Part #: IS-21200-31U03. This ISR Performance thermostat is crafted for Nissan VQ35HR and VQ35VHR engines without a water port, set at a cool 68 degrees Celsius. It's an excellent upgrade for high - performance engines. Unlike the factory thermostat that opens at 78 degrees Celsius, the ISR unit kicks in at 68 degrees. This means it cools your engine before heat builds up. Once the engine is fully warmed up, it opens at a lower temperature than standard thermostats, letting coolant flow through the engine earlier. This effectively reduces and maintains cooler engine temperatures. Note that all ISR Performance products are for off - road use only. In California, they are legal only for racing vehicles that will never be used, registered, or licensed for highway use.
Using this ISR Performance thermostat is straightforward. First, make sure your engine is completely cooled down before installation. Then, carefully remove the old thermostat and replace it with this new one. Ensure all connections are secure. Remember, this product is designed only for off - road use. In California, it's for racing vehicles not used on highways. When it comes to maintenance, periodically check the thermostat to see if it's working properly. If you notice any issues with engine overheating or irregular temperature changes, it might be time to have it inspected. Keep it clean and free from debris to ensure optimal performance.
