ApexSense

Download the ZIP file using the button on this page. Extract it anywhere on your PC (e.g., C:\ApexSense\), then run ApexSense.exe. No installer required, it's a portable application. Have iRacing open and in an active session for the overlays to connect to telemetry data.

The iRacing SDK only updates tire temperature channels when the car is in the pits. Once you leave the pit lane those values freeze. ApexSense detects this stale data and activates a physics-based thermal estimation model. Estimated values show a ~ prefix (e.g., ~95°) and "EST" appears after the tire label. When you return to the pits, all values snap back to real SDK readings.

The model accounts for speed-based rolling friction, brake heat (front-biased or rear-biased depending on drivetrain), throttle/traction heat, lateral cornering forces with per-zone distribution, and weather-aware cooling using real track temp, air temp, wind speed and humidity. Tires heat up with a 30 s time constant and cool with 45 s, matching real rubber thermal behaviour. Expect temperatures to be within a reasonable range for hot/cold awareness; treat them as a guide, not a precision measurement.

Yes. ApexSense reads standard iRacing SDK channels that are available for every car. The drivetrain detection looks up the car's screen name once per session and selects the appropriate heat model (RWD, FWD, AWD, RWD Hybrid). Any car not found in the lookup table defaults to the RWD model, which is a safe fallback for the vast majority of iRacing content.

The radar overlay draws a top-down canvas showing your car in the centre and nearby cars around you. Distance is represented in metres and colour-coded: red for cars within 5 m (danger), yellow for 5–15 m (caution), and green for cars beyond 15 m (safe). You can adjust the radar range, scale, opacity, and car rectangle dimensions in the Radar settings tab.

Yes. When "Lock overlays (click-through)" is unchecked in the General settings, the overlays become draggable and you can move them anywhere on your monitor. Once positioned, re-enable the lock to make them fully click-through so they don't interfere with your mouse control in iRacing. Positions are saved between sessions.

The poll interval controls how frequently the app reads telemetry from iRacing (in milliseconds). Lower values give smoother, more responsive updates but use slightly more CPU: 50–100 ms for very smooth updates, 100–200 ms for a balanced approach (recommended), and 200+ ms for lower CPU usage with slower refresh. The app defaults to 100 ms.

Open the Tires tab in the launcher. You'll see four threshold inputs: Cold to Warming, Warming to Ideal, Ideal to Hot and Hot to Overheat. These control the colour zones displayed on the tire overlay. Defaults are 50 / 70 / 110 / 130 °C, a good starting point for most GT-class cars. For cold-weather compounds or endurance cars, you may want to shift all values down by 10-15 °C. Click Save Settings after adjusting.

ApexSense reads data exclusively from the iRacing SDK memory-mapped file, which is the official and supported way for third-party applications to access telemetry. It does not inject code into iRacing, modify any game files, or interact with the game process in any other way. Using the iRacing SDK for overlays and telemetry is explicitly permitted under the iRacing Terms of Service.

Yes, ApexSense is completely free to download and use. If you find it useful and want to support continued development, a voluntary donation via PayPal is always appreciated but never required.