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

The internal construction of the CSF radiators core has some innovative features. One of these is the B-Fin tube. On a conventional radiator, there are rows of oval-shaped tubes. Factory radiators usually have two rows and aftermarket radiators have as many as 4.  This gives more cooling area but the air has a problem penetrating the core and doing heat exchange.  The CSF core has one big tube in a single row.  CSF calls this their B tube.  The B Tube starts off as a sheet of aluminum that is folded back onto itself to form a B shape to the desired width. After forming the seam of the tube is furnaced brazed to make it one piece and leak-free. The B-Tube gives the ideal ratio of fluid to air exposure with the center B pillar giving strength and an additional conduction path for heat to follow from the fluid to the outside of the tube. The one-piece construction also makes it easy for air to penetrate the core, helping with heat exchange and cooling.

In-between the B fin tubes are these heat-conducting turbulators. These provide a path for heat out of the tubes to the airstream in radiators. Another innovation from CSF is that the turbulators are louvered.  This helps improve airflow through the core and helps improve heat exchange efficiency. You can see the louvers here. CSF’s core is dual row and a thick 42mm.  The CSF radiator is rated at 1000 hp.

To replace the stock radiator, we needed to undo the power steering cooler and evacuate the air conditioning system.  Then we could loosen the AC condenser and tilt it forward enough to remove the stock radiator.

Next we could slip the CSF radiator into place.  Even with the much thicker core it fit right in place.

The AC condenser went right back in and we bolted the power steering cooler back in place.

The factory twist mounts were tightened back down.  Now the AC system was recharged and the hoses were reconnected.  Our CSF radiator is now ready to be run.


  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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