This is a guide to help you fine-tune your vehicle in DiRT as accurately as you desire. All of the text is provided in the game, except for the "Laymens Terms", which I have written to help simplify this guide even more. You can reach the tuning descriptions for each section by going to Vehicle Setup, then choosing which part of the car you want to modify, and then go to the section you wish to alter and press Y. This will give you an explanation in both text, which is provided here, and an audio explanation.
WheelsCamber - Increasing the negative camer settings on a rally vehicle allows it to use its tires more efficiently while cornering. This can be an advantage on tarmac stages where there is a lot of cornering involved. If the settings are pushed too high, the vehicle's braking ability will be affected.Drivers can set up the front and rear camber separately to adjust how the vehicle behaved during cornering. This is a good way of subtly affecting the understeer and oversteer characteristics.
Toe Angle - By giving the front wheels a slight toe out angle it is possible to give the vehicle more stability after turning into a corner, however, you will lose some resonsiveness in the steering.A slight toe in angle on the front wheels will increase the steering response but may cause the vehicle to lose stability after turning into the corner. Increasing the rear toe angle of that vehicle will have a more pronounced effect on the vehicle's handling. When adjusting the rear toe angle it is wilse to make small adjustments and then test hte feel of the vehicle to see how it has affected it.
Layman's Terms: The front and rear Camber helps you turn better on tight tarmac roads. It lets you tweak the understeer or oversteer of the car, and changes are minor. Braking ablility is affected if you have too much negative Camber. As for Toe Angle, tweaking the front angle out, you'll come into a turn better, but you may lose steering responsiveness. Tweaking the front angle in increases steering response, but makes you lose stability.
Suspension SpringsStiffness - When competing on tarmac, the stiffest setting possible should be used to keep the body roll of the vehicle to a minimum. By reducing body roll the vehicle is able to change direction quicker, allowing the driver to take corners at higher speeds. On gravel and mud surfaces a softer suspension is used.This allows the suspension to absorb the impacts of the rough road surface preventing damage to the chassis of the vehicle. Softer suspension also allows the vehicle to gain better grip on the loose surfaces. Altering the spring rate affects the pitch of the vehicle. A softer spring rate will let the vehicle pitch forward under braking and back under acceleration.Adjusting the front and rear settings independently will allow you to achieve a better balance to suit your driving style.
Ride Height - Ride height is of great importance in off road racing. When competing on tarmac a low ride height should be used to give the vehicle a low center of gravity and stability as it travels through tight, yet high-speed corners. Chare should be taken not to set the ride height too low, as you run the risk of bottoming out.When heading off road and onto the looser surfaces, the ride height should be raised to allow greater travel in the suspension. This will allow the vehicle to handle uneven road surfaces at speed and manage jumps better.
Layman's Terms: The stiffer your car, the faster you can go on smooth, tight turns on tarmac road. A less stiff car is used on rough road surfaces and gravel to help get better grip and prevents chassis damage. As for Ride Height, the lower you are, the more grip you have on smooth tarmac roads. Keep your ride high on bumpy tracks to prevent damage and manage jumps better.
Suspension DampeningBump - Increasing the absorption of the dampers will make the vehicle feel more rigid, whilst decreasing this value will make the vehicle feel softer. If you set the value of the dampers too high, the vehicle will have a tendency to bounce off the road. Set the value too low and the damper will fail to absorb bumps within the road, causing the bottom of the vehicle to hit the track surface.
Rebound - Rebound settings are also very important as they affect the decompression of the damper. You need to find the softest setting you can get away with to find the sweet spot for the ultimate traction, too soft however and the dampers will cause the vehicle to bounce up and down like a pogo stick.
Fast Bump - Fast bump is needed for stages with lots of jumps with hard landings, your normal bump and rebound settings will contend with most of the track, but for those hard landings, Fast Bump will kick in and save your suspension.You should make the strength of the fast bump higher than your bump setting and make the speed activation setting high enough that the fast bump setting is not being used all the time.This will take a lot of fine tuning, but when its set right your vehicle will handle both light and harsh landings with ease.
Layman's Terms: For Bump, the higher the setting, the better the absorption of bumps. The lower the setting, the smoother the ride. Too much on either, and you could bump off the road or cause the bottom of the vehicle to hit the track. On Rebound, you want a soft setting, but too soft and you'll bounce up and down. As for Fast Bump, it helps deal with hard landings. The strength deals with...the strength, and the activation is to determine when it kicks in. Make it high enough so it isn't used all the time.
TransmissionGearing/Gear Ratios - Adjusting the gear ratios will allow you to help a greater control over how the vehicle accelerates and decelerates.This is especially useful in stages that have open flowing straights, with some tight and twisty sections. The lower gear ratios can be set up with good acceleration in mind, and then the higher gears can be stretched out to allow for higher top speeds. It is important to test the vehicle to check any gear ratio changes that you have made.If you have made the ratios too long the engine will struggle to accelerate through the gears. If the ratios are too short, the engine will race through the gears, reaching only a low top speed and hitting the rev limiter.When creating a varied set-up it is important to check that the gape between the gears are smooth. It can often be a problem balancing the ratios when you are going for mixed low speed acceleration with a high top speed.A separate slider for each gear will allow you to vary the gear ratios. Different vehicles will have differing numbers of gears and individual gear ratios for each gear.There may also be a final drive slider for simple short/long gear range changes.
Layman's Terms: The lower gears are your power gears, giving you more acceleration. The higher gears give you more top speed. Balance between the two is often necessary. For tight and twisty stages, you want more power, so shorten the distance between the lower gears. For open, flowing stages, stretch out the higher gears to achieve the maximum top speed. BUT...if you make the gear ratios too short, you won't maintain a high top speed, and will hit the rev limiter...while stretching the gear ratios out will make your vehicle take longer to reach a high speed, since you have poor acceleration.
BrakesBrake Bias - Setting the brake balance toward the front of the vehicle will give the vehicle a tendency to understeer, however, it will help the vehicle slow down faster on tarmac surfaces when braking in a straight line.Setting the brake balance to the rear of the vehicle will give the vehicle the tendency to oversteer under braking. This can be useful when using left foot braking to drift the vehicle around loose surface corners.
Brake Set - Brake Set allows you to select the components for the Brake system. You have control over the disc size and the pad compound. Getting the correct balance of these will determine how well the brakes work on each surface and how long they will last in each race.Small discs should be used on stages where less braking is required. Smaller brake discs disperse heat slowly, allowing the brakes to retain the correct temperature and hence function at full efficiency. Large discs will need to be used for stages involving lots of braking, as they disperse the heat, reducing the chance of warping and damage.
Layman's Terms: Brake Bias controls which wheels, the front or rear, recieve more brake power. Bias at the front will make you understeer, and bias in the rear will make you oversteer. Using these biases can help you achieve different ways to turn. For Brake Set, small discs are for stages with less braking, and larger discs are for stages with more braking.
DifferentialsCentral Diff - Also known as the drive bias, the central differential allows the driver to adjust how much of the engine's power is being delivered to the front or rear wheels of their four wheel drive vehicle.Adjusting the differential towards the front will give the vehicle a tendence to understeer, behaving more like a front wheel drive vehicle when the throttle is being applied mid-turn. Adjusting the differential towards the rear will cause the vehicle to over steer and behave more like a rear wheel drive vehicle when accelerating and turning.
Limited Slip Diffs - Adjustments to the limited slip differentials will dramatically afect the vehicle's handling characteristics. In four wheel drive vehicles you can adjust the front and read differentials independently.
By increasing the strength of the differential under acceleration, the traction will be increased when exiting corners. This is because the differential will prevent the inside wheel from spinning. Increasing the strength of the differential under deceleration will make the vehicle more stable under braking and give the vehicle a tendency to understeer.It is worth noting that a strong deceleration setting will make the vehicle difficult to steer and is recommended only for drivers with a late braking driving style.
Layman's Terms: Shifting the Central Differential to the front makes you understeer and gives you a FWD feel, and shifting to the rear makes you oversteer and gives you a RWD vibe. As for the Limited Slip Diffs, stronger diffs in acceleration gives you more traction when exiting corners, and increasing the strength in deceleration makes the vehicle more stable while braking, but decreases the amount you can steer.
DownforceDownforce Strength - High downforce settings will push the vehicle down onto the road at high speeds. This extra grip allows the driver to take corners faster. High downforce settings will also limit the vehicle's top speed due to the added wind resistance.On fast open stages it can be advantageous to reduce the downforce so that the vehicle is able to obtain a higher speed, however, this will reduce the cornering speeds as the vehicle will become more unstable.
Layman's Terms: More downforce lets you take corners faster, but makes you have less top speed. Less downforce lets the vehicle obtain a high speed, but doesn't let it take the corners as well.
Anti-rollAnti-roll Bar - Sometimes known as stabilizers, the anti-roll bars are an additional way of improving the responsiveness of the vehicle when the taking corners. A stiff anti-roll bar setting will suppress the body roll of the vehicle and allow the momentum to shift quickly.A soft anti-roll bar will allow more body roll and prevent the vehicle from bouncing on a stiff suspension set up.Setting a stiffer rear anti-roll bar setting than you have at the front is a good way of inducing oversteer when cornering.
Layman's Terms: The harder the Anti-roll Bar, the tighter you can turn. The softer they are, the more it prevents the vehicle from bouncing on a stiff suspension set up. If you're harder in the rear than in the front, you get oversteer when cornering.