I really want to write a monologue on how I hate change. Specifically, change from the standard. I think we can all agree that a 1.5 mile cookie-cutter is the standard in NASCAR tracks. Las Vegas is the standard of the standard. Fairly new surface, progressive banking . . . a set-up builder’s dream.
I’m going to give you a crash course on 1.5 mile set-ups. Look at it as an equation. (speed)/(handling)=x. Let the differential between speed and handling determine the behavior of your car. There is a very fine line between milking speed and flat-out burning rubber. Your goal is to get the speed out of the car without compromising handling. Let me add to the equation now. [(speed)](length of run)/(handling)=x. I look at x as ability to control/push the car as needed. Every sim-racer on iRacing will have a different level of x. As a driver, crew chief and egotistical maniac, you need to push x as hard as possible.
For those of you who have absolutely no idea what I am saying, keep the car under your control. I can’t tell you how you should drive the car. You need to drive the car to YOUR limit on 1.5 mile tracks. Let me use this to transition to a set-up.
I hear too many people complain about getting loose through the tri-oval at these tracks. On a scale of 1 to annoying, it’s a migraine. The easy fix to this is adding ballast. Ballast is, for all intents and purposes nose weight. Sure you are giving up speed, but you gotta increase handling to return to your x.
This is a good place to start. Ballast will improve the overall control of the car. However, this will take some raw speed out of the car. I am going to give you numbers that you can take and start with. These numbers will not give you the speed to be competitive, but they are a good starting point.
First, add 30” ballast. This will increase nose weight and add the control you need. The next step is setting cross weight to a good starting point, let’s say 60.0%. This tightens the car overall. I also set both rear springs to 200 lbs and the rear track bar to 6.500 each.
The above information provides a good platform to begin the test. I started looking for speed by adding LR camber. I found it reduced the snappiness of the exit. It just felt better to me and I don’t need to be overly concerned with LR wear. I also set the truck arm preload to about a 15.0 setting. This stabilized the rear of the car by removing twisting force on the rear suspension.
Even though the car became remotely controllable by doing the above, I added front spring on both sides to give a little bit more travel. If you find the car is a little tight on entry to center, don’t throw the kitchen sink at it (yet.) I would go about removing a little front brake bias. It will give the car more rotation on entry without killing exit speeds. Reverse the process if you are a tad loose on entry.
Always remember that the easiest way to change attitude is cross weight. The fixed set isn’t remotely close to being correct for a short run. Once the car behaves, stop adjusting. It doesn’t matter if you are a few tenths off because you are going to gain speed from correct balance anyway.
Be sure to send in your questions in the comments or as a PM to Eric Isenbeck on the iRacing forums. Next week is Bristol, the home of 2400 lb RF springs and such. I’ll explain why teams do this in the next article as well as how to preserve tires on the concrete.