Why did my lipo swell like a balloon?

[Bmr4life]

That sucks if I'm geared to high. On 4s this gearing would get me around 40mph which I thought was ideal for most racers.

So if I want to bash at 50-60mph, what setup would I need?

40c batteries? I'm assuming those are the turnigy nano techs'

Also, my CD is thick as heck right now. Pops wheelies at almost any speed.

Here's a picture of the setup on 4s.