I tested a few combinations, found BD & Thunder Power motor as the quickest combo (in a Mi4cx)

I ever only used it in one 5min qualifer at a club meet, it was almost as quick as a 17.5 down the straight & after a few oop's moments on the track came from dead last to 2nd in 2min... It was that impressive, it made a couple of jerk off's from another club compliain to the offical body