Description
High-Performance Racing Thermostat for Hemi Engines
Upgrade your Chrysler or Dodge Hemi-powered vehicle with the iFJF Racing Performance Thermostat. Engineered to open at a lower temperature than the OEM thermostat, this upgrade allows coolant to circulate earlier, keeping your engine running cooler under hard driving conditions. Whether you're hitting the track, towing heavy loads, or pushing your Hemi on the street, reduced engine temperatures mean more consistent power, less knock retard, and extended engine longevity.
Vehicle Compatibility
| Make |
Model |
Year Range |
Engine |
| Chrysler |
300 / 300C |
2005-2013 |
5.7L / 6.1L / 6.4L Hemi |
| Dodge |
Charger |
2006-2013 |
5.7L / 6.1L / 6.4L Hemi |
| Dodge |
Challenger |
2008-2013 |
5.7L / 6.1L / 6.4L Hemi |
| Dodge |
Magnum |
2005-2008 |
5.7L / 6.1L Hemi |
Key Features & Benefits
-
Lower Activation Temperature: Opens at a reduced temp vs OEM, allowing earlier coolant flow and better heat management
-
Consistent Power Output: Prevents heat soak and timing pull under high-load conditions
-
Extended Engine Life: Reduced thermal stress on pistons, rings, and head gaskets
-
Direct Fit Replacement: Designed to fit the stock thermostat housing — no modifications required
-
Track-Tested Design: Popular upgrade among Hemi drag racers and road course enthusiasts
Technical Specifications
| Specification |
Detail |
| Part Number |
FJ-TAT02-06L |
| Material |
Brass & Stainless Steel |
| Compatible Engines |
5.7L Hemi, 6.1L Hemi, 6.4L Hemi |
| Installation |
Direct bolt-in, stock housing |
| Application |
Street Performance / Track / Towing |
Why Upgrade Your Thermostat?
Factory thermostats are calibrated for emissions compliance and cabin heat — not performance. Under spirited driving or track use, the stock thermostat keeps the engine in a higher temperature range that triggers ECU timing retardation. By installing a racing thermostat, you create a thermal buffer that helps your Hemi maintain optimal timing advance and horsepower output across the entire powerband.
Frequently Asked Questions
Q: Does this thermostat work with stock cooling systems?
A: Yes. It installs in the factory thermostat housing and works with the stock radiator, water pump, and cooling fans. No other modifications are required.
Q: What temperature does this thermostat open at?
A: This racing thermostat opens at approximately 180°F, compared to the factory 203°F thermostat. This provides a 20-25°F thermal buffer during hard driving.
Q: Will this cause a check engine light?
A: In most applications, no. However, if you live in an extremely cold climate and the engine fails to reach operating temperature quickly, the ECU may set a P0128 code. This is rare and typically only occurs in sub-zero conditions.
Q: Is this thermostat compatible with aftermarket tunes?
A: Yes, and it actually works very well with performance tunes. Many tuners adjust fan activation temperatures to complement a lower-temp thermostat for maximum cooling efficiency.
Q: Does this fit the 6.4L Apache / 392 Hemi?
A: This thermostat fits Gen III Hemi engines including the 6.4L (392) Apache variant found in later SRT models. Verify your specific year and model compatibility in the table above.
