exhaust deflecter

Not really, and if it does you will not be able to notice, it will just make more of a mess

Tarant is right. On the revo, the deflector doesn't rob hardly any power that I noticed. It does make it quieter and keeps the gunk off the chassis better with it on though.

Getting a different exhaust will give you more power. The trinity super flow or the traxxas resonator are good pipes. The trinity is supposedly really loud though...