When it comes to maximizing performance and reliability in motorsports, monitoring exhaust gas temperature (EGT) is essential. An EGT probe provides critical data about combustion efficiency, turbo health, and air/fuel ratios—helping drivers and engineers prevent costly engine failures and achieve optimum engine performance.
But to get accurate readings, an EGT probe must be installed correctly. In this guide, we’ll cover everything you need to know about choosing the right mounting method, proper placement, and best practices for long-lasting, reliable performance.
Why Proper Installation Matters
An incorrectly installed EGT probe can produce misleading data or lead to engine failure under the extreme heat and vibration of racing. The result? Missed tuning opportunities, reduced performance, and potential engine damage. Proper installation ensures:
- Accurate, real-time exhaust gas readings
- Leak-free, durable mounting
- Easier serviceability and probe replacement
- Maximum sensor life under racing conditions
Step 1: Choosing the Right Mounting Method
There are three common ways to mount an EGT probe. Each has unique benefits depending on your setup.
1. Drill & Tap
This method involves drilling and threading a hole directly into the exhaust manifold, header, or pipe.
- Cost-effective and simple
- No extra hardware required
- Easy to swap compression fittings for different probe diameters
- Requires precise drilling to avoid leaks
- Threads may wear over repeated use
2. Weld Bung with Compression Fitting
A threaded bung is welded onto the exhaust, and the compression fitting threads into the bung.
- Strong, durable, professional installation
- Easy to swap compression fittings for different probe diameters
- Requires welding expertise and more setup time
3. Direct Weld Compression Fitting
The compression fitting itself is welded directly to the exhaust.
- Extremely robust and permanent
- Minimal leak points
- Not easily serviceable—probe size is fixed
- Requires welding expertise and more setup time
Pro tip: If you want flexibility for different probe sizes, choose Drill & Tap or Weld Bung with Compression Fitting. If you want a permanent, race-only install, Direct Weld may be your best bet.
Step 2: Finding the Best Probe Location
Placement is just as important as the mounting method.
- Gasoline engines: Install the EGT probe 1–2 inches from the exhaust port on the header or manifold for fast, accurate response.
- Diesel engines: Position the probe pre-turbo for precise tuning or post-turbo to monitor turbine performance and exhaust temps.
- Multi-cylinder engines: Install probes in each primary runner or at least on the hottest cylinder for accurate monitoring.
Avoid placing probes too far downstream—this delays response time and can under-report exhaust temps.
Step 3: Preparing and Installing
- Mark your location and drill a hole sized for your fitting or bung.
- Tap threads if using Drill & Tap, or weld the bung/fitting securely.
- Insert the probe to the proper depth—generally placing the tip in the center of the exhaust gas stream, not flush with the pipe wall.
- Tighten the compression fitting—firmly, but not over-tightened. Crushing the EGT probe sheath can damage it.
- Check for leaks and verify probe stability under vibration.
Step 4: Wiring and Protection
EGT probes operate in harsh environments, so wiring must be carefully managed.
- Use matching thermocouple extension wire (e.g., Type K for Type K EGT probes).
- Route cables away from hot engine components such as headers, turbos, and also sharp edges.
- Add heat shielding and braided sleeving for protection.
- Provide strain relief at connectors to prevent fatigue failures.
Step 5: Testing and Calibration
Once installed:
- Power your system and verify the probe is sending a signal.
- Confirm the temperature rises smoothly with engine load.
- Cross-check readings with known conditions (e.g., compare to other probes or dyno data).
Remember: thermocouples themselves are not calibrated in the field—it’s the gauge, ECU, or DAQ system that must be configured correctly to match the probe type and range.
Final Thoughts
A properly installed EGT probe is one of the best tools for protecting your engine and fine-tuning performance. By choosing the right mounting method, placing the probe correctly, and following wiring best practices, you’ll get accurate, reliable temperature data that can make the difference between winning a race and blowing an engine.
Explore our full line of extreme-duty EGT probes designed to survive the toughest motorsports environments.