It's actually a tranny cooler...

http://www.bmracing.com/products/acc...perCooler.html

Part number 70264, 11"x6"x1-1/2", bar and plate.

My RX-7 is used for rallycross, so a lot of full throttle, low speed, high RPM driving. My factory oil cooler broke, and a friend has this one for sale. What have you guys gotten away with for this type of driving (probably similar to autocross, run times are typically around 90 seconds).

 

from my understanding the factory oil cooler is sweet and that other non rx7 racers source out our oil coolers instead of aftermarket.

 

Only because they are fools.

The RX-7 oil to air cooler on first gens is crap. It works well only because it is massive.

I have replaced mine with a properly designed and built oil cooler (from a Harley V-Rod), which is 1/2 the size and thickness, and my temps stay very low.

EDIT: Forgot to be helpful.

The fin and plate designs, like the one pictured, are very efficient. Size it to be fairly close to the size of your current cooler (area times thickness) and you should not have any problems.

 

well from what the mfg. says and if the price is right and the used cooler is clean
why not ?

 

The one above has 66 sq inches of surface area and is 1.5 inch thick. I can't remember what the stock one is (I threw it out when I broke it for the last time), but I think this one has it beat by a bit. The one in there now is a bit smaller, and a tube design, and it doesn't quite cut it.

Mind giving some details about the one you're using from the V-Rod? What are the dimensions for it?

 

Exact dimensions... Not sure. Its aproximately 1/2 the length, 1/2 the thickness, and maybe 10-20% taller.

The story is, we broke our cooler, and luckily enough, my fiance works for the company that makes those coolers. Her boss offered to take our cooler as an "engineering sample" in exchange for any other one they make. So, she brought the cooler in, they cut it open and did an anlaysis of the heat transfer properties, and gave us back the the tiny little one from the V-Rod.

I asked her to double check the calculations, because I didn't believe that such a small cooler would work, but they were right. The car has a 2nd gen rad and this cooler, and the electric fan almost never comes on. Sooner or later I will get around to getting some pics.