The stock spur is 46t? What happened to the stock gear?
Edit: I need to read before I post . My best guess is that he bought a used roller and someone might have changed it or he was using something else and found that with the 46T he would get more speed.
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S
Have you tried bigger pinions? It's what I usually do when I need more speed. Right now I have a 17T and if I want more speed I can just add a from 18-30T pinions. For more speed you would need a smaller spur and/or bigger pinions, but keep in mind you will also increase the amount of AMPs.