In the world of Automotive Egnineering, cooling and temperature managment are a prime concern. Taking a motor and its componenets to the limit will generate heat, a lot of heat. We need to utilize known concpets to reduce and manage overheating the:
For everyday driving a Subaru with an FB engine and CVT/Manual, overheating is not a major concern. The concepts in this document aim to better prepare the would be high-reving enthusiast for a more reliable experience.
LIMP MODEEver Heard of it? If you haven't experienced it, then you're lucky. You're also not pushing the engine to its fullest extent. That being said, you don't neccesaraly need to over tax the engine and cooling system to have fun. Enjoy with the notion that when you run the car hard, it will get hot.
Primary factors for entering limp mode, are over use, abuse, or simply prolognned high revs without sufficient cooling. The Limp mode can be "felt" as a reduction in power delivered by the enigne. Another tell tale sign is the engine will be limited to a maximum of ~4000RPM. FB20/FB25
In any case, reducing the heat in the engine bay, and its various sensors will help keep the vehicle at maximum engine performance.
Most engines rely on their oil to keep the engine cool and lubricated. The FB Series Subaru engines are no different. If you run the car in hotter climates, like summer weather, using a thicker oil will help protect the engine components. A 0w-20 is typically recomeneded by Subaru for North American and some European countries. However the use of 5w-30, and even 5w-40 is permissiable. Using 5w-30 increases the upper temperature by 10C. This is perfect for a motor which will see higher temperatures due to full load use.
They say a poormans solution to power is gearing; but with gearing comes great responsibilty. Excessive heat coming from a high reving transmission can be the quickest ticket to end of happy days. The CVT fluid in the TR580 is highly picky about its operating temperatures. Too cold, and the car feels lurchy and inconsistent when accelerating or engine braking. Too hot, and you endanger the mechanical parts from exceeding there design parameters, in worst case, slipping a chain and friction scoring the varators. However, the TR580 CVT is rather dummy-proof. It knows what temperature is too much. Like oil, if you run the CVT fluid too hot, the vehicle will enter limp mode.
Ways to keep the transmission fluid and casing cool. In a previous transmission chapter, we covered the use of transmission coolers. While not completely neccesary, they do help prolong high load and high reving engine activities.
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