[scarletboa]

Better battery packs might help. I have those exact packs for my savage flux and they are very weak. Even my 20c 5000mah turnigy packs blow those smc packs out of the water. I can do standing backflips with any of my batteries, except my smc packs. Also, they puffed on a very light run geared for 45mph on pavement with e-maxx tires.

If you gear higher, you can get the speeds you want, but, you will stress those batteries more and they will likely puff. Hobbycity has some really good, cheap lipos that will give you a noticeable. Boost in sped and torque without even gearing up. Also, if you wanted to gear up, the turnigy batteries would be able to easily handle it. There are some nice 40c hard case packs on hobbycity.com for about $25 each.

If you can't get new batteries, try a 21t pinion. That will boost your top speed without stressing the esc or motor too much, but those batteries might not be able to handle it for too long.

Edit: if money isn't really an issue, try some hyperion packs or some of the new turnigy nano-tech packs. They both have nanotechnology and will last longer than typical lipo batteries and have insane power at the same time. If you decide to go with the hyperion packs, rc-monster has them at a good price.