Tuning Guide [Tip: Make one adjustment at a time and test it. If you make several adjustments at once, it can be difficult to isolate the effects of each adjustment, as one adjustment can cancel out another.]
Springs
The purpose of the springs are to control wheel movement and keep the tyre in contact with the road over bumps and undulations. Stiffening the springs front and rear will reduce body roll and make handling more responsive, but cause a loss of traction over bumpy surfaces. Likewise, softening all of the springs will give more grip on bumpy tracks, but increase roll and reduce responsiveness. You can also use the springs to affect the car balance. You can reduce oversteer by stiffening the front springs or softening the rear. Likewise, you can reduce understeer by softening the front springs or stiffening the rear. However, be advised that changing just one end also affects fore/aft weight transfer. By softening the front springs, you'll also get more dive under braking. Softening the rear will give you more rear weight transfer under acceleration, which can give you more traction on the rear wheels in straight-line acceleration.
Ride Height
A lower ride height lowers the center of gravity, which reduces weight transfer during cornering, acceleration, and braking. The reduced weight transfer improves cornering. Also, by lowering the front end and raising the rear, you can improve high speed stability and increase downforce by preventing high-pressure air from building up underneath the nose of the car. For rear-wheel drive cars, you can improve rear traction under acceleration by increasing ride height, since maximum traction can be obtained with the maximum amount of weight on the rear tyres. Generally, you'll only want to do this in the acceleration tests, since it will hurt cornering performance, and never with front-wheel drive cars, since the driving wheels will be losing grip.
Dampers
The purpose of the dampers (also called shock absorbers) is to dampen the oscillation of the springs. The dampers not only dampen spring oscillations, but they also affect handling during transient conditions (such as the entry and exit of turns), but not steady-state conditions. Softening the dampers reduces responsiveness, and likewise stiffening the dampers will increase responsiveness. However, if they are too stiff, they can lead to a loss of suspension sensitivity and increase the harshness and bumpiness of the ride. If they are too soft, it will cause the handling to feel mushy. You can reduce understeer during corner entry and exit by softening the front dampers or stiffening the rear. Conversely, you can reduce oversteer in the entries and exits by stiffening the fronts and softening the rear dampers.
Camber
Camber is the angle the tyres make with the road and is measured in degrees. Tyre grip varies with the camber angle, and ideally is maximum when the angle is zero. However, the maximum grip is found with a small amount of negative camber because of tyre sidewall deflection (when the top of the tyre is tilted inward it is called negative camber. Also, as the car rolls in a turn, the suspension movements themselves causes some adverse camber change. These combined effects mean that for maximum cornering power you need to have some amount of negative camber. However, too much camber will cause you to lose grip because the outside edge of the tyre is being lifted off of the pavement, reducing the contact patch.
So to summarise, as the camber angle increases from zero, cornering grip improves to a point, then falls off. Here is a method, though a bit tedious, that finds the optimum camber settings. First, here's a brief reminder on oversteer and understeer. Oversteer is when the back of the car wants to slide out and is caused when the rear tyres have less grip than the front. Understeer is the opposite: the car doesn't want to turn into the turns because the front tyres have less grip than the rear. We'll use this to dial in the camber. To find the best camber, start off by adjusting the other settings first. Then adjust one end at a time, using the car's balance as feedback. That is, adjust the front camber to the point of maximum oversteer (or minimum understeer), and the rear camber to maximum understeer (or minimum oversteer). To finish it off, go back and tweak the rest of the settings if necessary (usually a small stabiliser adjustment is all that's needed, if any). On a final note, if you make radical suspension changes you may need to readjust camber.
Stabilisers
The purpose of the stabiliser (also known as the anti-roll bar, or anti-sway bar, although I prefer anti-roll bar because it can very well destabilize a car and has nothing to do with sway) is to resist body roll in a turn, much like a spring. However, unlike the springs, they do not come into play on two-wheel bumps or on fore/aft weight transfer. Stiffening the stabilisers front and back gives more responsive handling and less body roll, but can upset stability on a bumpy track by transmitting loads from one-wheel bumps to the opposite wheel. Likewise, softening the bars all around can increase body roll and reduce responsiveness, but make the car more stable on bumpy tracks. Because the stabiliser bars are fairly independent of other chassis settings, they are ideal for fine-tuning car balance. You can reduce understeer by softening the front bar, or stiffening the rear. You can reduce oversteer by stiffening the front bar or by softening the rear.
Troubleshooting
Here's a quick reference guide to solutions for some common tuning problems.
The solutions to each problem are listed in order of priority, the ones listed
first are usually the first ones to try.
|
Oversteer General |
* Stiffen front stabiliser bar or soften rear stabiliser. * Stiffen front springs or soften rear springs. * Decrease front downforce or increase rear downforce. * Install hard tyres front, soft tyres rear. |
|
Oversteer Entering/exiting turns |
* Stiffen front dampers or soften rear dampers. |
|
Oversteer At high speeds |
* Decrease front downforce or increase rear downforce. |
|
Understeer General |
* Soften front stabiliser bar or stiffen rear stabiliser. * Soften front springs or stiffen rear springs. * Increase front downforce or decrease rear downforce. * Install soft tyres front, hard tyres rear. |
|
Understeer Entering/exiting turns |
* Soften front dampers or stiffen rear dampers. |
|
Understeer At high speeds |
* Increase front downforce or decrease rear downforce. |
| Handling sluggish and unresponsive |
* Stiffen springs all around. * Stiffen dampers all around. * Stiffen stabilisers all around. |
| Handling too harsh and sensitive |
* Soften springs all around. * Soften dampers all around. * Soften stabilisers all around. |
| Bottoming |
* Increase ride height * Stiffen springs all around |
| Low grip |
* Install softer tyres. * Increase downforce all around. * Lower ride height * Soften springs all around. * Soften dampers all around. * Soften stabilisers all around. |
| Loss of grip on bumps |
* Soften springs all around. * Soften dampers all around. * Soften stabilisers all around. |
| High tyre wear |
* Install harder tyres. * Eliminate excessive understeer or oversteer. * Adjust camber. * Soften springs. * Soften dampers. * Soften stabilisers. |
