MGM 80 and a Feigao 6s

Im thinking about running this setup in my tc4 and my t4. What does everyone think? I Have a need for speed, I want to do about 40ish with the t4, and at least 40 with the tc4. Currently i run a 9x2 in both cars, the t4 does 40 with that, but Its to hard on the motors.

Any feedback would be appreciated!

Oh, How long would my runtime be? I hear these are power hogs, thats fine but I do not want 20 second run times... I get near 10-15 min now.

Note, ill be running Sanyo 3600 1.85+ batteries, sometimes closer to 1.20V batteries.