OK you guys, i have been thinking about getting a brushless system for my rustler so what system would be the best and would i need to change the gearing.

This will help alot thanks!

Ps. about how fast will it go thanks

you are better off buying a better truck or upgrade the rustler with bearings first bushing will only slow you down

Brushless will not nessasarly make you go any faster. Depending on what you had in it before, and what brushless motor/system you put in it. A good start would likely be the Novak 5800 motor. If your on a buget the Novak SS system/controler is fine. If you want better, then go for the GTB controler. If you put one of the faster motors in it... you may wind up breaking more parts.

a 5800kv motor should be about as fast as a 15 turn or so... You will have to gear up further then you would with a brushed motor though.

The only real advantages to brushless are... less motor maintainence and more effcient use of electrical power. A good brushed motor can be just as fast as most brushless motors... untill the brushes wear out, or your battery drains.