I am sure that a lot of you guys are finding that even with an oil cooler you are still running really hot oil temps. During my first track day this season I was flirting with 250 degrees on a fairly cool day. To help alleviate the heat I vented my hood but still was seeing 260 degree temps on a slightly warmer day. And of course, running with oil temps at or above 260 degrees is not a good idea.
This was really starting to concern me as I am finally starting to run decent lap times and I know that as my lap times decrease my oil temps are only going to increase.
The following paragraph can be skipped by any of you experienced guys… Ok, to begin. Our cars are cooled by radiators. Yes, even the oil cooler is a radiator albeit with oil rather than water. And radiators depend heavily on direct air flow through them. Anyone with an oil cooler in a cold climate will attest that a piece of cardboard placed in front of your oil cooler will effectively eliminate its effectiveness.
Taking a look at how air flows through the nose of our cars reveals some real issues. First, a large part of our oil cooler is blocked by the crash bar and any hot air exiting through it goes directly into the radiator. Also, almost 50% of our radiator is completely blocked of any air at all. Initially, I thought of removing or modifying the crash bar but quickly realized this would leave nowhere to attach the tow hook and god forbid if I hit something head on…
I knew that I would need to increase the efficiency of my existing oil cooler. I only hoped that there was enough unused potential in it. I saw how Clintfocus at MotoIQ created a box around his oil cooler to prevent air from escaping around the oil cooler. However, I also know that Clintfocus has continued to have issues with high oil temps. In my highly untrained opinion, the box design may seal the oil cooler but still limits the amount of air available to it.
What I wanted to do is maximize the amount of available air flow directly into my oil cooler. I did this in two ways. First I fabricated aluminum baffles that would direct a larger volume of air into the oil cooler.
Second I sealed the top of the oil cooler with additional aluminum and high temp rtv sealant to prevent any air from escaping over the oil cooler.
It was at this point I realized that my oil cooler baffles blocked almost all direct airflow into my radiator. I thought “this can’t be good” and then I remembered seeing some pictures of the NISMO RC cars having circles cut out of the top of the nose. I removed the front fascia and took a look. It was apparent that if you remove the Styrofoam bumper protection you have clear and direct access to the unused part of our radiator.
So out came the Dremel tool and I gave my Z a set of nostrils.
I tested this setup at Summit Point last week and my oil temps never rose above 240!