The modifying continues......

Since upgrading the engine and turbo charger, there were two vital systems that had been neglected, the cooling water system and the oil cooling system. Like a lot of mods, the car doesn't "need" these, but it didn't need a lot of things so its just become a labour of love and an all encompassing hobby.

The standard STi radiator and oil cooler were actually good enough for between 400 - 500 Bhp but over long term use under high load, its probably best to help maintain the overalll quality and consistency of the engine by helping out its cooling system a little more. Higher oil temps lead to the oil breaking down sooner as its under constant abuse from not only temperature but pressure between bearings as its flows through the block. Naturally a good synthetic oil will take this abuse as long as you change regularly but by cooling it through a better cooler, you just make life easier for it, which in turn has a positive effect on its cooling abilities and also means that it is free to do its other job - remove ash, soot and carbon and hold it in suspension. Excess heat will seriously hamper this effect so by improving cooling, your adding to the overall "big picture".

Again, the same applies with the radiator as when you increase the pressure of a fluid, you raise its boiling point, so that means your coolant can work at a higher temp without starting to boil in your pipework. If this happens, then you get "gassing up" and these air bubbles can find their way around the system to the suction side of your water pump. When the pump sucks air….it can't discharge any fluid. No fluid flow, means no cooling…..turning your lovely custom built engine into an expensive coffee table!

Therefore I decided to go for the following:

Mishimoto X-Line radiator

Mishimoto Radiator hoses and temperature sensor adaptor

Hel Oil

On top of this Im getting a full engine oil and filter change and also getting the gearbox oil and read differential oil changed to a performance spec above the standard Subaru oil. Now that the transmission has to handle more power, its only fair it gets better oil to help it cope!

Ill write up another entry once the parts are fitted and the car is out of hibernation from winter!