I don't have any experience on the turbo cars but 1Ms don't have nearly the amount of cooling issues on the track as regular n54s. Several experts have said that oil cooling isn't as much as a problem as water cooling on the N54. I'd go for it for sure if I had an N54. Hell, I might do it on my N52 if it fits. I'm already getting an oil cooler why not the extra radiator.
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here!
| Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors