Well… gee.. Savage X wasn’t meant to be a racing truck. If that’s really what you want, my honest words, in spite of the fact of owning a Savage X which I also modify quite a bit, are that for speed… save that money upgrading and just get a Traxxas Revo 3.3. The Revo may break a lil easier but it’s lighter and quick. Look on the bright side, if you spent the $400 you would have spent on mods on a Revo instead, you’d have 2 trucks! Ain’t that great? One to bash, and one to bash +race.
OK.. that’s being a little irritating. I shall answer your questions more directly, and I’ll do so all at once. Engine mods… other than a supercharger, which I’ll talk about shortly, are limited. You might wanna look at a different-shaped tuned pipe, with some knowledge from my recent posts on the varying functions of tuned pipes based on shape. About supercharging, that definitely works, but I think it’s better saved for road cars. Off road is just too much load on your engine when handling rough terrain, and the added strain via a supercharger such as the one by RB innovations is gonna cause your engine to break down alot faster. You might be better forking out a lil more money for a good motor (engine).
What’s the “fastest engine for savage x” then? There’s one engine out there that I’d call the fastest. Its simply getting the most powerful engine you can get, the one which dishes out the most horsepower and hoping that can fit in your chassis. I know for a fact a 5.9cc, or .36 engine will fit in.. but you might experiment with a 7.5cc(.46) engine and tell me if that works out. The Savage XL already uses the 5.9 cc engine. I’m not saying you have to get the HPI Nitrostar 5.9… because it isn’t the most powerful engine out there.
I suppose price is a concern.. So I actually suggest you start looking out for SH Engines which are from Taiwan. They are already on cars by Redcat Racing as well as ExceedRC. For a fairly low price, you can get a solid 5-6 horsepower engine for your Savage X. Then you’ll just have to play around with gear ratios after that, i.e. bigger spur gear or smaller clutch bell, for a higher top speed as your new engine will readily support it’s new speed.
I’ll be doing a review on SH Engines soon. Look out for that!