Project DBA R35 Nissan GT-R, Keeping Limp Mode Away With More Cooling

We replaced the OEM oil cooler with an improved unit by Cicio Performance.  The core on the Cicio Performance oil cooler is 10mm thicker than stock and it has 3 more rows than the stock cooler.  The cooler also has internal turbulators to help conduct heat from the oil to the outside of the cooler. The Cicio oil cooler is about 25% for efficient than the stock cooler and 11% better than the next best performing aftermarket cooler.

The Cicio Performance cooler is a direct bolt in using the OEM tubing fittings and chassis mounts.

Here is the Cicio Performance cooler hooked up and in place. The OEM air duct also fits to direct air to the cooler.  The coolers black coating is a special thermal heat rejection coating that further improves efficiency.

A large part of avoiding the limp mode blues is the Greddy transmission cooler. The transmission overheating is the most common cause of limp mode even for short duration spurts like drag racing.  The Greddy cooler more than doubles the transmission cooling capacity.

The Greddy transmission cooler uses this thermostatic housing to relocate the stock oil to water cooler and to divert hot fluid to a large front mounted oil to air cooler.  The Greddy cooler uses the stock cooler to maintain good temperature and then when the transmission starts to get hot, move the hot fluid to the air to oil cooler after the oil to water cooler.  This prevents overcooling of the trans fluid in normal operation.  It also helps keep excess heat out of the coolant that the transmission shares with the engine.


  1. Mike, any need to upgrade the PS cooling loop? Our Z33 overheats the stock PS cooler and system with puny 255 Continentals on track days. The plan over winter is to install a large truck trans cooler in its place.

    1. The GT-R has the biggest power steering cooler of any Nissan I have seen so far. We haven’t heard of people having issues. I haven’t heard of a Z33 overheating the power steering on the track, autocross yes but not on a road course.

  2. I really like that BOV design. I think it’s time to retire the Greddy Type S I’ve had on my car for the past 10 years.

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