ORIGINAL: critterhunter
If you guys do a search in this forum for "Bullet Proof That Bird!" you'll find some of my mods for the Challenger/Extreme. Also, I fly 3300ma cells in the Extreme. A 7 cell pack makes no difference in COG on the Challenger or Extreme in my experience versus the six cell. The extra horsepower kind'a makes up for the weight.
Where did you get the 7 cell 3300 mah pack for the extreme?
BB