To begin successfully creating an oval race car setup, you need to understand the basics of your components as well as how to read your tire temperatures after you have driven laps without sliding or overheating any of them. Here I will explain where to start and get your car on the track.
The first thing I do when creating a setup is detach the front (and rear) sway bar, then I use the left bar end offset setting to increase my sway bar gap to a positive number (ex. 10/16") so that I know I have sway bar clearance and will not be pre-loading it while I attempt to make adjustments.
If the sway bar gap is at all less than 1/16" during my setup process, I will change the left bar end offset setting to increase that gap again - I feel good with something like 10/16". If you do not do this and your sway bar gap reads a negative number like -1/16", then your ride heights and spring configuration will mean something completely different and you will probably end up tighter than you expect.
I set all my springs to their lowest rates (that is unless I already know which spring package I will most likely use for the track). For the trucks and Impala B (Nationwide) car, but not the Impala A (COT), I set the LF (left front) ride height all the way to the lowest allowed minimum, and set the RR (right rear) all the way to the maximum allowed. For the COT, I have heard it is generally best to keep the ride heights the same from left to right, so both front corners while both rear corners are the same ride height.
- A lot of the time my truck and Impala B ride heights end up something like:
- LF: 5" | RF: 6"
- LR: 7" | RR: 8"
Now, keep in mind - not every track will use this same configuration. Flat short tracks like Martinsville or really fast bigger tracks like Talladega for instance you might find that you want to run the same left-to-right ride heights. I have not yet figured out any specific rule-of-thumb to this yet, but I imagine that the more your car leans on the right side in the corners, maybe you want it higher on that side to compensate and become "level" at mid-turn. Keep in mind this is ideal so that your camber and spring and other adjustments are working together for you to have the most traction if everything lays flat. (It works in my head, disregard this sentence if I just lost you)
I will admt that corner weights still elude me a bit. This is why I have not mentioned them nor will I be truly focused on their numbers at this time. I have been developing some real positive results though when I do pay attention to an overloaded or underloaded corner and balance it out and go off and read a bit more about them. I haven't found a direct relationship to ride heights, spring, and spring perch offset adjustments yet.
Maybe I'm overlooking something simple, but I can change my springand/or spring perch offset and still have the same corner weight. Once I fiddle with ride heights (via the spring perch offsets) alone for wedge, that's when I notice the corner weights start changing.
So now, you have your car sitting there with soft springs, front sway bar all unhooked and your ride heights are in the general configuration you are expecting them to be for that track. What do you do now? Take note of what your cross weight is. I like to start with 50% unless I already know that track and spring package and what it calls for.
Before going out on the track, I will generalize some of the setup items. My shocks start at 16 all the way around for both bump and rebound. This is the middle-ground and they won't be any softer or harder than any of the other ones. This is purely personal preference however. Some guys (myself sometimes included) will set up their car with both bump and rebound set to zero so they can feel their car without any damper influence. 16/16 shocks (aka a 50/50 shock) are a really good start normally for a pretty new person doing this.
Next, I will usually set my LF and RF cambers. LF gets about +4.0 degrees, RF gets about 0.0 degrees to start. I will readjust after a run based on my tire temperatures, and this is purely a preliminary general starting point for me. Just remember, adjusting your camber at rest can change your ride heights and cross weight (remember, change camber while your front sway bar left side is unhooked and your sway bar gap is a positive number - as if you intend on changing ride heights).
Caster is something that is extremely critical but without it really feeling like it. If you run a wheel without force feedback or minimal feedback, then you probably won't even notice any changes made here and you will never know whether it is slowing you down or not. For me, I am particular about this. If your left arm gets tired while driving, you might have too much caster in general (this is not always true). When I load somebody else's setup and I see any negative caster setting, I won't even try it out. This will make the car feel like it wants to turn the wheel, but the car doesn't want to really turn, which will give the driver a false sense of a push. I start my setups with +2.0 on the LF and +4.0 on the RF. The smaller, tighter the track, the smaller the RF caster setting. This isn't exactly "the right way" to do it, but it's a good start. Never ever ever do you need negative caster. You will never be fast with it. Don't be fooled by others - just trust me. There is a lot about camber and caster adjustments and how they go together. This is the topic of many of my studies.
Now I will probably go out and run a few laps. If it's driveable and not uncomfortable, I will run it at least to 1/2 tank of gas (I start out full, not with 1/2 because it will change ride heights for pre-race inspection). This will give me not only an accurate indication of how many laps I can run on a tank once I've gotten that far, but also I will know what it is like with that many laps on it.
From there, make your adjustmens. Keep practicing, keep making adjustments and when you decide to race, you will at least have a car that will last without spinning you out.
This is a basic start to creating an oval setup and I hope this information helps. As I develop more techniques or tips, I will add them.