The 797 Performance cooling system flow controller is a device that controls the flow of coolant in the system. It does not regulate temperature, but it does slow down the speed of the coolant moving in the system. Contrary to popular belief, more doesn’t always mean better! Removing a thermostat in an engine can often lead them to run hotter or overheat.
Why?
When coolant moves too fast in the system it circulates through the radiator not allowing it to cool. By slowing the flow down, it allows more of a Delta T. (temperature in vs temperature out)
Why are there multiple sizes?
Because our product is controlling coolant flow and not temperature with the device ambient conditions are a factory. Someone in a colder dry climate may require more or less flow than someone in a hot and humid area of the country.
What size do you use?
Let’s come back to that because fan tuning is very important.
Is tuning required and what settings are used?
Tuning is required, just like a 180F thermostat requires tuning. However, thermostat tuning varies based on who is tuning it. Some tuners just drop the temperature very low forcing fans to turn on at a very low temp, and others drop the setting (many of them) by a range so the fans function like factory with adjusted lower values. The factory setting of the thermostat is 203F, by reducing each setting by 20-23 degrees would be the ideal strategy. The other method of forcing fans on all the time can overcool. We also think this method is what causes the high mortality of 180F thermostats as it forces them to exercise more often causing spring fatigue failure.
So what size do you use?
We don’t know what's best for you, and we won’t tell you. This is not a cocky answer, we just don’t know where you live, what your engine setup is, and what you require. But if you have properly adjusted fan settings, we suggest starting with the middle-size controller (Black) and adjusting up or down in size as needed. Typically, the middle plate size will result in coolant temps of 185F pretty consistently.
Will warm-up be affected, and will you have heat?
Warm up will take a little longer and the entire system is always circulating coolant. However, with proper fan tuning, the fans won't turn on until temperatures are reached and the system will still come to temperature. On colder days, it will take longer. Once again, proper tuning is important here. Heat will work as normal, we have tested these rigorously in the winter, but once again tuning plays a major factor in the warm-up cycle.
Coolant Temprature Changes:
It is normal for there to be temperature changes when coming to a stop, or when driving hard. These changes are small, usually 10 degrees or less. This is normal.
Installation notes:
Install as a regular thermostat, but clock device with the integrated bleed hole in the 12 o’clock position. Properly bleed the system. Do not install without proper tuning.
Beware of knockoffs:
Our controllers are made from 6061-T6 heat-treated aluminum and anodized for wear protection. We color code our products for size identification and never laser the sizes into them. Lasering the surface removes the protective layer and can result in oxidation and cavitation. Always buy the original from 797 Performance. We do sell these on Amazon and eBay too, but the seller will be 797 Performace.
This product is for off-road / racing use only!