Do they make a 49 tooth spur gear for them? Is the transmission the same as the tsunami I think it is. If so I have only ever seen the 42 tooth spur gear but I did do a mod on mine to put a 52 tooth spur gear from hpi in and with the sh18 14/52 gearing 2.2 dirt hawg tires I was still getting 40 mph out if it with tons of low end power. Mind you I did some porting on the sh but still.

If you want even more power then the sh18 has get the os cvrx 18 there really cheap and have more power then the sh18.