Spent yesterday at the track, with sport mode on I didn't see any water temps over 190 on the temp gauge. Normal driving in sport mode it's about 180. I didn't datalog anything but the gauge matches what I read through OBD2 pretty closely. The radiator has the cooling capability, it's the thermostat setting that's keeping the temps up. There - you have an excuse to go get a tune!

 

Did you happen to check your oil temp while you were out on the track?

I was at WGI for two days this past weekend. I didn't see water temps above normal (215 deg) even with high 80s temps outside. So, ya, I agree the stock radiator seems to have capacity.

However, that doesn't seem to translate to oil temps even though the oil is cooled by the engine coolant. Between Saturday and Sunday I saw about a 20 deg drop in oil temp with about a 20 deg drop in ambient temp, even though the water temp stayed constant.

So I wonder if a tune would do me any good in that department. Well, you know, other than the fun of having another 30 hp or so under the hood.

 

I don't have a scan gauge and I haven't figured out the custom PID to get oil temp over OBD2 so I can't check oil temp. Reducing the coolant temp should help reduce oil temps through the water/oil heat exchanger, but I can't say by how much.

I liked your idea of using the AT version of the radiator, but from looking at realoem and the Bentley manual the AT uses another water/oil heat exchanger for the AT.

Have you looked at the Sneed oil cooler kit?

 

I found the same thing about the AT cooling. Not sure why then there would be a different radiator for cars with the AT. Maybe it has more capacity?

It would seem that you are right about lowering the coolant temperature should lower the oil temp. Just wish someone could confirm that. I would also like to figure out why the oil temp runs so high with the stock system when BMW seems to have gotten the rest of the coolant system right. Seems wrong that they missed on cooling the oil.

Yes I have seen the Sneed system. However, if I remember correctly it is an oil to air cooler. It was hoping to figure something else out so I didn't have to worry about having too low of an oil temp in the winter.

Thanks for the help

 

I found this site for an aftermarket R56 radiator:

http://www.direnza.co.uk/bmw-mini-co...-radiator.html

 

Thanks for posting the link
That looks interesting but is in the UK. Still, I wonder how different it is from an AT radiator?