We had dusted off Project FR-S for an industry track day at Buttonwillow Raceway last month. While we had run the car in the winter on small courses like Streets of Willow and shorter courses like a roval at Irwindale Raceway, this was the first time we had taken it out on a bigger longer course. When doing a long session, we noticed that the power really faded toward the end of the session. The ECU was pulling timing or not giving us full drive-by-wire throttle in a soft limp mode even though our water temperature was smack in the middle of the normal range on our gauge thanks to our Koyo radiator. Now the factory gauge isn’t the best for monitoring the engine but from doing research on what others were experiencing with forced induction track-driven FR-S’s, our oil temperature was probably moving past 260 degrees and the engine was protecting itself. At 260, bad things start to happen. The engine’s bearings are made of soft low melting point metals and they start to lose load-bearing capacity right at around 260 degrees F. If you run high-quality synthetic, your oil is still good, as long as you are not running something like 0w-20 super mileage oil but your bearings are getting softer and not happy. It is our opinion that high oil temps are one of the causes of the FA20 engine’s propensity to have oiling problems when the power is turned up on the track. For the sake of our engine, we needed an oil cooler and Greddy Performance Products came to our rescue with one of their beautiful units!
The Greddy oil cooler uses a 10-row tube and fin, heat exchanger. It is not the biggest cooler on the market but it is the biggest that will fit in the area it is designed to go in. Greddy’s mounting position on the passenger side of the front of the car is a big advantage for forced induction cars that have an intercooler. This position means that the oil cooler isn’t fighting for space in the front of the car and is not heating up air that the intercooler, AC condenser, and radiator are dividing up. We really prefer oil to air oil coolers as we find that they work much better. For coolers that share coolant with the radiator, the working cooling medium is the coolant which is usually well over 200 degrees under track conditions vs the oil to air coolers’ ambient air temperature. With an oil-to-water cooler, the oil is also dumping a lot of heat directly into the coolant which the radiator must get rid of.
The Greddy kit comes with a thermostatic oil filter adaptor, mounting brackets, and high-quality hose and fittings. Greddy also has a cooler kit that comes with an air duct which is the preferable part for track use but they were out of stock so we would have to fabricate our own.
The billet adaptor takes the place of the stock oil filter and allows the fitting of the oil coolers’ thermostat.