The following tables compare general and technical information for a number of racing simulators. Please see the individual products' articles for further information. This article is not all-inclusive or necessarily up-to-date.

Physics

Tire simulation

Note 1: with several modifications.

Note 2: "plus some integration for dynamic behaviour for the quick spinning on the Y axis of the tire (quick steer)".Post by Stefano "kunos" Casillo on DrivingItalia.net forum, accessed May 07, 2006.

Note 3: similar to models like "string model", "spring model", "brush model", "slip model".

Note 4: tire data files show parameters related to tire wall deformation, and is likely to have been implemented.

Note 5: tire pressure set at the setup before driving.

Note 6: interpolated lookup tables.

Note 7: All cars available for Racer are user created, so the source of the Pacejka data varies from car to car. There are several manufacturer-sourced Pacejka parameter sets that are commonly used.

Note 8: Flatspots can be felt through force feedback in extreme cases through corners.

Note 9: Each tire has 48 independent sampling points for heat and wear.LFS website, News item of Jun. 25th, 2005, 20:00 The 48 sections per tire are arranged as 3 across the width of the tire by 16 along the circumference of the tire.

Suspensions

Note 1: Instead of dynamically modeled suspension components, Racer uses parameters that define linear camber and toe change per unit of suspension deflection. This allows a rough approximation of the camber and toe effects that a dynamically modeled suspension has. Roll centers are static, and their placement is defined by a parameter.

Drivetrain

Note 1: No proper RWD support; the RWD cars available for testing are made by switching the front and the back end, therefore handbrake affecting to the front wheels.

Note 2: This diff behaviour can be achieved through correct setup of the active differential mappings.

Note 3: No proper 4WD support. Cars can be set to 4WD, but power distribution is always 50%/50% (front/rear), and there are no means to adjust centre diff locking. This gives the 4WD cars a tendency to understeer.

Note 4: Limited Slip Differentials (LSD), are divided in four categories: Viscous Coupling (Syncro), Clutches, EDL and Torque Biasing Differentials. The Clutches category include Passive Clutch, Progressive/Locking Clutch (Positraction or Salisbury type), Simple Hydraulic Clutch and Electronic Clutch.http://www.houseofthud.com/differentials.htm

Note 5: An active diff is a diff which can be set by the driver in the race, it is also constantly varying locks dependant on more factors than just acceleration and deceleration. Starting in 2006, the WRC has ruled that active diffs can only be used by drivers who have not placed in the top 6 in the WRC in the last 5 years. However, active center diffs are still allowed freely in competition. RBR uses simplified active diffs and the diff cannot be changed in an actual race, only in the service areas.

Note 6: Power distribution is customizable. Racer is hardcoded so that only one differential per car is allowed. Therefore in a 4WD car, all four wheels are driven, but only two of the wheels can have a "real" differential. Also, Racer does not implement a center differential for 4WD.

Road surfaces and covers that affect handling

Note 1: The physics of the interaction between tire and wet asphalt is fully implemented, but in version 1.0.1 is not used yet.
Note 2: RBR initially has a total of 132 different surfaces (be it road surfaces or elements such as different types of rocks, water... even several types of bushes and poles!).
Note 3: There are 3rd party tracks featuring non-conventional surface types, such as snow, dirt (Blackwood for GPL), rain (Nurburgring in rain), and probably more. Also, there is a track surface type (surface type 8) that was supposedly going to be used as water, however it wasn't finished and doesn't work properly. It usually results in the car sinking into it, then being launched.
Note 4: In every surface type, there are parameters such as SoilThickness and SoilDensity in RBR and WetGrip/DryGrip in ISI-based sims that can be adjusted.
Note 5: Racer surface types have several parameters that can be customized on a per track basis. Specifically, these are grip, rolling resistance and viscosity.
Note 6: Ice is only used for internal testing, not present in the official tracks yet.
Note 7: Only visible, no effect on grip.
Note 8: rFactor engine can be adapted to model any kind of surface editing a terrain data file, but at the moment there is no specific support to model the interaction of different tire models with different surfaces.
Note 9: The tire modeling supports a separate beahviour for wet surfaces, but in game there is no option for having a race happen under rain yet.

Aerodynamics

Note 1: The undertray angle is not adjustable and the undertray angle does not vary with the pitch of the car. The ground clearance of the car does not affect undertray downforce.

Note 2: The physics engine that Grand Prix Legends shipped with did not model downforce. Downforce was added to the model with the release of the 1969 mod for GPL.

Chassis

Damage

Note 1: The car doors and certain side panels cannot be damaged at the moment. This is to prevent the driver's body from being left sticking out of the car.
Note 2: Only wings and suspensions.
Note 3: Front wing.

Artificial Intelligence

Note 1: Of a rather rudimentary sort.

Note 2: Not as shipped-most AI wrecks due to bad LP lines or errors in the .ini file, but some modding has been done in this area.

Note 3: AI track learning is available in V1.087 beta or greater.

Note 4: AI Mistakes are only considered partial in rFactor because they are not convincing to anyone. As of V1.087 beta there is a *.PLR variable called "AI Mistakes".

Multiplayer

Connection quality

Note 1: More data packets are send to peers who are closer on track, network conditions permitting.
Note 2: "Yes" is good. Here, "significant" means any outright freeze of the program or a decrease or stutter of fps significant enough to impact the driving experience negatively (e.g. causing a crash or loss of control).
Note 3: Via third-party plug-in. As RBR is a rally sim, no wheel to wheel racing is included.
Note 4: A temp car (out of the box, it resembles a box on wheels) is loaded when a new peer connects and the local user is currently on track. The full car is loaded when the user goes to the pits.
Note 5: Only when cars of new joined players are loaded into garage. It is settable in multiplayer settings or .PLR file
Note 6: Settable in .PLR file

Configurability options

Sound

Note 1: Typically, this type of sound engine uses very brief samples of individual explosions and manipulates these according to various factors. While longer samples may also be used, e.g. for backfiring, these engines are called "dynamic" because they dynamically synthesize the sound of the engine. They are also known as "synthetic" for that reason.
Note 2: The game has two sound engines.
Note 3: In rFactor doppler effects are simulated, and can be adjusted through the PLR file, as the "Speed Of Sound=" variable.

Graphics

Note 1: Suspension travel is only visible in open wheeler cars (LX4, LX6, MRT, FOX, FO8, BF1). Real-time two-dimensional overlay schematic available for all cars.

References