Yeah it wouldn't hurt anything. All brushed engines life is limited anyway. So eventually the brushes will burn out. And the more power you put into it the faster it'll burn out. I just hate dealing with brushed engines. I'd personally say whenever you get a chance go brushless. The Castle Creation's Phoenix-35 speed controller would be great with a E-Flite brushless 400 engine. About a total of $140-USD depending on where you buy it. By the way I have the Castle Creation's Griffin-40 speed controller also. Good Speed controller for brushed engines.
GoodLuck
