I had one of these and powered it with a .46AX and it was a screamer! Very fast. I think the secret to this plane is to keep it light. You will hear many tell you to put a larger engine on it then add even more weight to bring the CG back in range. Am telling you from experience that the plane needs nothing more than a .46AX or maybe a hot .50 sized engine. Not every plane has to have "unlimited vertical" to perform!