Number of windings keeping constant the poles
For an AC induction or synchronous motor the speed will be the same the torque will be higher.
For a DC motor speed =
\$V_s -R_a I_a \over k \Phi \$
so as flux increases speed will decrease, torque however will increase.
If you are going to make a small demonstration type of DC motor you are going to get more benefit by making your armature with two coils at right angles. This will give you a motor which runs more reliably and stably. This means your commutator has to have four segments (or pieces of wire).