If you want more speed and less maintenance, then you need to hop-up your SC18 with a Brushless Motor and ESC. A Brushless Motor can take your stock SC18 top speed from about 17-18 mph all the way to 30-40 mph+. Here are some quality Micro Brushless Motor/ESC Combos that will dramatically increase the speed of your SC18 and provide compatibility with LiPo batteries.
Note: The SC18 stock ESC is Brushless ready, but if you plan to upgrade to LiPo batteries you will need a new ESC that has LiPo cutoff. If you do not want to use LiPo batteries with your SC18, you should purchase the motor separately. However, we always recommend the use of LiPo batteries with Brushless systems. See SC18 LiPo Battery Upgrade for more info.
Our SC18 Brushless Motor/ESC Recommendation
Novak Micro Brushless System - This is the one of the better ESC/Motor Combo that will give your SC18 the brushless power you want without breaking the bank.
Choosing the right Motor kV
Any motor that falls in the 5400kV - 6800kV range will probably be right choice for most of you (speeds up to 40 mph with 6800kV). If you are not using LiPo batteries, choose the lower kV models (4200kV - 5000kV). If you choose the 8000kV or higher, be aware that higher speeds and more power can often complicate and increase maintenance of your SC18.
Remember to get your LiPo batteries, too. LiPo's will give you even more power and speed. Running a Brushless Motor without a LiPo battery can significantly reduce your runtimes. See SC18 LiPo Battery Upgrade for more info.