Are there any differences in the driver side cooler from an R1 to a non-R1? My searches seemed to point to yes they're identical, but I wanted to be sure. My driver side cooler still works, but its got a nasty dent and overspray and such.

 

from what i have seen on my friends R! when we put on the Series 7 front end is that they look identical. i would think its there for more area and oil capacity to cool the motor some since the FB's and FC's had short yet very wide oil coolers. (they remind me of those small aftermarket I/C's that the 1.8T jettas and Golfs only much shorter in height)

also it could be the idea that mazda wanted to have more oil cooling but did not want to block anymore incoming air to the rad and made the two side intake ducts larger.

but thats from my own assumptions

 

They are identical.