The turns do refer to how many winds are on the armature, the less winds the faster it will be, so a 27T stock motor is very slow compaired to a 15T mod motor.
In this quest for speed you will end up having to do more maintenace, you will loose alot of run time, and motor rebuilds every couple of runs are necessary with mod motors with brushes.
As suggested get yourself a brushless system. There's nothing to maintain except maybe oiling the bearings so often, and they are more efficient, so runtimes are much better compaired to a brushed motor. Look at www.stormerhobbies.com
they sell the Castle creations sidewinder with 5700kv motor (10T mod equivilant) for $129 that will make you grin from ear to ear. I run this in my T4/B4 and can tell you its more than enough power!