Got to 100 now die Hatin told me that these racing cars with larger rear ratios & smaller front ratios aren't designed to reach 100 mph.
If the front & rear wheels aren't pulling the same speeds, the mis-matched front & rear ratios will hold the car back, even with a one way diff.
The one way gets overpowered. Only the HPI RS4 RACER 2 & Super Nitro can reach because of the super high & balanced front & rear gear ratios.

So the question that I need answering is....what is the maximum speed you can get these racing kits to go?

XRAY NT1 (Foxy said 75 tops)
Serpent 720 07'
Mugen MTX4
Kyosho V-ONE RRR
XR80