got advice for replacement of my .15FE - it is starting to get boring in my HPI nitro 2. Want a new motor. Need specific engine replacement ideas, and why you are recommending. Budget is about $150. Was recommended o.s. CVR and HPI's 12ss engine as well. are they better than my current motor? I currently get to between 36 and 40 mph on the back-straightaway at my track, with a two speed and exhaust system. REALISTICALLY SPEAKING - how much faster will one of these engines allow me to go on this straight-away??