I have an evod, an aerotank, and an RSBT. I recently built the same coils for each of them. All the coils are 1/16th 2ohm 30 gauge kanthal, and wicked with japanese cotton. The evod and aero tank both have great flavor, but the RSBT has almost no flavor. Its wicking well, no dry hits or anything. There's plenty of vapor, but the flavor just isn't there. What can I tweak to increase the flavor?