The nitro gv cage does 110 kmh I tested mine with a speed gun if this helps you
the moon buggy averages about 10 miles per hour
It's 2 speed so you're looking at 30mph+ Hopefully you will get in the 40-45 range with enough space and a good tune.
The ´ace maxxam´ 125cc buggy, 12.5hp @ 7500 rpm, weighing 465 pounds, will go (apparently) 38-40mph (or up to 65 kmh).
I've done 45 mph on mine.