9XL on 16 cells..what sort of performance?

[Rtsbasic]

Gustav, nice one, thanks for explaining that. So if I gear it 20/51 (with the 3.3:1 diff's) it should be around 14.5 FDR, which on 16 cells will give me approx 40mph top speed and hopefully still 10-15 mins of runtime on 3700's. Does this sound reasonable from this setup?

[Gustav]

Sounds reasonable to me,i've been using this speed calculator that Brian G made http://www.scriptasylum.com/rc_speed.html.
I normally just put in the nominal voltage and the non-ballooning tyre size (on the basis that they cancel each other out a bit) to get a rough guestimate.