Advanced Quikfix Guide

An in-depth guide to setting up your race car.

1) Terminology

Push- Basically, it means that the front wheels of a car are losing traction. Also known as understeer. The characteristics of "push" are that the front tires heat up more than the rear, or overheat. The driver is aware of it by attempting to take a corner, but no matter how hard or far he turns the steering wheel, the car apparently will not turn as far as it should.

Loose- Oversteer, or, the rear tires of a car are losing traction. The characteristics of this are that the rear tires overheat or heat more than the front tires, and the car will "over steer", or turn more than the driver turned the wheel. Very often this will result in the car going sideways.

Wedge- Crossweight.

Downforce- The downward pressure applied to a section of a car derived from the force of air flowing over that portion.

Center-of-gravity (CG)- Where the center of all the weight is on the car. In another words, if you had a giant pencil, what point of the car could you balance it on. On a Winston Cup car, it would be slightly to the left, not the exact center of the car (see below).

2) Weight- This is the FIRST thing that should be looked at when setting up a car. If you have the weight wrong in a car, no amount of adjusting tire pressures, shocks, struts, or spoilers is going to help you. This must be close first. And weight directly affects the thing that makes your car handle anyway...traction. And traction is the amount of slippage a tire has between it and the road surface.

How can we get more traction? Only 2 ways: friction and weight. Friction can be explained by this; if the tire were a gear, and the road surface was a cog rail, you would have no problem with friction...the gear teeth would mesh with the cog and create a direct, no-slip contact. However tires adhere to the road by the pliable rubber clinging to the rough road surface…if the road were plate glass, you would never make the first turn! Weight actually adds to the friction by providing more "push" on each tire. The tire with the least amount of weight/friction is going to be the first one to lose traction.

So lets get into the specific weight settings for a car.

Left-Bias- This tells you how much weight is positioned on the left side of the car. On an oval, it is necessary, on a road-course, you want it to be almost even, or slightly biased to whatever side has the most corners. What does this do for you? Moves the center of gravity (CG) to the left. This has the effect of allowing the car to corner much easier on an oval course. By placing weight on the left side of the car, it offsets some of the weight shift that happens when the car corners, and centrifugal force now takes effect. Centrifugal force pushes the weight to the outside of the corner.

Nose-weight- This is the amount of weight which goes on the front of the car, as opposed to the rear. This is rear-bias in NASCAR Racing. What this does is put more weight on the wheels in the front or rear of the car. On a large oval, you want more front weight, because the rear spoiler is providing more weight via the airflow to the rear. On a short track, you will want more weight on the rear, as the rear spoiler is not providing so much downforce.

Cross-weight, or wedge- This is slightly different, as this provides weight diagonally across the car. The NASCAR Racing game is a bit simplified, as on a real race car, you can take wedge in or out on all four corners. So what does it to? Adding wedge places more weight on the LR and RF…thereby keeping the car from getting loose. Taking out wedge adds more weight to the LF and RR, preventing push. The key is the left side tires getting more weight (whether front or rear), thereby keeping that end of the car stuck to the track.

3) Tires- Tires are a very important part of setting up your car. Tires play a role in the tire wear, aerodynamics, handling, cornering, and fuel efficiency of the car.

Air pressure- Air pressure adjustments are one of the biggest ways to change the handling of the car, especially during a race. If you lower the air pressure on a tire, it has several effects. First, it increases the rolling resistance of the tire, especially on radials. What is this? Well, if you’ve ever driven with a flat tire, that is rolling resistance. The tire rubber is being bent more because of the lower air pressure in the tire, thereby causing friction. This will in turn lower the fuel mileage.

The next effect that lowering tires has is by lowering the car, and thereby the weight over the tire. This has approximately the same effect as changing to a softer spring/shock. First, there is now more weight on that wheel, making it stick to the track more. The tire now rides lower, and has more give, so "moving weight", as when the car corners, now has more of an effect on that wheel. Since the tire gives more, the weight transfers a little slower to the tire as well. Extremely low tires will give the car a "mushy" or "wandering" feel.

The other effect that lowering the air in a tire has is increasing contact patch. Ever noticed how a flat tire balloons out at the bottom? This is the same thing. A tire with more contact patch will stick better in the corner, as it has more surface planted on the ground.

Raising air pressure has the opposite effect: increases contact patch, lowers rolling resistance, and decreases the weight on that side of the car. It also transfers weight faster to that tire, but less of it.

Since you have a tire on every corner (with any luck) this makes "on-the-fly" adjustments during the race quite easy. Here’s how it works…

Loose going into a corner- Raise right-front tire pressure and/or lower right rear tire. When you are going into a corner, the weight transfers to the front and right side of the car, due to deceleration and centrifugal force. Raising the right front tire decreases the amount of weight that transfers to it, and thereby keeping more weight on the left-rear of the car. Lowering the right rear tire makes the weight transfer much slower to the right side of the car, and allows more weight to stay at the rear, for a longer period of time.

Loose exiting a corner- Raise left front tire and/or lower left rear. Acceleration and straightening the wheel now transfer weight back to the left/rear of the car. Raising the left front keeps more of the weight back on the right rear, and lowering the left rear keeps more weight at the rear, and slows the transfer of weight to the left side. See how this works?

Push entering a corner- lower right front and/or raise right rear. Car weight transfers to the right front, as we said, so lowering the right front allows more weight to transfer to that side. Raising the right rear transfers more weight, faster, to the front of the car.

Push exiting a corner- lower left front and/or raise left rear. Like we said, more weight is going to the left/rear of the car. Lowering the left front places more weight, for a longer period, on the front of the car. Raising the left rear prevents the weight from going to the left/rear of the car.

As you can see, tire adjustments can be very critical during a race, and can make the difference between winning and losing.

Tire wear- The temperature of a tire, and the tire wear is also governed by the air pressure. A lower tire will have more temperature than a higher pressure one, because of the flex in the sidewalls, however, it will wear out slower, as it has a bigger contact patch and is not sliding as much. A higher tire will have less temperature, unless it starts to slide, and then it will start heating real quick. It will also wear more.

Stagger- Stagger is the difference between the right and left side tires. What this does is allow a car that is on an oval to corner better, as the right side tires are taller, and thereby don’t have to rotate as much as the left side. It helps keeping the weight more to the left side. Increasing stagger will make the car looser, while decreasing it will make the car push, as it’s not able to corner as easy. A general rule of thumb is: the flatter the track, the more stagger you will need.

4) Suspension- Suspension covers several items; camber, shocks, wheel lock, and we will even discuss springs. Springs are not covered in NASCAR Racing, they are combined with shocks. It is important for you to know how they work differently, though.

Camber- camber is the angle (vertically) that the tire meets the pavement. If you’ve been to a racetrack, you probably have noticed that a race cars tires are canted over at an angle. This is to allow the tire to be in full contact with the road when the car is in the corner, and the weight has been transferred to the outside of the car. That’s why it’s important to take the measurement of tire temperature at the end of the corner…this gives you an advantage over a real driver, as he cannot see how the tire temperature is in the corner. If you have one side of the tire hotter than the other, change the camber so that less of that side of the tire is touching the racetrack. That will even out your temperatures.

Shocks- Shocks and springs both work at dampening the wheel travel as the car moves over the race track, but in reality, only the springs make a difference in how high the car rides above the pavement. The shocks only provide more or less dampening. These elements are both critical, however, in how the car handles at each and every race track, because you can adjust how the car handles at each wheel. For this discussion we will assume that the shocks and springs have been combined as they are in the racing simulator.

So how does this work? Basically, the same way that adjusting tire pressure does. If you add more spring/shock to the right front, the ride height increases, moving weight away from that wheel. As well, with the stiffer ride, less weight moves to that wheel going into a corner, but it does it faster. On a real car, you could put a stiffer spring in that corner, which would keep more weight away from that wheel, but put a softer shock there, which would allow the weight to transfer to the wheel more slowly, and keep the weight there longer. In the simulator, this is not possible. To see the rest of the adjustments, refer to the discussion of tire air pressure adjustments above…adding more shock/spring has the same effect as adding more tire air pressure.

5) Aerodynamics- Aerodynamics is still a very misunderstood term, as many do not understand the many facets of airflow and downforce. Unfortunately, in this discussion, we are somewhat limited, as the simulator does not take advantage of all the ways of creating better aerodynamics as on a real race car.

Front air dam- The front air dam provides two things, downforce over the front of the car, and resistance to air flowing over the car. Lowering the air dam creates more of a "lever" on the front of the car, preventing push. Raising it makes the car push more. However, on the flip side, raising it allows more air to flow under the car, and therefore less resistance. On a real race car, the entire front hood and fenders can be widened to help provide more frontal area for airflow to work on and make downforce. We are limited in this area to just the front air dam. One aspect not to forget is that a car with more resistance will also use more fuel.

Rear spoiler- raise the rear spoiler to create more downforce on the rear, and prevent the car from getting loose. This will also create more resistance to the airflow, however, slowing the car. A higher spoiler will also alleviate another car from getting your car loose by riding under the spoiler, by providing more downforce even when another car is drafting. A low spoiler will allow the car to go faster, but when another car is in the draft, it removes even more downforce from the rear of the car, and can get you loose real quick!

Ride height- raising the car up by using springs and tire pressure also lowers the resistance, as it allows air to flow smoothly under the car. You can also raise the rear of the car, which puts more of the rear spoiler and decklid in the air, and creates more downforce on the rear.

One thing that is used by real race drivers on speedway races is drafting, and taking air from another car. Drafting works by driving one car up to the rear of another car, and therefore both cars now can use the displaced air to go faster. The front car no longer has a swirl of air behind the car, as it is now picked up by the rear car. The rear car no longer has to displace the air, it picks up the airflow off the rear decklid and spoiler of the front car. You do not need to be inches away from the front car to create a draft, a half-car length or car length is sufficient.

You can remove the airflow from another car, making it unstable, by driving up close to the side of another car. This will create a low pressure area that can essentially "suck" a car sideways. This can be used to make a pass, if you can make the other driver have to slow to regain control of his car. However, this move should only be attempted by experienced drivers, as it could be your car which gets sucked around and take the long trip to the wall!

6) Gearing- Gearing is the last thing we will discuss. Gearing works in several ways, acceleration, engine RPM and torque, and fuel mileage. You should make your first several gears capable of giving you the optimal 6500-7000 starting torque band. Know what speed you will be traveling the race track under caution, and make your 2nd and 3rd gears capable of giving you this band. Make your first gear capable of giving you dead stop acceleration, as in starting off of pit road. You may need to change third gear slightly if you will be downshifting at the race track, to allow you to get a good RPM band coming back up to 4th.

Your 4th gear will need to give you that optimal torque coming off of the corner, without going over 9200 rpm at the end of the straightaway.

This brings us to the last part of the discussion…don’t forget that your fuel mileage also depends on your gearing. If you feel that you may need to gain on fuel consumption, lower the gearing a bit. You will suffer on the power coming off the corner, but it may give you that last little bit to make one less pit stop. If you need to conserve more fuel during a race, let off the accelerator quicker going down the straightaway, and let it coast into the corner. You will not lose much time doing this, and it will help in the fuel consumption. As well, get on the accelerator later in the corner.