Here is a good set for Fern Bay Rallcross long reverse, I gave this set to someone and they were getting 1:22's with it. For the short rallycross, set the final ratio to 4.700. and obviously flip the cambers around for the non reversed combos. What it really comes down to, is finding a rhythm on the rallycross tracks. Blackwood has a great rhythm to it. Also, rely less on brakes and get used to sliding to burn off speed.