Toyota GR86 User Manual

General Information

A Message From iRacing: The Toyota GR86 is the official car of the all-new Toyota GR Cup, a single-make road racing series. Announced in 2022, each GR86 is transformed into a racing machine by Toyota Gazoo Racing North America engineers. The GR Cup is designed for amateur drivers, welcoming up-and-comers, casual drivers, and retired legends. Custom modifications include a six-speed sequential transmission and aggressive new bodywork.

This guide explains how to get the most out of your new car, from adjusting settings off-track to understanding the cockpit display.

Tech Specs

Power Unit: Naturally Aspirated 2.4 Liter 4-Cylinder Boxer

Chassis: McPherson Strut Front Suspension, Double Wishbone Rear Suspension

Getting Started

Before starting the car, it is recommended to map controls for Brake Bias, Traction Control, and ABS adjustments. This allows for quick changes to driver aid systems on the track.

To get started, select the "upshift" button to put the car into gear and press the accelerator. The car uses a sequential transmission and does not require a clutch. Downshift protection prevents downshifting if the speed is too high for the selected gear. Upshifting is recommended when the final shift light illuminates red at 7100 rpm. All shift lights flash red at 7200 rpm as a warning.

Loading an iRacing Setup

The iRacing Baseline setup is automatically loaded when you enter a session. To select other pre-built iRacing options, go to Garage > iRacing Setups. To customize a setup, make changes in the garage and click "Apply".

You can save your custom setups by clicking "Save As". Your saved setups can be accessed under "My Setups". To share a setup, use the "Share" option. Shared setups from other drivers can be found under "Shared Setups".

Dash Configuration

The Toyota GR86 features a single-page, dash-mounted display for engine data and race information.

Upper Group

• Best Lap: The session's fastest lap time.
• Current Lap Delta: The difference in time from the current lap to the session's best lap. Green indicates faster, red indicates slower.
• Current Lap Time: A live display of the time elapsed on the current lap.
• Fuel Used: The amount of fuel consumed since leaving the pits or the start of the race.
• Predicted Lap Time: A lap time prediction based on the current lap delta and prior lap times.

Center Gauges

• Oil Temperature: Engine oil temperature shown in a gauge and numerical format. The gauge changes color for dangerous temperatures.
• Tachometer: Engine RPM displayed digitally, changing from white to red near the optimal shift point and rev limiter.
• Gear Indicator: The currently selected gear, displayed within the tachometer.
• Water Temperature: Engine cooling water temperature shown in a gauge and numerical format. The gauge changes color for dangerous temperatures.

Lower Group

• Speedometer: The car's current speed in MPH or KPH.
• AC Mode: Inoperable, displays "0".
• TC Mode: Currently selected Traction Control System setting (reflects garage and F8 black box settings).
• ABS Mode: Currently selected Anti-Lock Braking System setting (reflects garage and F8 black box settings).

Warning Banner: A warning banner across the top of the dash and illuminated LEDs on the sides indicate major issues such as low fuel pressure, low oil pressure, or high oil/water temperatures.

Advanced Setup Options

This section covers advanced chassis tuning. Adjustments can significantly alter vehicle handling. It is recommended to make incremental changes and adjust only one variable at a time.

Tires

Tire Settings

• Starting Pressure: Air pressure when the car is loaded. Higher pressures reduce drag and heat but decrease grip. Lower pressures increase drag and heat but increase grip. Higher speeds and loads require higher pressures.
• Last Hot Pressure: Air pressure after returning to pits. The difference between cold and hot pressures indicates balance progression. Similar tires should build pressure at similar rates.
• Last Temperatures OMI: Tire carcass temperatures after returning from pits. Reflects wheel loads and tire work. Center temperatures compare tire work; inner and outer temperatures analyze wheel alignment. Measured in three zones across the tread.
• Tread Remaining: Amount of tread left after returning from pits. Helps identify alignment issues (e.g., uneven wear) and analyze handling balance in conjunction with temperatures. Measured in three zones across the tread.

Chassis

Front

• ARB Size: Alters front suspension roll stiffness. Options: Stiff, Soft, Disconnected. Stiff increases roll stiffness and understeer. Soft reduces roll stiffness and understeer. Disconnected greatly reduces roll stiffness, inducing oversteer and potential instability.
• ARB Setting: Fine-tunes front suspension roll stiffness. For Stiff/Soft ARB sizes, lower values stiffen the assembly and induce understeer; higher values soften it and reduce understeer. No effect if ARB is disconnected.
• Toe-in: Angle of front wheels relative to the chassis centerline. Positive is toe-in, negative is toe-out. Toe-out decreases straight-line stability, aiding turn-in response but risking slip. Toe-in reduces turn-in responsiveness and front tire temperature buildup.
• Bump Rubber Length: Adjusts the height of front suspension bump rubbers, affecting engagement and suspension stiffness. Longer engagement increases stiffness, improving aero platform control and high-speed stability, but reduces low-speed grip and rough surface absorption.
• Cross Weight: Percentage of car's weight on Right-Front and Left-Rear tires. Influences asymmetric handling. Above 50% induces understeer in left turns and oversteer in right turns. Below 50% induces oversteer in left turns and understeer in right turns. Aim for 50% for road courses.
• Nose Weight: Percentage of car's weight above the front axle. Higher nose weight induces understeer; lower nose weight induces oversteer. Non-adjustable, varies with fuel level.

In-Car Dials

• Brake Pressure Bias: Percentage of braking force sent to the front. Locked at 50% on the GR86.
• Brake Pads: Options: High Friction (most braking force, difficult to modulate), Low Friction (least braking force, easy to modulate), Medium Friction (compromise).
• ABS Setting: Controls Anti-Lock Brake system intervention. 1-3 (3 most, 1 least). 0 disables ABS.
• TC Setting: Controls Traction Control system intervention. 1-3 (3 most, 1 least). 0 disables TC.

Front Corner Details

• Corner weight: Weight on each wheel in static conditions.
• Ride height: Distance from ground to a chassis reference point behind front tires.
• Fender height: Height of the fender from the ground.
• Spring rate: Stiffness of suspension springs. Higher values mean stiffer springs.
• Spring perch offset: Adjusts ride height and corner weight by changing spring preload. Decreasing value increases preload, raising height. Increasing value decreases preload, lowering height. Adjust in pairs or all four to maintain crossweight.
• Bump stiffness: Shock stiffness under compression (e.g., during braking). Higher front bump stiffness can induce understeer under braking and turn-in. Lower values soften the shock, reducing understeer.
• Rebound stiffness: Shock resistance to expansion (e.g., under acceleration). Lower values make front shocks more resistant to expansion, potentially inducing understeer on acceleration. Higher values decrease resistance, potentially increasing front grip and reducing understeer.
• Camber: Vertical angle of the wheel. Negative camber is desired. Higher negative camber increases cornering force but reduces longitudinal grip under braking. Excessive camber reduces tire life.

Rear Corner Details

• Corner weight: Weight on each wheel in static conditions.
• Ride height: Distance from ground to a chassis reference point ahead of rear tires.
• Fender height: Height of the fender from the ground.
• Spring rate: Stiffness of suspension springs. Higher values reduce aerodynamic pitch sensitivity but decrease rear mechanical grip and can induce oversteer. Softer springs increase mechanical grip and can induce understeer but may affect aerodynamic stability.
• Spring perch offset: Adjusts ride height and corner weight by changing spring preload. Decreasing value increases preload, raising height. Increasing value decreases preload, lowering height. Adjust in pairs or all four to maintain crossweight.
• Bump stiffness: Shock stiffness under compression (e.g., under throttle). Higher rear bump stiffness can increase traction on throttle. Lower values soften the shock, reducing understeer during acceleration.
• Rebound stiffness: Shock resistance to expansion (e.g., under braking). Lower values make rear shocks more resistant to expansion, potentially inducing understeer during braking. Higher values decrease resistance, potentially decreasing rear grip and inducing oversteer during braking.
• Camber: Vertical angle of the wheel. Negative camber is desired. Higher negative camber increases cornering force but reduces longitudinal grip under acceleration. Excessive camber reduces tire life.
• Toe-in: Angle of the wheel relative to the chassis centerline. Positive is toe-in, negative is toe-out. Rear toe-out decreases straight-line stability and can cause spins. Rear toe-in increases straight-line stability and reduces turn-in responsiveness.

Rear

• Fuel level: Amount of fuel in the tank when leaving the garage. Affects nose weight and handling balance.
• ARB Size: Rear Anti-Roll Bar. Options: Soft (connected), Disconnected. Soft increases rear roll stiffness and induces oversteer. Disconnected decreases rear roll stiffness and induces understeer.
• ARB Setting: Fine-tunes rear ARB stiffness (Soft setting only). Setting 1 is softer (understeer); Setting 2 is stiffer (oversteer).
• Wing setting: Rear wing angle of attack. Higher values (10, 15 degrees) produce more downforce and drag, shifting aero balance rearward (understeer). Lower values (5 degrees) reduce drag and downforce, shifting aero balance forward.