Already saw your conversion in a other forum. Very inspirational. High Voltage for sure is the right way to get an efficient and powerfull electric setup.
Although i am "only" runnig 10s1p A123 (33V) in a buggy geared for 67 km/h top speed i see similiar numbers with my eagletree logger running a Neu 1512/1Y (1400kv).
Runtime with 2300mAh is between 13-17 minutes. Average Amp draw is around 10A. Average Watts are between 280-350 Watt. Subtracting your short breaks your average Watts and amperage should be in the same region.
A video of your buggy would be very interesting.
i posted 2 videos with eagletree data inserts of my setup in
this thread.
And lutach is coming up with a very interesting setup (10s) too.