I would not disconnect it if I were you, but it's your bike.
The oil cooler is there to route the oil to where the air flowing over it can remove heat generated in the engine. This does many things for you. Cooler oil will keep your engine cooler, and a cooler engine will allow for more compression without pre-ignition or detonation. If your oil gets too hot, then it will start to break down and lose its viscosity. When the viscosity goes away, so does your lubricating ability. No matter how much increased volume you gained by removing the cooler, the lower viscosity will accellerate bearing and engine wear, and could lead to bearing failure with subsequent siezing of the engine.
This is just my opinion, but I think you would be better off to leave it in place. Hope this helped.