Now includes tuning tips for Forza Horizon 5 and earlier Forza titles.
Tuning in Forza Horizon 5 and earlier games makes the driving experience that much better. Imagine making your own well-balanced tunes. No more relying on locked tunes with parts you don’t want. No more searching the Internet for open source tunes that match the parts you do want.
This guide will provide you with a better understanding of the tuning menu options, and a way to make tunes with little, if any, math. This is also great background information if you are using ForzaTune tuning calculator apps.
And with that, let’s jump in!
Table of Contents
Tires: How to Choose the Best Pressure and Compound
Each tire touches the road through a relatively small area. We call them contact patches. These contact patches transmit all the force from steering, accelerating, and braking.
Tires need the right amount of pressure to give this contact patch a good shape. They also need to be warm enough to bite into the road surface. Extremes in either case mean less grip.
Picking the Right Compounds
Your tire compound choice will depend on how hard the car is driven and whether your build needs more speed or more grip. A tight, technical track will create more friction and heat in the tires. You will likely want a semi-slick or race compound to maintain extra grip.
A track with more high-speed straights can get away with street or sport compounds because the tires will stay cooler. Those builds will do better to use the performance index (PI) for power upgrades or weight reduction.
In Forza Horizon, things are simple and most tire compounds used on the street operate fine between 170 and 250 °F, or 75-120 °C. The different compounds simply add more grip.
Tires, Misc. Telemetry. To view tire temperature and pressure in Motorsport, press ‘down’ on the directional pad and then, using the right d-pad button, scroll across to the ‘Tires, Misc’ view.
You need to be more strategic in Forza Motorsport, and check tire temperatures using the Heat or Tires, Misc. screens on the telemetry. Stock or street compounds work well up to 170 °F (75 °C), sport is useful from 160 to 200 °F (70-95 °C), and race compounds are best between 170 and 220 °F (75-105 °C).
Compounds also wear at different rates, but we’ll save that for another article since it is less common to enable tire wear in shorter Forza races.
How to Find the Best Tire Pressure for Forza
Follow these steps to figure out the best tire pressure for your car when driving on the street or track:
- Set your tires to a “cold” pressure between 27 and 30 PSI (1.90-2.07 Bar).
- Drive a minute or two to warm up your tires.
- Pull up telemetry and go to the Tires, Misc. screen. Follow these steps to enable telemetry in FH5 or FH4.
- Check that the warm tire pressure is between 32 and 34 PSI (2.20-2.35 Bar).
- If front tire pressure is too high or low, move the tire pressure setting in the tuning menu down or up.
- Repeat step 4 for the rear tires or do it simultaneously.
- Re-check tires after all other suspension adjustments.
Higher tire pressure will make cars more responsive, while lower pressures are more forgiving. You will have similar front and rear tire pressures for most RWD and AWD cars.
Tuning tip: in Forza Horizon tire temperatures can be a bit more variable. A straight road, changing weather, or splash through some water can cool tires down quickly. Your car may handle less consistently as a result. Be sure to pick a circuit or make your own testing path to get a reliable reading.
Summary of Tire Tuning
Use tire temperature telemetry to choose the right tire compound for the car and type of driving. Make sure your tires are between 32 and 34 PSI (2.20-2.35 Bar) when driving. The ForzaTune app will typically recommend the proper tire pressure front and rear based on the game, and the Pro version will also help you with other tuning modes like drifting, drag and rally.
Camber: Why and How to Make Adjustments
Camber is the angle of the tire looking at the front of the car. When the tops of the tires are closer together, we call that negative camber. Bring the bottom of the tires closer together and you have positive camber.
Why Tune Camber?
Camber is almost always negative or close to zero, and makes a surprising difference in how your cars handle in Forza Horizon or Forza Motorsport.
Imagine taking a turn and the weight rolling onto the outside edge of the tires. Negative camber cancels out this effect, allowing the tires to use more of the contact patch and have more grip.
Why not run maximum camber? You still want grip when driving straight. Excessive camber will put too much weight on the inside edge of the tire. This reduces acceleration off the line and increases braking distance.
How to Tune Camber
We will use the telemetry screen again. Look at the “Heat” view for the outside tires during a turn. For example, if you turn right, then you will check the driver’s side tires.
Detailed Tire Temperature Information. On the “Heat” telemetry view you can see the temperature of the tires in more detail. Each has 3 areas: inner, middle, and outer. These should be close in value as you leave a turn.
Here is a simple process to tune camber in Forza Motorsport or Horizon:
- Use the default camber or start with -1.0 to -1.5 degrees.
- Warm up the tires and take a series of turns.
- See if the tires heat evenly as you leave the turn.
- If the tire is noticeably hotter on the outside edge, make the camber more negative.
- If the inside of the tires are much hotter, move the camber slider closer to zero.
- If the car requires more than -2.0 degrees of camber in the front, consider increasing caster angle, which we will discuss in the next section.
- Re-check camber after other suspension changes as outlined in the tuning checklist.
Tuning tip: get your reading as you are leaving the turn and not in the middle. This will help you avoid setting camber too negative.
Additional Notes on Camber Tuning in Forza
On the straights, the inside edges of your tires will be warmer, which is fine. Even when using a tuning calculator like ForzaTune Pro that gives a specific camber, it’s worth double-checking the tire temperature for your favorite vehicles.
Camber Tuning Summary
If tire pressure helps us maximize the contact patch, then camber allows us to keep that contact patch weighted evenly as we turn. We want to find a camber angle that maximizes cornering grip, that also maintains straight-line handling.
The ForzaTune app uses default camber similar to what we show here, and the Pro version uses vehicle data to make a more accurate base setting. This cuts down on trial and error. It’s always good to know how to check this manually though.
Toe and Caster: Why You Can Usually Ignore These
Forza Motorsport and Forza Horizon give you several alignment settings. It’s important to understand them all, but there are two that are less likely to require attention. These are toe and caster.
What is Toe?
Toe is the angle of the tires if you looked down from the sky. If the tires point in, we call that toe in. If the tires point out, we call it toe out. Easy enough!
We adjust toe angle in small amounts. We’re talking tenths of a degree.
Effects of Toe on Front Tires
During a turn, the inside tire travels on a tighter radius.
Having toe out allows the inside tire to turn more than the outside. This helps the car turn-in sharply, but it quickly loses the effect as the weight transfers to the left tire. Toe is only a factor in the first or last moment of a turn.
As you would expect, toe in on the front tires will make the car less willing to start that turn. This is not helpful on the front, but can be for the rear.
Effects of Toe on Rear Tires
A tiny amount of toe in on the rear (0.1 or 0.2 degrees) will make that inside tire resist turning. This reduces oversteer–or likeliness of spinning out–when entering or exiting a turn. The most likely scenario for any rear toe in would be a high-powered RWD vehicle.
Avoid Toe If Possible
Toe causes tires to pull in different directions in a variety of other situations. We call this tire scrub, and it can increase wear and reduce top speed.
With proper spring, damper, anti-roll bar and differential settings, you can keep front and rear toe at 0 degrees.
Tuning Tip: Toe settings cause less predictable results in Forza Horizon 5. It is best to apply the above advice to Forza Motorsport only and leave toe settings at zero in Forza Horizon.
How to Set Toe on Your Tune
- Set front and rear toe to 0 degrees if they are not already.
- Tune the rest of the car as outlined in this guide or using ForzaTune.
- If the car is front-wheel drive and no other settings fix a hesitation at turn in, add 0.1 degrees of toe out in the front.
- If the car is rear-wheel drive and no other settings remove the bit of oversteer or snappiness when changing throttle in a turn, consider adding 0.1 degrees of toe in to the rear.
Toe settings allow you to have fine control over those first and final moments of a turn. But with Forza Motorsport, and definitely with Forza Horizon, you will probably leave toe at zero. ForzaTune recommends the same and only has a few situations cases where it will recommend non-zero values, which I won’t bore you with here.
What is Caster?
Caster refers to the angle between ‘true’ vertical and the suspension strut assembly. You will only see it on the front tires.
Caster is always positive in games like Forza. Positive caster encourages the wheels to return to center if you were to remove your hands from the steering wheel. The greater the angle, the more stable the car is on the straights.
Why Not Run Max Caster?
Caster has a few side effects. It adds more steering effort and creates more dynamic camber during a turn. In a simulator, the steering effort is not as noticeable. Too much camber can be a problem, as mentioned in the camber section.
Set the caster angle to 5.5 +/- 0.5 degrees.
If the car weaves during long straights and requires constant correction, then increase the angle by a few tenths.
Tuning Tip: Forza Horizon 5 has a new tire model that seems to be more sensitive to caster than previous games. Values above 6.0 degrees make the car a bit too snappy during turn in.
How to Test and Tune Caster
- Set caster to 5.5 degrees, or the default value if it is higher. If using the ForzaTune tuning calculator, it will recommend a starting point.
- Tune the rest of the car as outlined in this guide or using the ForzaTune tuning app.
- If the car feels too erratic on the straights, increase the angle by one or two tenths and re-test.
- If the car snaps on turn in, decrease the angle to avoid excessive front camber.
Caster is a fairly low maintenance setting. In almost all cases, a value between 5.0 and 6.0 will work fine. With our contact patches ready, it is time to consider the different ways we control weight transfer. Keep reading to get a better understanding of springs, anti-roll bars, and dampers.
Springs: What They Really Do and How to Find the Right Balance
Adjusting springs and ride height is a major part of tuning in Forza Horizon 5 or Forza Motorsport. A good suspension setup keeps each tire in contact with the track surface for as much time as possible. Let’s learn what the springs do, and some rules of thumb for setting them correctly.
Understanding Spring Rates
Springs are the primary way your car adapts to bumps in the road. Each spring has a “spring rate” which tells us how easy it is to compress.
The spring rate has units of force over distance. In Forza, you may see units like Newtons per meter (N/m), kilograms of force per millimeter (kgf/mm), or pounds of force per inch (lb/in).
Are Softer Springs Always Better?
A softer spring rate means we need less force to compress that spring. When we go over a bump or onto a steep curb, the springs compress easier and keep the tires in contact with the road instead of launching it into the air.
But softer spring rates may be more likely to bottom out, which means the springs compress completely.
Suspension Telemetry on FH5. The dark pink bar indicates how much the suspension had to move up to absorb a bump. In this example the suspension is nearly fully compressed and is likely to bottom out.
A bottomed-out suspension connects the body of the car directly to the wheels. It’s like going from a super-soft spring rate to an infinitely high one.
Sudden changes like that are not good when we’re trying to maintain control and drive smoothly.
What’s the Problem with Stiffer Springs?
A higher spring rate means more force is required to compress the spring. Setting springs high would solve the bottoming out problem, but likely introduce another one. Cars with stiffer springs are more likely to skip across the smaller bumps.
If the tire loses contact with the road–even for a fraction of a second–you are losing the ability to steer or control the car.
We want soft springs that will avoid bottoming out, but that doesn’t mean we will end up with a soft setup. We also have to consider ride height, responsiveness and track surface.
Tips for Tuning Springs
- Heavier vehicles require stiffer springs to support them.
- Springs usually match the balance of the car. More weight up front means stiffer front springs and so on.
- Lowering the ride height provides better center of gravity and handling but means less space for the spring to compress, and higher chances of bottoming out.
Understanding Oversteer and Understeer
Oversteer happens when the rear of the car loses grip before the front. The back end will spin and this is most common in the middle or end of a turn.
Understeer happens when the front end loses grip first and the car wants to push off the track. It is more common at the start or during the middle of a turn.
The easiest way to remember oversteer or understeer is to think of rotation. Is the car rotating over or more than you expected? Or is the car rotating under or less than you expected?
Oversteer and understeer largely depend on how we set the front and rear spring rates in relation to each other. Whichever end is relatively stiffer will lose grip before the other.
How to Tune Spring Rates Without Doing the Math
Tuning springs will go hand-in-hand with anti-roll bars and dampers. A tuning calculator like ForzaTune Pro will dramatically cut down on the trial and error. But here’s a checklist to get you started:
- Make sure your car has an adjustable suspension installed by default, or install a race suspension. In Horizon, do not install a rally suspension by accident (a common mistake on cars like the 911 GT3).
- Start with a ride height that is low if you plan to drive on a smooth track or higher if the road surface will have more bumps and dips.
- Note how much your upgrades changed the weight distribution from stock.
- If front weight percentage is now lower, decrease front spring rates, and add the difference to the rear spring rates. Do the opposite if front weight increased.
- Shift 15 lb/in (4 kgf/mm) for every 1 percent change in weight distribution. For example, if front is lighter by 2% subtract 30 lb/in from front springs and add it to the rear springs.
- Tune the rest of the car as described below.
- Check that the suspension telemetry bar graphs do not reach maximum when driving. Increase ride height if they do, and increase spring rates if ride height is already at maximum.
- Refer to the tuning checklist for further adjustments.
Tuning springs is a major part of Forza Horizon and Motorsport. And many times, the game will automatically adjust them up or down based on weight changes. But Forza will not rebalance them when weight moves front to rear, and will not check ride height for you. Luckily, you now know what to look for and can always use ForzaTune to figure out the best values quickly.
One More Thing About Springs
Sometimes we don’t want to use springs to tune out oversteer or understeer. It might make the ride too soft and lead to excessive diving or squatting. Diving is when the front springs are too soft and the car leans too far forward when braking. Squatting is when the rear springs are too soft and the car’s weight shifts too far back when accelerating. We can get around this by using anti-roll bars.
Anti-Roll Bars: An Easy Way to Tune Mid-Corner Handling
In real life, we replace parts or adjust connection points to change anti-roll bars (ARBs). Forza Horizon and Motorsport make it much easier. Here you will learn how ARBs work in theory, and an easy way to set a base tune for your build.
What Do Anti-Roll Bars Do?
In a corner, the vehicle will roll because of the flex in the springs. The weight transfer causes the springs on the outside wheel to compress, and the springs on the inside wheels to extend.
Anti-roll bars – also known as ARBs or anti-sway bars – connect the inside and outside wheels together, forcing the inside wheel to mimic the movements of the outside wheel.
As the ARBs force the two sides to mimic each other, the car stays “flatter” in the turn.
How Anti-Roll Bars Work
You can think of ARBs as adding spring stiffness, but only when turning. Instead of compressing like a coil spring, ARBs are torsional springs. They have some “twist” or give to them.
A stiffer bar will force the inside and outside wheels to mimic each other more closely, which will lead to less body roll. The opposite is also true. A softer bar means the left and right springs can move more independently, and allow more body roll.
ARBs mostly affect mid-corner, and have no effect on straight-line driving.
How to Tune Anti-Roll Bars in Forza Horizon or Motorsport
Anti-roll bar values are tough to calculate exactly without more involved math. ForzaTune or ForzaTune Pro can make the process much faster. If you prefer to tune by hand, here are ways to get close.
- Upgrade the vehicle to include front and rear race anti-roll bars if they are not adjustable by default.
- Note how much lighter the car is from stock (ex. -200 lbs or -90 kg) and how much the front weight percentage has changed (ex. 54% to 52%).
- For every 100 lb or 45 kg removed from the car, reduce ARBs by 1.0.
- For every percent removed from the front weight distribution, remove 0.5 from the front and add 0.5 to the rear.
- Continue with damper tuning.
- Run through the tuning checklist to fine-tune your values for oversteer or understeer.
Tips for Tuning Anti-Roll Bars
ARBs have a noticeable and immediate effect when tuning in Forza. They should be your first strategy for tuning oversteer and understeer.
- If you need to reduce understeer, reduce front ARB stiffness.
- If you need to reduce oversteer, reduce rear ARB stiffness.
- Do not fix a problem on one end by making adjustments at the other end
These suggestions follow the rule of adjusting the end with the problem. For example, do not reduce oversteer–which is a problem with the rear of a car–by increasing front ARB stiffness.
ARBs are like springs that only come into play when the car’s weight shifts side-to-side. ForzaTune Pro will make quick work of finding the ideal values, and the above steps will help you find those by hand.
Dampers: Keep Your Car Fast and Predictable
Forza Horizon and Motorsport give us the ability to tune a simplified version of dampers using rebound and bump adjustments. Here you’ll learn what those terms mean and what effects damper tuning has on car handling.
If springs and ARBs control how far the suspension moves, then dampers control how quickly the suspension moves. Properly tuned dampers make it much more fun to drive in Forza. They will keep the car predictable as it brakes, leans into a turn and then transitions to throttle on exit.
In the real world, dampers are a tube with fluid and an internal plunger that moves through that fluid, creating resistance. Stiff dampers resist changes in speed like moving your hand through honey. Soft dampers would be like moving your hand through water.
The honey is more “viscous” and slows things down considerably.
If we connect the damper in line with our springs, we can control the movement over bumps much better. With soft or no damping, a car keeps bounces uncontrollably on its springs.
It’s actually pretty fun to try it yourself. Take one of your tunes and turn all damping values to 1.0 and see what happens after hitting some bumps. For bonus points, increase spring rates for that extra kick.
Bump vs. Rebound
As you have probably seen in the Forza tuning menu, we can tune damper stiffness in two directions. The first is during suspension compression, which is called bump damping. The second is during extension, which is called rebound damping.
Bump damping controls how fast the wheel moves into the wheel well. Rebound damping controls how fast the wheel can push back into the road.
One way to remember the difference is to visualize how the suspension compresses when hitting a bump.
Tips for Damper Tuning
How does the damping stiffness affect the handling of the car and what are some important points to know?
- Damping should match changes to the springs. Stiffer springs require stiffer dampers.
- More damping works best if the track is smooth, but not when the surface is bumpy or irregular.
- If the dampers are too soft for the car and track, it will make the car feel unstable and oscillate more than it should as you drive around the track.
- Forza does not adjust dampers automatically when the vehicle’s weight changes.
- The bump setting will usually be less than (around two-thirds) the rebound setting.
- Soften the front damping settings to reduce understeer.
- Soften the rear damping settings to reduce oversteer or lift-off throttle issues.
How to Tune Dampers in Forza
Dampers need to match springs and anti-roll bars for best results. This is another part of tuning handled automatically by ForzaTune Pro. If you want to tune by hand using the default settings as a base tune, here is an alternative approach:
- Note how much lighter or heavier your vehicle is after upgrades and how the weight distribution changed.
- For every 100 lbs (45 kg) of weight reduction, reduce default rebound values by 0.3 and default bump values by 0.2. Add this same amount of damping for weight increases.
- For every percent of front weight reduced, subtract 0.2 from front rebound and damping and add 0.2 to rear values. Do the opposite if upgrades increase the front weight percentage (common with conversions).
- Finish tuning brakes, aero and differentials.
- Refer to the tuning checklist to fine-tune your damping and change oversteer or understeer at different parts of the turn.
This is a simplified approach to the math but makes it a lot easier to do by hand. As an example, if a car starts at 3000 lbs and 52% front weight and ends up at 2800 lbs and 51% front weight with upgrades, we would make the following changes:
- Note that the car is 200 lbs lighter and has a balance shift of 1% towards the rear.
- Reduce both default rebound values by 0.6, which is 0.3 for every 100 lbs removed from the car.
- Reduce both default bump values by 0.4, which is 0.2 for every 100 lbs removed from the car.
- Subtract 0.2 from front rebound and front bump, and add 0.2 to rear rebound and rear bump to adjust for balance.
Again, damper tuning is a great reason to use a tuning calculator, especially as you make further adjustments to dial in that tune. Learn more about ForzaTune Pro here.
Dampers give you better control of the car as weight is shifting. They help the suspension come to rest faster than if you had only springs. But too much damping slows the car’s reaction to bumps, sending you sliding across the road.
With an understanding of springs, anti-roll bars and dampers, you have everything necessary to control weight transfer. Next, we look at enhancing grip through aero, brakes and differentials.
Aero: When the Upgrade is Worth the Look
Forza allows aerodynamic upgrades that unlock downforce adjustments. It’s one way you can increase grip as you drive.
How Aero Works
When travelling at high speeds, we use the air flowing over the car to push down on the vehicle. It’s like adding weight to the tires. More weight translates to more grip.
There are two factors that determine this extra weight or downforce. The angle of the wing and the vehicle speed.
Adjusting the aero sliders in Forza is our way of increasing or decreasing the wing angle. Regardless of the setting, you need a good amount of speed to generate downforce. As a result, handling improvements only happen at higher speeds.
There are some downsides to aero. First, higher downforce settings create more aerodynamic drag, which reduces top speed. Second, the fully adjustable aero upgrades in Forza don’t always blend well with the original styling of the vehicle. But that’s more of a personal choice.
When Aero Matters
Let’s talk about when to use aerodynamic downforce.
Aero settings depend on the track. We would love to increase grip on short winding tracks, but if we can’t get the car fast enough to benefit from the wing’s effects, is the aero tuning worth it? Probably not.
Then we might think aero is more useful for longer tracks. But tracks with long straights benefit from reduced downforce to maximise top speed…
Aero matters most on tracks that have one or more high-speed corners. If those longer, sweeping corners lead onto a straight, then that’s even better.
Using aero on those higher speed corners will let you build exit speed much better than a car with less aero.
How to Tune Aero in Forza
ForzaTune’s philosophy is not to treat aerodynamic settings as an input to the tuning process. It is a way to adjust or enhance the rest of your tune. Here are some steps to help you quickly settle on some values:
- Decide if you need fully adjustable aero upgrades based on the type of driving and preference for style.
- If you decide to upgrade, it is best to do both the front and rear to avoid creating imbalances at speed. Start with the front and rear slider positions together. We care more about relative position than the number values.
- Move both sliders somewhere between the midpoint and 3/4 of maximum depending on how much top speed you will sacrifice. The simulation results can help here.
- Finish the rest of your tune, including differentials and braking.
- Use the tune checklist to make final adjustments
Tips for Fine-Tuning Aero in Forza
You want to follow the same ideas we talked about in the previous tuning guides: make adjustments to whichever end is having a problem.
If you notice the rear of the car slides out at the end of a higher speed corner, then try increasing rear downforce a bit while leaving the front alone.
If you find the car sliding off of the road in a higher speed corner, then try increasing front aero.
Aerodynamics is another way to tune the balance of the car during a specific situation. It only helps at higher speeds, and can work well for long-winding turns like Circuit de Spa-Francorchamps or open stretches in Forza Horizon. But if you are going for maximum speed or doing a highway run, consider removing aero or turning front and rear to the minimum setting.
Brakes: How to Tune Balance and Pressure
The race brake upgrade in Forza Horizon and Forza Motorsport gives you better control over how the car decelerates. We will talk about how brake balance, pressure and the type of braking situations determine your tuning approach.
Brake Balance Overview
Brake balance refers to the split between front and rear brake force. The brake balance setting in Forza is a slider that goes from 100% to 0% with 50% being the default value. 100% represents front braking only and 0% represents rear braking only.
Tuning Tip: brake balance is backwards in Forza Horizon series because of an unresolved bug. If you want to move brake balance towards the front, then move the slider to the right.
Adjusting brake balance will depend on your style of braking – for example, if you use trail braking or not. You will typically see a forward bias since most of the braking power will come from the front wheels.
Tuning Brake Balance for Trail-Braking
If you trail-brake–which is trailing off the brakes as you enter a corner–and suffer from turn-in understeer, then send brake balance towards the rear.
Likewise, if you turn-in and the rear slides, send brake balance towards the front.
Tuning Brake Balance for Straight-Line Braking
If your front wheels lock approaching a turn and cause you to miss your turn-in point, send brake balance a little rearwards. If the rears lock up, send the balance forwards.
While you want to avoid locking up the brakes, if it happens, the front and rear brakes should lock together.
Brake Pressure Overview
Pressure adjustments depend on your experience level and preferences.
If you prefer to squeeze the trigger through the full range, and find that your brakes consistently lock up, you can reduce the pressure setting.
If you only pull the trigger half-way and the brakes are not effective enough, increase the pressure setting.
If you want to ensure you have the full range of braking force then target a pressure setting where tire lock happens in the last 10-15% of trigger or pedal movement. This gives you a higher “resolution.”
Tuning Brakes in Forza
- Install the race brake upgrade.
- Set the brake balance to 52-53% in Motorsport (48-47% in Horizon).
- Set brake pressure to 100%
- Finish the rest of your tuning, including differentials.
- If the brakes cause rear tires to lock up more, then shift brake balance 1% towards the front (left in Motorsport, right in Horizon). And vice versa if front tires lock up more than the rears.
- If both tires lock up during braking more times than not, consider adjusting braking strategy to “roll onto” the brakes, or reduce brake pressure by 5-10%.
- Repeat steps 5 and 6 as needed.
Brake balance allows you to control and improve grip as you approach a turn–especially if you use trail-braking techniques. Getting a proper braking balance and pressure is a relatively quick process, and will help you be more consistent and faster in your driving.
Differentials: Learn How to Put More Power to the Ground
Not sure where to start on that last Forza tuning screen? Differential tuning is an often misunderstood part of tuning in Forza. We will cover the race differential upgrade, which allows you to adjust both acceleration and deceleration behavior. Forza Horizon 5 introduces more options for fully adjustable differentials, but the same tuning tips apply.
Fully adjustable differentials give us the chance to improve grip while accelerating, braking and turning.
Imagine an axle as you drive around a turn. The outside wheel will trace a larger circle than the inside wheel.
If the outside wheel is traveling farther in the same amount of time, then it must travel faster than the inside wheel.
The outside wheel would skid if both wheels were driven at the same rate. A differential is a system of gears that allows the inside and outside wheels to spin at different rates.
Open vs. Locked Differentials
We say a differential, or diff, is open when it allows both wheels to spin independently. This would be the 0% setting in the Forza tuning menu. A locked diff forces both wheels to spin together constantly. This is 100% on the tuning menu.
Technically, an open diff will give you the most traction through a turn, but ONLY when moving at a constant speed. Try accelerating out of that turn with an open diff and one wheel is going to spin easily.
The Problem With Open Differentials
The problem with a completely open differential is that it sends power to whichever wheel spins the easiest.
When weight transfers to the outside tire during a turn, that means the inside tire will have less grip.
Hit the throttle and the inside tire will spin, and no power goes to the outside tire. It’s like all of our acceleration is “leaking” out of that wheel.
A limited slip differential (LSD) solves this problem. An LSD allows the wheels to spin independently up to a point and keeps our ability to accelerate out of a turn.
You’ll have a differential for each set of drive wheels. That means one diff in the front for front-wheel drive or one in the rear for rear-wheel drive.
All wheel drive cars have a front, rear and center differential, which controls front to rear torque split.
How to Tune Differentials in Forza
Tuning differentials is easy to if we remember these two points:
- Higher differential settings mean more locking of the inside and outside wheels.
- Lower differential settings mean less lock or more freedom to rotate at different speeds.
Tuning Tip: Having trouble remembering which end of the slider is open? When you see 0%, remember that it looks like the letter “O”, for open.
With the fully adjustable differentials, you can choose acceleration and deceleration values, though default values can be a good place to start.
Keep in mind that acceleration settings only apply when on the throttle. Deceleration settings apply only when off the throttle.
The following tuning guides are for street or track use, the fine-tuning process applies to off-road too.
Tuning Differentials for Rear-Wheel Drive
- Install a race or other adjustable differential.
- Set acceleration between 50-60% in Forza Motorsport and 25-45% in Forza Horizon if it’s not in that range by default. Err towards the lower end if you have more power and torque.
- Set deceleration values between 20-40% in Forza Motorsport and 30-45% in Forza Horizon if it’s not in that range by default. If you prefer more understeer at turn in, err towards the higher end of the range.
- If you want less oversteer on turn exit, decrease acceleration in 2-3% increments.
- If you want less oversteer on turn entry, increase deceleration in 2-3% increments.
Tuning Differentials for Front-Wheel Drive
- Install a race or other adjustable differential.
- Set acceleration between 20-30% in Forza Motorsport and 15-25% in Forza Horizon. Use the default value or pick a value closer to the lower end if the vehicle has more power.
- Set deceleration between 0-10% in Forza Motorsport and 10-20% in Forza Horizon if default values are not within range. If you prefer more understeer at turn in, err towards the higher end of the range.
- If you want more understeer on turn exit, increase acceleration in 2-3% increments.
- If you want more understeer on turn entry, increase deceleration in 1% increments.
Tuning Differentials for All-Wheel Drive
- Install a race or other adjustable differential.
- Use the above FWD and RWD values as a starting point, or use default values provided by the upgrade.
- Set center split in the 60-70% range.
- Adjust turn entry balance using front and rear deceleration settings.
- Adjust turn exit balance using front and rear acceleration settings.
- For mid-corner balance, increase center split for more oversteer.
Following this guide will give you a solid base tune to refine further. You can run through the tuning checklist to work out any issues.
One thing you may have noticed is that many settings affect the balance and handling. It’s hard to remember which to try first, and time-consuming to make slight adjustments to all of them. This is where the ForzaTune tuning apps shine. They recalculate all settings instantly whenever you create a new tune, or want to make adjustments.
You can download the free version of ForzaTune here, and learn about the ForzaTune Pro version here.
Whether you choose to tune by hand, or use ForzaTune, you should now understand what each setting is doing. Bookmark this page and feel free to refer to it whenever you want to make a new tune.