I've got a truck like the Eldorada (HSP Tyrannosaurus, though I've also called it a Redcat Volcano and a Himoto Viper since they're basically the same thing) and I've done a few mods to it. They can be really quite quick! I've done the same header that Eddie is pointing you at, a Team Associated torque pipe, and the direct drive transmission / 13 tooth clutch bell mod. Depending on the tires I'm running at the time, it can run just about as fast as my XTM Mammoth ST (1/8 scale truggy). When I've got it going that fast, it's kind of tough to control! Like Eddie says, it's no joke at that speed.

Personally, I like the way it's set up now: all the above mods, but with buggy "all terrain" style tires (Proline Dirt Hawg). It sits lower to the ground and the tires are much more repsonsive because they're lighter and lower profile, and because they're smaller in diameter the truck accelerates like crazy! I might try a 14 tooth or a 15 tooth clutch bell with these tires, but I also have a 2 speed buggy transmission I want to try. I use it mostly on pavement now and I don't jump it much, so it's kind of a top speed machine right now. It MIGHT get a big block into it, but I still think I can get the VX18 to haul butt.

If this is your first truck and you haven't driven one before, I'd suggest you learn how to drive it first in a nice open field, away from things you can hit. Try setting up some lightweight obstacles and drive your truck between them at top speed to train yourself to miss things. These trucks are pretty fast and responsive, they flip easily and when they flip/hit stuff they can break parts pretty easily. I don't know if you've got C-hub or pillowball suspension on yours, but if you're buying the header & pipe from Eddie, buy some steering knuckles and rear uprights, maybe some lower suspension arms, dogbones, etc. They're cheap and you're probably going to need them if you're jumping & running hard off-road. I also like the aluminium wheel hexes, because you can tighten the wheels down hard and the wheel will still turn freely. Upgrade to sealed bearings if you have bushings at the wheels too.