Horizon 4 Tuning Guide

Part 1 - Horizon Tuning Basics

Understanding Car Types and Body Types

When it comes to tuning in Horizon the most important aspect you need to understand is the concept of car types and body types.

Car types provide a general classification of all cars in Forza and group several body types. Each car type needs a distinctive way to be setup in terms of tuning.

Generally Horizon distinguishes between road and off-road cars.

 

The following road car types exist in Forza Horizon:

  • Utility Car(vans, SUVs)

  • Street Car(sedans, wagons, muscle cars, compact cars)

  • Sports Cars (sports cars, GT sports cars)

  • High Performance Cars (super cars, hyper cars)

  • Race Cars (GT race cars)

  • Race Trucks

  • Prototype Race Cars (LMP cars)

  • Open Wheel Street Cars 

  • Open Wheel Sports Cars

  • Open Wheel Race Cars (classic GP race cars)

 

The following off-road car types exist in Forza Horizon:Ra

  • Rally Cars 

  • Off-road Cars (jeeps)

  • Off-road Trucks (pickups)

  • Open Wheel Off-road Cars (buggies)

  • Off-road Race Trucks (trophy trucks)

Now what is a body type? A body type defines the basic characteristics of a car such as suspension geometry and chassis and suspension stiffness. Forza does not simulate cars on an individual car level but on body type level. That means all cars that share the same body type are running on the same virtual representation of the car.

An example would be a classic American muscle car that  features a very conservative suspension geometry combined with a soft chassis and suspension setup that gives you that unique "boat like" handling on roads.

 

In contrast modern F1 race cars features a unique open-wheel suspension geometry along with a much stiffer chassis and suspension characteristics that is suitable for high-speed racing on ultra-flat race tracks.

Body types are similar to the concept of divisions that group similar cars to achieve more close racing but they are not identical. Sometimes divisions contain cars of different body types or cars of a certain body type are spread across several divisions. Think of divisions more of an organizational grouping of cars whereas body types define the physical (or simulated) taxonomy of all cars in Forza.

To further diversify body types with regard to the period of time a car has been built Forza uses an era system:

  • Modern: cars built 1995/96 or later

  • Early Modern: cars built 1981-1994/95

  • Vintage: cars built 1960-1980

  • Early Vintage: cars built 1940-1959

  • Pre-War: cars built before 1940

That means the correct body type of a 1979 Chevrolet Camaro is a "Vintage Muscle Car" whereas a 1987 Pontiac Firebird TransAm is an "Early Modern Muscle Car". 

Now how do car types and body types affect tuning? Generally speaking older cars require a stiffer chassis and suspension tuning and a more conservative alignment and differential tuning than modern cars and race cars require softer chassis and suspension tuning and a more aggressive alignment and differential tuning than production cars.

Open Wheel race cars and Prototype race cars however don't follow this pattern because they are exposed to extreme forces while cornering so they need very stiff chassis and damping setup to handle those forces.

The following table gives an overview how car type and era affect the different tuning areas:

Car Type                             Camber / Caster              ARBs Springs1                Rebound / Bump              Diff Accel / Decel

Utility Car                                     Medium                      Medium / High                    Medium / Low                     Medium / Low

Street Car                                     Medium                      Medium / High                    Medium / Low                     Medium / Low

Sports Car                                    Medium                      Medium / High                    Medium / Low                     Medium / Low

High Performance Car              Medium                          Low  / High                       Medium / Low                     Medium / Low

Race Car                                 Medium / Low                    Low  / High                        Medium / Low                     Medium / Low

Race Truck                              Medium / Low                    Low  / High                       Medium / Low                     Medium / Low

Prototype Race Car                 Low / High                      High / Medium                   Medium / Low                         High / Low

Open Wheel Race Car             Low / High                        High / Low                                 High                                       Low

Open Wheel Sports Car       Medium / High                 Medium / Low                         Medium                                    Low

Open Wheel Street Car        Medium / High                 Medium / Low                             Low                                        Low

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Rally Car                                        Medium                      Medium / High                    Medium / Low                     Medium / Low

Off-road Car                                 Medium                      Medium / High                    Medium / Low                              Low

Off-road Truck                              Medium                      Medium / High                         Medium                                   Low

Open Wheel Off-road Car    Medium / High                 Medium / Low                          Medium                                   Low

Off-road Race Truck                     Medium                      Medium / High                         Medium                                   Low

Era                                        Camber / Caster              ARBs Springs1              Rebound / Bump              Diff Accel / Decel

Modern                                  Higher / Lower                        Lower                            Higher / Lower                    Higher / Lower

Early Modern                             ^           |                                   |                                     ^           |                               ^            |

Vintage                                        |           |                                   |                                    |            |                              |             |

Early Vintage                              |           V                                   V                                    |            V                              |             V

Pre-War                                  Lower / Higher                        Higher                           Lower / Higher                    Lower / Higher

1 In relation to car weight

Mind you these principles only give general guidance and cannot directly be translated to specific values.  

For a complete list of cars along with their respective car and body types please refer to Appendix A - Car List.

Understanding Drive Types

Another fundamental thing when it comes to tuning is to understand the different drive types and how they effect tuning.

A cars drive type is determined by two factors: engine position and drivetrain. While engine position is a fixed property of each car that cannot be changed, the stock drivetrain can often be swapped and thus changes the cars drive type.

There are three different engine layouts possible:

  • Front Engine: this is the most common engine layout where. the engine is located at the front of the car

  • Mid Engine: this engine layout moves the engine between the driver and the rear wheels and is often used for race cars and high performance cars because it moves the center of mass more towards the middle of the car which in turn offers better rotating capabilities

  • Rear Engine: this is the least used engine layout where the engine is located directly above the rear wheels, it offers the best traction for rear wheel drives because of the added weight on the rear axle but has the worst cornering capabilities due to most of the weight is located on the rear of the car making it prone to understeer

Likewise there are three different drivetrains:

  • RWD: rear wheel drivetrains are the most common used drivetrains where the rear wheels are the driven wheels and the front wheels are the steering wheels, in combination with front engine layout is this the most common drive type

  • FWD: front wheel drivetrains are common on many compact and small engine cars as they allow for a more compact vehicle when used in combination with a front engine layout, in front wheel drivetrains the front wheels are used for both acceleration and steering

  • AWD: all wheel drivetrains are common on most off-road cars and SUVs as they offer improved off-road handling, in all wheel drives all wheels accelerate and the front wheels are also used for steering

The combination of engine position and drivetrain leads to following common drive types:

  • FR: front engine rear wheel drive is the most common drive type as it offers the most balanced layout with the engine in the front and the drivetrain on the rear

  • FF: front engine front wheel drive is a common drive type for compact cars as it allows to put both engine and drivetrain on the front of the car making it the most compact and lightest drive type

  • MR: mid engine rear wheel drive is often used in race cars and high performance cars as the center of mass is more in the middle if the car for improved turning

  • RR: rear engine rear drive is rarely used for some race cars and high performance cars as it offers best traction for improved acceleration

  • MF: mid engine front wheel drive is rarely used on some compact sports or rally cars

  • F4D: front engine four wheel drive is the most common drive type for off-road cars and SUVs

  • M4D: mid engine four wheel drive is common for all wheel race and high performance cars

  • R4D: rear engine four wheel drive is common on off-road sports cars or buggies 

Now how does the drive type affect tuning? Generally speaking drive type layouts that move vehicle weight more to the front of the car require a more understeer setup to stabilize the car on corner entry and more front camber to compensate higher body roll at the front of the car. Conversely car types that move more vehicle weight to the rear of the car require a more oversteer setup to combat inherent understeer and more rear camber to compensate higher body roll at the rear of the car.

The following table depicts how drive type affects the different tuning areas starting with highest front weight bias down to highest rear weight bias with the common FR drive type being in the middle as the most balanced drive type,

Drive Type         Tire Pressure           Camber                ARBs                  Springs               Dampers              Brakes              Diff   

                               Front / Rear          Front / Rear        Front / Rear         Front / Rear         Front / Rear        Front Distr.     Accel / Decel

FF                        Lower / Higher       Higher1                Lower / Higher   Lower / Higher    Higher / Lower        Higher        Higher / Lower

MF                           |           ^                 ^                            |            ^              |           ^               ^            |                 ^                 ^            |  

F4D                          |          |                  |                           |            |               |           |               |            |                 |                 |           |

FR                        -------------------------------------------------------------------------------------------------------------------------------------------------------------------

M4D                        |           |                           |                 |            |               |           |               |            |                 |                 |            |

MR                           |           |                           |                 |            |               |           |               |            |                 |                 |            |

R4D                         v            |                           v                 v            |               v           |               |            v                 |                 |             v

RR                      Higher / Lower                  Higher1       Higher / Lower     Higher / Lower      Lower / Higher       Lower        Lower / Higher 

1 Higher = More Camber

So these are the basic Horizon tuning principles. With the basics being laid out we are now ready to dive into general tuning.