I'm gonna replace my sh engine and have been talking about it in some other forums. Right now I'm trying to decide between the sh.18, the os.18, and the lrp z.18. They all seem like good engines I think the lrp might have the most power but do any of you guys have any insight on what one might be best? 1/10 mamba/tsunami is what its going in and it has the .18vx now. I need more power lol.