We'll start with a stock #868
Savage X 4.6. This is our latest powerhouse monster truck, designed for raw, aggressive power and featuring loads of options to beef up the standard Savage X drivetrain and performance. The X 4.6 has a 2.9 horsepower F4.6 engine for huge amounts of power, new red fibre disc brakes to bring it to a fade-free stop FAST, and alloy diff cases for extreme power handling. Being the 'X' type Savage, the truck comes standard with lightweight suspension arms, 4-gear diffs, 3-shoe PTFE clutch, 17mm hex hubs, stronger plastic uprights, dual-stage air filter, new style clutch bells, machined diff bevel gears, stronger skidplates, easily removable bumpers, horizontal-split transmission case, bellcrank servo saver, dual shocks at every corner, primerless 160cc fuel tank and much more...
All this makes the Savage X 4.6 a nimble and powerful monster truck racer, but like any stock machine it can be improved for ultimate racing performance!
How can this be accomplished, you ask? Here's a few things you can ask your local model shop for on your next visit:
#87245 Savage Suspension Conversion Set
- this adds thick upper turnbuckles and super-strong aluminium rear hub carriers, front steering knuckles, front uprights and turnbuckle mounts, plus stainless steel outer hinge pins. You can also adjust the wheelbase at the rear with the included spacers.
#A720 Big Bore Aluminium Shock Set
- with extra oil capacity, these shocks really smooth out the rough stuff, keeping the tyres on the ground for maximum traction and control. These are progressive shocks with 2-stage springs, with ride height clips for super-fast adjustment. You only need one shock per corner with these fitted to the Savage!
#87233 Nubz Conversion Set with 17mm UV Joints
- not only do you get super-tough truggy-style 17mm anodized clamp hex hubs and thick axles, with this setup you get extra-strong universal joint driveshafts and the ultimate HPI monster truck racing tyres: Nubz! Low-profile square pins on race compound rubber and moulded inner foams fitted on aerodynamic dish wheels for a fantastic racing feel on just about every racing track.
#86399 Heavy Duty Heatsink Engine Mount
- strengthening the engine plate while providing extra cooling area to keep the engine at its optimum operating temperature, this is a one-piece, billet-machined chunk of aluminium that is solid, light and extra-cool.
#86138 Polished Aluminium Tuned Pipe
- For more power at the top end and massive head-turning sound, you'll want an aluminium dual-chamber pipe. The standard plastic pipe is dual-chamber as well, but the option pipe looks better and is definitely much louder!
#77127 Heavy Duty Spur Gear 47T
- the stock spur gear is plastic, which is nice and light in weight, but racers using the full power of the F4.6 engine need a bit of extra insurance on the track, and replacing the 47T plastic spur gear with the 47T Heavy Duty steel version is the first step in beefing up the drivetrain.
#77108 Racing Clutch Bell 18T
- the steel spur gears must be used with our Racing Clutch Bells, so for the Savage X 4.6 Racer build we've gone with an 18T clutch bell for a bit extra top speed compared to the stock 17T clutch bell. The Racing Clutch range for the Savage allows you to fit different sizes of clutch bells, from 15 to 20 teeth, so you can choose the best combination for your track needs. The smaller clutch bells give you more acceleration at the cost of top speed, and larger clutch bells will let you hit higher top speeds, but your Savage will be a little slower out of the corners.
#2012 Hump Battery Pack for Receiver
- it just won't do to run out of servo power when you're out on the track, so ideally you'll need a long-life rechargeable pack to power the steering and throttle servos. With the HPI 1200mAh hump pack for the Savage, you'll be able to run several tanks in a row without having to stop to change batteries!
#308 Battery Level Indicator
- when you're running a rechargeable battery pack, you'll want to know how much juice your pack has, and that's where the genius LED Battery Level Indicator comes in. Pull into the pits and peek under the body, and you'll know at a glance exactly how much power you have left, so you can plan a battery swap before you lose all power.
#80587 SF-2 Servo Metal Gear Conversion Set
- most racers have their own preferred type of servo, so they'll swap out the stock SF-2 steering servo with their expensive digital, high-torque, metal-gear servo. However, not everyone has the cash to upgrade right away, so if you're going to race with the standard servo it's a good idea to upgrade it with the Metal Gear Conversion Set.
Finally, to fit the Big Bore shocks properly, get one pack each of Z547 M3x20mm Cap Head Screws and Z224 M3x8mm Washers. You'll need four each of the screws and washers.
Make sure that you are careful when using sharp objects such as the cutting blade and screwdrivers. Children should have adult supervision and guidance.
So we start with the stock Savage X 4.6, with all of its standard beefed-up dimensions and drivetrain parts. It's a great starting point, but let's get building!
Now we'll removed the existing suspension parts and get to work swapping in the new racing suspension set!
There we are, your Savage is stripped down and ready for some alloy action!
Everything ready to assemble
There are all the parts waiting to get fitted. Make sure you have a sharp hobby knife or rotary tool ready for the next part, and read through the instructions first before starting. Some installation steps are different between the Savage and Savage X, so make sure you know what's coming next when you're assembling everything.
Trimming the plastic
The only parts you'll need to trim away on your truck are the areas shown here. Remember that you need to do the same thing front and rear. These parts are clearly shown in the assembly instructions also.
Installing the bearings
Carefully push in the knuckle bearings - if you have to push them in, use a gentle amount of force and push only on the inner metal edge, not the black rubber part.
Assemble the universal dogbones
Because we're installing the Nubz conversion set at the same time, it's best to assemble the universal dogbones at this point. Notice that the cross pins have carefully ground flat spots where the set screw fits. Use a small amount of threadlocking compound on the set screw, and make sure the screw fits against the flat spot of the cross pin (look carefully at the picture!).
Installing the hinge pins
Nearly there! Push the hinge pins in carefully and use your pliers to gently push the e-clips into place.
Rear end hinge pins
At the rear end, the assembly is a little simpler than at the front, except you have the adjustable wheelbase spacers to look out for. A longer wheelbase gives you extra stability on large tracks but it will take more time to turn into a corner, while a shorter wheelbase makes the truck turn in a bit faster at the expense of high-speed stability.
Bolt on the Big Bore bad boys!
And now we get to the Big Bore shocks! They're fully assembled and ready to go right out of the package, all you have to do is bolt them on.
Spacing out the shock ends
Here's where you need those 20mm M3 screws and washers. Because the Big Bore shocks are thicker than the standard shocks and the turnbuckle upper links are also quick thick, if you mount them in the standard position the springs will rub against the upper links and eventually come off the lower spring mount on the shock. To solve this, use a long screw (the Z547 M3x20mm cap head screws are ideal for this) and a washer (Z224 M3x8 washer) to hold the lower shock end in place. The steel screw will resist bending, and the length of the screw allows it to go all the way to the inner shock support on the arm, giving the shock as much support as possible. You can see how much room this simple mod gives the shock spring and upper link!
There we are, nearly complete! Just need to add the wheels...
Ready to go!
With the Nubs securely bolted on, this Savage X 4.6 is ready to RACE! Now you just need to fit on a sleek racing bodyshell like the #7196
Ford F-150 or #7194
Nitro GT-2, or go for a quick and easy pre-painted Nitro GT-1 design like the #7752
black/metallic grey/metallic smoke, #7754
metallic grey/silver/metallic blue or #7753
metallic grey/black/red designs!
Get out there and tear it up! Remember that there are still more parts you can add to the Savage to tune it for any race track you might find. Change the gearing, lighten it up with titanium gear shafts, add the 3-speed transmission, choose different tyres, and beef it up further with stronger outdrives - the options are almost endless!
We hope you've enjoyed this upgrade tutorial. If you want to order the parts used here, just contact your local model shop and ask them to order the HPI part numbers listed at the beginning.