Team Associated RC10 B7 - the best 1/10th off road car? How to install the electrics 

Add the side foams to your battery tray. If you dont, the battery will move around too much in the locator brackets, and one good wall hit, or tumble, and the leading finger tab of the locator bracket, will snap off. This problem seems to become more of an issue if you have a battery with a curved corner, which moves the weight further to the tip of the finger. By adding the side foams, this will effectively add some resistance to the fore and aft movement of the battery, and significantly reduce the likelihood of that battery locator bracket finger failing. In regards to the brackets themselves. I would also recommend taking them off the car, flipping them over, and filling the underside cavity with CA Glue. Will take a few applications, and i highly recommend using some kicker/activator to speed up the curing process. But keep adding a dab of CA glue until the cavity is over full. Then take it and lay out some finer grit sand paper, and sand the bottom flat, effectively making it a solid piece. This helps tremendously with the durability of the part, and i havent broken one yet. Also of note, with regards to your servo mount...any B6.3/6.4 servo mount will fit up without issue. So if you are not fond of the B7 plastic mount, any of the existing aluminum/carbon options are a direct bolt in.

Which hobbywing esc do you use? Pro. Gs3, Elite??? Im looking for an esc and im not sure what to get, I plan to race 17.5

Which 17.5 motors do yall recommend?

That fan would surely drain the battery if you don't un plug it