2-Channel Dual EGT Digital DPG-XR Pyrometer Gauge + Probe Kit - Gas Race Series EP

The DPG-XR Gas Race Series kit combines a dual-channel digital pyrometer gauge with two EP Series exposed-junction Type K EGT probes. This configuration is designed for gasoline performance and racing applications where fast, accurate response to exhaust temperature changes is critical.

The EP Series probe uses an exposed, ungrounded thermocouple junction, allowing it to respond quickly to changes in exhaust gas temperature. With a response time of approximately 250 milliseconds, it is well suited for applications where mixture and ignition timing adjustments must be observed in real time.

Kit Contents

• DPG-XR Series 2-Channel Digital Pyrometer Gauge (1) 
• EP Series Gas Racing EGT Probes, 3/16" diameter, exposed ungrounded junction (2) 
• 316 stainless steel adjustable double-ferrule compression fittings, 1/8"-27 NPT male thread (2) 
• Thermocouple connectors (2) 
• Weld bungs (optional, selected at checkout) 

The Defining Difference: Exposed vs. Sheathed Junction

Choosing between the Gas Race EP kit and the Diesel Commercial DP kit comes down primarily to thermocouple junction type.

An exposed junction places the sensing element directly in the exhaust gas stream with no intermediate barrier. This allows the probe to respond very quickly to changes in exhaust gas temperature.

The tradeoff is reduced resistance to contamination in chemically aggressive exhaust environments such as diesel or high-sulfur fuel systems, where a sheathed probe is more appropriate.

Why Exposed Junction Matters in Gasoline Applications

In gasoline performance and racing environments, exhaust gas temperature is used as a real-time indicator of combustion behavior.

When adjustments are made to:

• Carburetor jetting 
• Air/fuel ratio targets in EFI systems 
• Ignition timing 

…the resulting temperature change must appear on the gauge quickly enough to be useful during a dyno pull or on-track operation.

The EP Series probe’s exposed junction allows the sensor to respond rapidly to these changes, making it well suited for tuning applications where responsiveness matters.

Additionally, the exposed junction design allows for easy visual inspection of the sensing element, which can be beneficial in race environments where probes are frequently checked, removed, or replaced.

Understanding Response Time

The EP Series probe has a specified response time of approximately 250 milliseconds. This value represents the time required for the probe to reach 63.2% of a sudden temperature change (the standard thermocouple time constant definition).

Full stabilization occurs over multiple time constants, but this response speed is sufficient to track dynamic temperature changes in gasoline engines during tuning and operation.

What EGT Measures in a Gasoline Engine

Exhaust gas temperature (EGT) is an indirect indicator of combustion efficiency and air/fuel ratio.

• As the mixture leans toward stoichiometric, combustion efficiency increases and EGT rises 
• Peak EGT occurs near or slightly lean of stoichiometric 
• Maximum power is typically achieved at richer mixtures (approximately lambda 0.85–0.90) 

Because of this relationship, EGT is used to track relative changes rather than absolute targets. Monitoring EGT allows detection of mixture imbalance, ignition issues, or cylinder-to-cylinder variation.

EP Series Probe Construction

Inconel Sheath and Exposed Junction

The probe body is constructed from Inconel, a nickel-chromium alloy that maintains structural integrity at elevated temperatures typical of gasoline exhaust systems. The exposed junction at the tip allows direct contact with exhaust gases for fast response.

The junction is electrically ungrounded, meaning it is isolated from the probe sheath. This helps minimize electrical noise and reduces susceptibility to ground loop interference.

Cable Construction

The probe uses 20 AWG stranded thermocouple wire insulated with PTFE (Teflon) and protected by a stainless steel over-braid.

• PTFE insulation provides high temperature resistance and chemical durability 
• Stranded conductors improve flexibility for routing in tight engine compartments 
• Stainless over-braid protects against abrasion and mechanical damage 

Compression Fitting

Each probe includes a 316 stainless steel double-ferrule compression fitting with 1/8"-27 NPT male threads.

The double-ferrule design provides:

• Secure mechanical retention under vibration 
• Reliable sealing under thermal cycling 
• Adjustable insertion depth for proper probe positioning 

Probe Specifications

• Thermocouple Type: Type K 
• Temperature Range: -148 to 2372°F (-100 to 1300°C) 
• Accuracy: ±0.4% of reading (Special Limits of Error) 
• Probe Diameter: 3/16" (0.187") 
• Sensing Junction: Exposed, ungrounded 
• Response Time: 250 ms (time constant) 
• Sheath Material: Inconel 
• Cable: Stainless over-braid with PTFE-insulated stranded wire, 20 AWG 
• Compression Fitting: 316 stainless steel, double ferrule, 1/8"-27 NPT 

Probe Placement Guidelines

For accurate measurement:

• Install probes 2–4 inches downstream of the exhaust port 
• Mount in the primary exhaust runner, not the collector 
• Position the probe tip near the center of the exhaust flow 
• Avoid contact with pipe walls 

Proper placement ensures accurate, responsive readings representative of combustion temperature.

Cable Routing Considerations

Route cables away from high-temperature exhaust components. While PTFE insulation is highly heat resistant, prolonged exposure to extreme surface temperatures can degrade insulation over time.

• Maintain clearance from headers and collectors 
• Use heat shielding where necessary 
• Allow slack for engine movement 

DPG-XR Gauge Features

• Dual-channel thermocouple input 
• Sequential display of both channels 
• 4-digit LED display with 9 selectable colors 
• Peak hold function (3 samples/second) 
• Programmable high-temperature alarm with 2A relay output 
• User-adjustable temperature offset per channel 
• Compatible with Type K, J, T, and E thermocouples 

The gauge operates on 9–28 VDC and is suitable for both automotive and industrial applications.

Typical Applications

• Carbureted racing engines (drag, circle track, autocross) 
• EFI performance tuning (street, road race, dyno tuning) 
• Turbocharged gasoline engines 
• Two-stroke racing engines 
• High-performance marine gasoline engines 

Summary

The DPG-XR Gas Race Series kit provides a fast, responsive EGT monitoring solution for gasoline performance applications. The exposed-junction EP Series probes deliver rapid response to temperature changes, while the dual-channel DPG-XR gauge provides clear, actionable data for tuning and engine protection.

For gasoline racing environments where responsiveness and visibility are critical, this configuration offers a reliable and effective measurement solution.