Try the prop from WattAge's J-3 Cub. It is 3 x 2, compared to the stock 4 x 4.75. It works great with my Direct 280 and Acro280BB motor. It fits tight on the shaft, spins like a ducted fan and makes lots of power.

But I've seen the wing on the Split 280. You'll fold it in half if you get it up to the speeds it gives my Direct 280 flying wing. But that's the way it goes when you feel the need for speed.

SavoirFaire