GT3 cars in iRacing carry more tire data than most drivers ever see. Temperatures, pressures, and wear rates are all recorded lap by lap, but the default in-game display buries that data inside the multi-function display, which takes your eyes off the track when you need it most. The better approach is to route that GT3 tire data in iRacing to a second screen and keep it visible at all times, without lifting a finger mid-race.
Also See
➡️ Setting Up SimHub for iRacing
Why GT3 Tire Data Is Hard to See in iRacing
iRacing’s GT3 cars expose tire data through the car’s black box, accessed with F2 by default. You can see tire temperatures, pressures, and wear there, but only by tabbing through on-screen menus while the race is running. On a new set of tires, or when pressures are drifting in a long stint, you want that data visible at all times without taking your hands off the wheel.
A second screen solves this completely. Once configured, you get a permanent readout of tire temps, pressures, and wear with no mid-race input required. This is standard practice for GT3 drivers serious about managing long stints, and the setup takes about an hour once you know what to configure.
What You Need
The setup requires a second monitor, tablet, or phone with display software installed. SimHub is the community standard for this. It reads iRacing’s telemetry output in real time and can broadcast that data to any device on your local network or display it directly on a second monitor connected to your PC. The base version of SimHub is free, and the configuration for tire data requires no paid add-ons.
You will also need a GT3-specific DDU dashboard layout. Several iRacing community members have built and shared layouts that pull all four corners of tire data into a single compact display, including inner, middle, and outer temperature zones per tire. These are available through the SimHub Dash Studio community library and on various sim racing forums. Search for “GT3 tire DDU iRacing” to find actively maintained versions.
Why GT3 Cars Need a Specific Dashboard Layout
Most iRacing cars expose tire data cleanly through the telemetry channels that SimHub reads by default. GT3 cars add complexity because pressure targets and compound-specific wear curves differ by car model, and some GT3 cars do not surface all tire data through the standard HUD channels in the same way as other car classes. A generic SimHub layout may show incomplete data or miss per-zone temperature breakdowns entirely.
The community-built GT3 DDU layouts account for this by mapping the correct iRacing telemetry properties to each display element. If you build your own layout from scratch, the key properties to target are TireTempLF/RF/LR/RR for average temperatures and the zone-specific variants available in SimHub’s iRacing property list.
Setting Up GT3 Tire Data on a Second Screen
Install SimHub and point it at your iRacing installation during the initial setup wizard. SimHub will locate the telemetry output path automatically. Once installed, open Dash Studio and confirm that tire temperature and pressure properties are populating by running a quick test session with any GT3 car.
Download a GT3 tire DDU layout from the SimHub community library. Install the layout and assign it to a secondary monitor output in SimHub’s screen configuration, or use the SimHub companion app to broadcast to a tablet or phone on the same network. Set the data update rate to 10Hz or higher for accurate real-time readings. Lower update rates introduce visible lag between actual tire state and what you see on screen.
Before using the display in a race, run a 15-minute test session to confirm all four tires are reporting data and that temperatures read sensibly across the three zones. A cold tire should show even or slightly inner-heavy temperatures. A tire at working temperature will balance across inner, middle, and outer zones depending on your setup and driving style.
How to Read GT3 Tire Data During a Race
The most useful data at a glance is the three-zone temperature per tire. This tells you whether your setup is loading the tires correctly across the contact patch. An outer-heavy temperature reading on the front tires is a sign of understeer. Inner-heavy temps on the fronts suggest the car is turning in aggressively but not carrying the load through the apex. Both patterns are visible in a single glance at your DDU display, which gives you information to act on at the next pit stop.
Tire pressure is the second metric worth watching in real time. GT3 pressures in iRacing drift with temperature over a stint, and knowing whether you are inside the target window helps you decide whether a pressure adjustment at the pit stop is worth the time. Most GT3 cars have a usable window of roughly 0.2 bar above and below the target pressure before lap time starts to degrade noticeably.
Wear is more useful as a between-stint diagnostic than a real-time warning. By the time wear differences appear across tires, the setup or driving pattern that caused them has usually been running for several laps. Use wear data after a stint to identify what changed and adjust for the next run.
A Quicker Option If You Are Not Ready for a Second Screen
If the full DDU setup is more than you want to tackle right now, there is a built-in shortcut. In iRacing’s driving controls, assign a button on your steering wheel to cycle through the black box pages. This gives you access to tire data without touching the keyboard, and without taking both hands off the wheel at once. It is not as clean as a dedicated external display, but it brings the same data within reach of a single button press.
For serious GT3 racing, the second screen approach is worth the one-time setup investment. An hour of configuration gives you permanent visibility into the four metrics that matter most for managing a GT3 car across a full race stint. Once you have raced with a live tire display, going back to guessing at tire state from feel alone becomes very difficult to justify. You can download the latest version of SimHub from the SimHub official site.
