I have the same setup as you.
Castle Creations Mamba Monster Max 2650 and have a new Zippy 5000 Mah 25C lipo and today I spent over 20 minutes doing speed runs up and down the street going full speed doing wheelies and jumping the neighbors skate board ramp. I bet full on racing I would easily do 20 minutes plus.
Losi LST-XXL2E, XMAXX
ARRMA Kraton BLX, Stampede VXL
AE RC10T4 Novak 8.5 brushless, RC8
Losi Micro-T Desert Truck, HPI micro Baja
DJI Phantom 3 Advanced