapolis, you want as little contact as possible for max speed under power.
- Consider how bumpy the track surface is to refine suspension settings.
- Search for a Brake Bias value that provides optimal braking distances and weight transfer balance.
- Camber should always be set at the start of your setup build so you get proper balance and feel during testing laps, while re-adjusting after every setup change. Softer springs will create more camber gain, but in general, the optimal camber shouldn’t change once you have your base together, at least not in a large amount.
- Double-Check everything.
You’ll only get better at creating setups the more time you put into it. It should take less and less time to find the optimal basics of the setup as you learn what works and what doesn’t. This is especially easy with telemetry, where you can see exact information of what the setup is doing when it comes to your dynamic ride height, camber… etc… And not have to rely on driver “feel”. Even I will sometimes build multiple setups per race just to see “maybe this will be a tenth a lap faster then that other one.”
In general, the basics from every setup will always be the same unless something was wrong in the first place. Once you have a good baseline setup for a car, you can take that to every track and just fine tune it for each track.
In most cases, I will have a smooth track setup for High Speed/Low Downforce tracks like Monza, Low Speed/High Downforce like Singapore, and a Rough Track setup mirroring the above combinations for places like Chicagoland and Monaco as well.
If everyone appreciates these kind of articles, I will go in-depth into balancing a setup in the next article, Understeer versus Oversteer, how to account for different parts of the track, and corner types. Leave a comment and let me know what you think!