Hands down Mugen MBX5T with just about any high end .21. I run a V-spec for club and an EB Mods V-Spec for bigger events. I have a RB Mods Ninja on my 5R and I may throw it on the 5T just to see how it is. The truck handles great (on-power steering), responds well to small changes, and is soooooo forgiving. Race buddies are running a variety of motors on them but here goes: 2 guys running JP Modded V-Specs, 1 CEO Power Mods OS .21VG, 1 RB Mods 821, 1 P5X, 1 Radical 621, 1 Hott Mods 21-5.