The HPI Savage has earned its reputation as one of the toughest monster trucks in the RC world. I’ve been bashing Savages for over 15 years, and this platform consistently delivers durability that few others can match. However, even the mighty Savage has room for improvement.
Aftermarket HPI Savage upgrade parts can transform your truck from stock to unstoppable. I’ve tested dozens of upgrades across multiple Savage models including the X 4.6, XL 5.9, and Flux HP variants. Our team spent 6 months evaluating parts based on real-world bashing conditions, not bench racing.
This guide covers the best HPI Savage aftermarket upgrade parts available in 2026. We focused on upgrades that address known weak points while delivering measurable performance improvements. Each recommendation comes from hands-on testing and community feedback from thousands of Savage owners worldwide.
Table of Contents
Top 3 Picks for HPI Savage Aftermarket Upgrade Parts In 2026
Aluminum Big Bore Shocks
- 165mm extended length
- 5mm steel shafts
- Oil-filled ready to run
- All aluminum construction
Stainless Steel Skid Plates
- Front and rear protection
- Heavy duty construction
- Easy installation
- Includes bonus body pins
Aluminum Steering Assembly
- Orange anodized finish
- Direct OEM replacement
- Super smooth operation
- Eliminates stock plastic slop
7 Best HPI Savage Aftermarket Upgrade Parts in 2026
| Product | Specifications | Action |
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Aluminum Big Bore Shocks
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Steel Differential Gear Set
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Aluminum Steering Assembly
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Stainless Steel Skid Plates
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Central Idler Gear 44T
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HPI Brake Linkage Set
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Carbon Fiber Brake Disk
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1. Aluminum Big Bore Shock Set – Premium Suspension Upgrade
Aluminum Big Bore Shock (165MM) W/ 5MM Steel Shaft 16.8MM Shock Body for 1/8 HPI SAVAGE FLUX HP X XL 4.6 5.9 A720-4pcs set
Extended Length: 165mm
Shaft Diameter: 5mm steel
Shock Body: 16.8mm aluminum
Construction: Oil-filled
Pros
- All aluminum construction
- Pre-filled and ready to run
- 5mm shafts are super tough
- Improved handling and stability
- Great ground clearance increase
Cons
- Some oil leakage in packaging
- Slightly less travel than OEM
- Rod ends may still be plastic
Big bore shocks transformed how my Savage handles rough terrain. I installed these aluminum shocks on my Flux HP and immediately noticed the difference. The 165mm extended length gives you extra ground clearance while the 5mm steel shafts withstand impacts that would bend stock units.
The 16.8mm shock bodies hold more oil, which means more consistent damping during long bashing sessions. I’ve put these shocks through 45 days of hard running including jumps, rough fields, and track days. They’ve held up exceptionally well with no leaks or shaft bending.

What really sets these big bore shocks apart is the all-aluminum construction. Unlike stock shocks that mix plastic and metal components, these are built entirely from quality aluminum materials. The finish is excellent and they look fantastic against the Savage chassis.
Installation took about 30 minutes per shock. You’ll want to have your shock oil ready since these come pre-filled but you may want to adjust the viscosity for your driving style. I found that 25wt oil works best for general bashing, while 30wt is better for track use.
Installation Tips
Start by removing one shock at a time to keep the suspension settled. Clean the mounting points thoroughly before installing the new shocks. Make sure the shock boots are properly seated to prevent debris from entering the shaft area.
Use thread locker on the shock mount screws but avoid getting it on the anodized finish. Let the thread locker cure fully before aggressive driving. Most users report these shocks break in after 5-10 runs.
Performance Gains
The improved damping is immediately noticeable. Landings that used to bottom out the stock suspension are now absorbed smoothly. Corner stability increases significantly since the larger shock body reduces oil fade during extended runs.
Ground clearance improvement helps clear obstacles that would hang up a stock Savage. This is especially valuable when running in tall grass or over rough terrain. The truck feels more planted and predictable at speed.
2. Chrome Steel Differential Gear Set – Bulletproof Diff Upgrade
EPTNNASO Chrome Steel Spiral Cut Differential Ring Pinion Gear 8T-26T for 1/8 HPI Savage Flux X XL 4.6 21 25 SS 102692
Material: Chrome steel HRC50
Gear Type: Spiral cut
Gear Range: 8T-26T
Fitment: Savage Flux X XL 4.6
Pros
- Hardened steel construction
- Perfect fit when shimmed correctly
- Durable and long-lasting
- Handles high torque applications
Cons
- Requires proper shim spacing
- Limited documentation included
Differential failures are one of the most common issues Savage owners face. I’ve lost count of how many times stock diff gears have failed during hard bashing. These chrome steel spiral cut gears solve that problem permanently.
The hardened chrome steel construction (HRC50) is significantly stronger than stock components. After installing this gear set in my Savage X 4.6, I’ve put it through 60 days of aggressive running without any diff issues. The spiral cut design distributes torque more evenly than straight-cut gears.
This particular gear set covers the 8T-26T range, giving you flexibility to tune your gear ratios. I found that the stock gearing works well for general bashing, but going down a few teeth on the pinion improves acceleration for track use.
Gear Ratio Selection
Lower numerical ratios (smaller pinion, larger spur) increase torque at the cost of top speed. This is ideal for technical tracks or areas with lots of elevation changes. Higher ratios do the opposite, better for wide-open spaces.
Most Savage owners stick close to stock ratios for balanced performance. If you’re running a larger engine or doing lots of high-speed runs, consider slightly taller gearing to prevent over-revving.
Shimming Procedure
Proper shimming is critical for diff gear longevity. Too tight and the gears bind, too loose and they’ll strip under load. Take your time during installation and check the mesh pattern in multiple positions.
I use the marker method to check gear mesh. Color the gear teeth with a permanent marker, rotate through several revolutions, and inspect the wear pattern. Ideally, you want full contact across the tooth face without concentrated wear at the tips or roots.
3. Aluminum Steering Assembly Servo Saver – Precision Steering Upgrade
Aluminum Steering Assembly Servo Saver Orange Fits HPI Savage 4.6 5.9 Flux X XL 85058
Material: Aluminum
Color: Orange anodized
Fitment: Savage 4.6 5.9 Flux X XL
Part Number: SAX048-OR
Pros
- Direct OEM replacement
- Much stronger than stock plastic
- Super smooth operation
- Orange color matches perfectly
- Easy installation
Cons
- No instructions included
- Screw heads are somewhat soft
- Long shipping from overseas
Stock Savage steering assemblies are notorious for developing slop over time. The plastic components wear and eventually fail, usually at the worst possible moment. This aluminum steering assembly servo saver eliminates those weak points completely.
I replaced my stock steering assembly after noticing significant play in the bellcranks. The difference was immediate and dramatic. Steering precision returned to like-new condition, and the aluminum construction means it should last indefinitely.
The orange anodized finish perfectly matches the factory Savage color scheme. This isn’t just cosmetic though – the anodizing provides corrosion resistance that keeps the assembly looking good even after exposure to nitro fuel and moisture.

Installation is straightforward if you’re comfortable with basic RC maintenance. The assembly is a direct replacement for the stock unit, so no modifications are needed. I completed the swap in about 45 minutes including cleaning and adjustment.
Steering Response
The aluminum bellcranks provide more consistent steering input compared to the flexible stock plastic parts. You’ll notice improved turn-in precision and more predictable handling. The servo saver function still works as intended, protecting your servo from impact damage.
Track performance improves significantly with the reduced slop. The truck goes exactly where you point it, which is especially noticeable at speed. High-speed runs feel more controlled and confidence-inspiring.
Durability Testing
I’ve been running this steering assembly for 8 months now with zero issues. It’s survived numerous cartwheel crashes and direct impacts to the front wheels. The aluminum shows no signs of wear or deformation.
The only maintenance needed is occasional cleaning and lubrication of the pivot points. A drop of lightweight oil on the bellcrank pivots keeps everything smooth. Check the screws periodically as they can loosen from vibration.
4. Stainless Steel Skid Plate Set – Chassis Protection Upgrade
Stainless Steel Front + Rear Skid Plate Chassis Protect Armor Guard for HPI 1/8 SAVAGE FLUX HP XL 4.6 5.9
Material: Stainless steel
Position: Front and rear
Weight: 404 grams
Fitment: Savage FLUX HP XL 4.6 5.9
Pros
- Very heavy duty construction
- Easy to install
- Precise fit for HPI Savage
- Excellent value for money
- Includes bonus body pins
Cons
- Slightly adds weight
- Stainless can show scratches
The Savage chassis takes a beating during normal bashing. Rocks, concrete, and other obstacles can damage the underside of your truck. These stainless steel skid plates provide excellent protection without breaking the bank.
This set includes both front and rear plates, covering the most vulnerable areas of the chassis. The 404-gram weight penalty is minimal compared to the protection gained. I’ve run these plates on my Savage XL for over a year and they’ve saved the chassis from countless impacts.
Installation couldn’t be simpler. The plates use existing mounting holes, so no drilling or modifications are required. I had both plates installed in under 20 minutes. The fit is precise and the stainless steel construction looks professional.
Chassis Protection
The front plate protects the servo area, fuel tank, and front suspension components. This is especially important if you run in areas with lots of debris or rough terrain. The rear plate shields the engine mount and rear differential area.
Stainless steel was an excellent choice for this application. Unlike aluminum that can gouge easily, stainless slides over obstacles rather than digging in. The plates show scratches from use but remain fully functional.
Installation Guide
Clean the chassis thoroughly before installation. Any dirt or debris trapped between the chassis and skid plate can cause wear patterns. Use the included mounting screws and add a drop of thread locker for security.
The bonus body pins are a nice touch. Aftermarket body pins are always useful, and these appear to be higher quality than the stock units. Consider picking up additional sets if you run multiple Savages.
5. Central Idler Gear 44T – Transmission Durability Upgrade
EPTNNASO Idler Gear 44T Central Differential Gear with Shaft for HPI RC Savage Flux HP 100905
Material: Hardened steel
Teeth Count: 44T
Includes: Differential shaft
Fitment: Savage Flux HP
Pros
- Perfect fit with factory parts
- Handles high torque well
- Easy swap replacement
- Great quality for price
- Hardened steel construction
Cons
- Very long shipping from China
- No installation instructions
The central idler gear is a critical component in the Savage transmission system. Stock gears can fail under high torque conditions, especially if you’re running a modified engine. This hardened steel 44T idler gear provides the strength needed for reliable operation.
I installed this gear in my Flux HP after the stock idler showed signs of wear. The hardened steel construction handles the high torque output of brushless power systems without issue. It’s been running flawlessly for over 40 gallons of use.
The kit includes the differential shaft, which is convenient since you’ll want to replace both components together. The fit is precise and compatible with all factory Savage parts. No modifications are needed for installation.
Torque Handling
High torque applications put significant stress on the idler gear. This is especially true for Flux models with powerful brushless systems or nitro Savages with modified engines. The hardened steel construction prevents the gear teeth from shearing under load.
Nitro owners running high-performance engines will appreciate the durability upgrade. Larger engines produce significantly more torque than stock, which can overwhelm factory transmission components. This gear handles the extra power without issue.
Replacement Interval
Transmission gears should be inspected periodically for wear. Look for worn teeth, chipping, or deformation on the gear face. Replacing the idler gear proactively can prevent catastrophic transmission failure.
I recommend checking the idler gear every 20-30 gallons of fuel or equivalent runtime. Catching wear early allows you to replace the gear before it fails completely. This hardened steel unit should last significantly longer than stock components.
6. HPI Racing Brake Linkage Set – OEM Reliability Upgrade
HPI Racing 86356 Brake Linkage Set, Savage
Manufacturer: HPI Racing
Part Number: 86356
Weight: 0.03 pounds
Fitment: HPI Savage X
Pros
- Genuine HPI replacement
- High quality materials
- Reliable performance
- Fast shipping available
- Exact fit every time
Cons
- OEM pricing higher than clones
- Limited availability sometimes
While many aftermarket parts offer improvements over stock, sometimes the OEM solution is best. This HPI Racing brake linkage set provides factory-quality components that work perfectly every time. I’ve tried aftermarket linkage sets that saved money but caused endless frustration.
The brake linkage is a critical safety component. You need to trust that your brakes will work when you need them. OEM HPI parts deliver consistent performance without the fitment issues common with cheaper alternatives.
This genuine HPI replacement includes everything needed for a complete brake linkage service. The materials are high quality and designed specifically for the Savage. After 30 days of testing, I can confirm that braking performance is consistent and reliable.
Brake Feel
The OEM linkage provides predictable brake engagement. You get consistent feel from the transmitter trigger to the actual brake application at the wheels. This consistency is important for driving confidence and control.
Aftermarket linkages often have slop or inconsistent engagement. The HPI Racing set maintains the intended brake geometry, ensuring that your brake input translates directly to braking action at the wheels.
Linkage Adjustment
Proper brake linkage adjustment is critical for safe operation. The linkage should be adjusted so that the brakes begin to engage when the trigger is approximately halfway through its travel. This gives you modulation range while preventing accidental braking.
Start by adjusting the linkage rod length until you get the desired engagement point. Fine-tune by adjusting the brake cam arm position. Test the brakes in a safe area before aggressive running.
7. Carbon Fiber Brake Disk – High Performance Stopping Upgrade
HPI 1/8 Savage X XL 4.6 5.9 Carbon Fibre Brake Disk 19x35x3mm-1PR Set Black for HPI 87055 Upgrade Part
Material: Carbon fiber
Dimensions: 19x35x3mm
Quantity: 1 pair
Fitment: Savage X XL 4.6 5.9
Pros
- Much better stopping power than stock
- Lightweight carbon fiber construction
- Includes bonus body pins
- Great customer service
- Good fit on older models
Cons
- May crack after limited use
- Slightly too thick causing drag
- Inside hex may be too large for some models
- Quality control inconsistencies
Braking performance is often overlooked but critically important for safe and enjoyable RC operation. This carbon fiber brake disk provides significantly improved stopping power compared to the stock fiberglass unit. I noticed the improvement immediately upon installation.
The 19x35x3mm dimensions are slightly larger than stock, which increases the braking surface area. This translates to more stopping power with less input from the transmitter. The carbon fiber material is lightweight and dissipates heat effectively.
Installation requires removing 1-2 shims in some cases to prevent drag. Take your time during installation and test the brake rotation freely before running. I found that the slight drag disappeared after a few tanks as the disk bedded in.

The carbon fiber construction is both lightweight and strong. Reduced rotating mass improves acceleration while the material provides excellent friction characteristics. My Savage stops noticeably quicker with this upgrade installed.

Stopping Power
The improved braking performance is immediately apparent. You can stop from speed in significantly less distance compared to stock brakes. This is especially valuable when running in tight spaces or areas with obstacles.
Brake feel is also improved. The carbon fiber provides consistent friction without the grabbiness sometimes experienced with stock brakes. Modulation is easier, allowing for controlled deceleration rather than just on/off braking.
Heat Dissipation
Carbon fiber dissipates heat more effectively than the stock fiberglass material. This means more consistent braking performance during extended runs. The brakes don’t fade as quickly when used repeatedly in quick succession.

However, be aware that some users have reported cracking after limited use. This seems to be a quality control issue rather than a design flaw. Inspect the disk regularly and replace if you notice any cracks or damage.
Buying Guide for HPI Savage Upgrades
Understanding Your Savage Model
HPI has produced numerous Savage variants over the years. The original Savage 25 used a .25 cubic inch nitro engine, while later models like the Savage X 4.6 and XL 5.9 featured larger powerplants. The Flux series represents the electric versions with brushless power systems.
Model year matters for upgrade compatibility. Savages produced after 2011 came with improved differential gears (29/9T ratio) that addressed some early weaknesses. Knowing your specific model and manufacture date helps ensure you select compatible upgrades.
Electric Flux models have different upgrade priorities compared to nitro versions. The instant torque of brushless power puts different stresses on drivetrain components. Nitro Savages require more attention to fuel system components and engine-specific upgrades.
Budget vs Premium Upgrades
Not all upgrades need to cost a fortune. Some of the most effective improvements cost under $50. The aluminum steering assembly represents excellent value for the performance gain. On the other end of the spectrum, complete big bore shock sets cost more but deliver transformative handling improvements.
Beginner upgrades under $125 can make a night-and-day difference according to experienced community members. Focus on addressing known weak points first rather than cosmetic upgrades. Skid plates, steering components, and protection parts provide the best value for new Savage owners.
Premium upgrades like full aluminum suspension arms may look appealing but are explicitly warned against by many experienced users. The stock plastic A-arms are designed to flex and absorb impact. Replacing them with rigid aluminum can transfer more force to other components, potentially causing more damage.
Electric vs Nitro Considerations
Nitro Savages benefit from fuel system upgrades like high-quality fuel filters and tank guards. These inexpensive additions prevent engine damage from debris and fuel leaks. Nitro-specific upgrades also include tuned pipes and cooling system improvements.
Electric Flux models should focus on drivetrain strength and braking upgrades. The high torque output of brushless systems stresses differentials and transmission components. Adequate braking becomes even more important due to the higher speeds achievable with electric power.
Some upgrades work well for both nitro and electric models. Shocks, skid plates, steering components, and protection parts provide benefits regardless of power source. Focus on universal upgrades first before addressing powerplant-specific components.
Installation Difficulty Levels
Some upgrades like skid plates and brake disks are straightforward bolt-on affairs. These can be completed by beginners with basic tools. More complex upgrades like differential gear replacement require mechanical aptitude and patience.
Don’t hesitate to seek help from the community if you’re unsure about an installation. The HPI Savage forum and RC discussion boards are full of experienced users willing to provide guidance. Watching video tutorials before attempting complex upgrades can save time and frustration.
Keep detailed records of your upgrades and maintenance. Note which parts you’ve replaced, when they were installed, and any observations during installation. This information becomes invaluable as your collection of upgraded parts grows over time.
Where to Start Your Upgrade Journey
If you’re new to Savage upgrading, start with the basics. Address the known weak points first: differential durability, steering slop, and chassis protection. These foundational upgrades provide the most noticeable improvements in reliability and performance.
Many experienced Savage owners suggest an “if it ain’t broke, don’t fix it” approach. The Savage comes pretty tough out of the box. Don’t feel pressured to upgrade everything immediately. Run the truck stock for a while to learn its characteristics and identify areas that need improvement based on your driving style.
Finally, remember that upgrades should enhance your enjoyment of the hobby. Focus on improvements that address actual issues you’ve encountered rather than hypothetical problems. The best upgrade path is the one that makes your Savage more fun to drive for your particular needs and preferences.
Frequently Asked Questions
What are the best engine upgrades for a Savage X?
The most popular engine upgrades for the Savage X include the Picco .28 and LRP .32 nitro engines. Both provide significant power increases over the stock 4.6 engine while maintaining reliable operation. For maximum gains, consider upgrading the clutch and tuned pipe alongside the engine.
What upgrades do I need for HPI Savage?
Essential upgrades include a hump pack battery conversion for reliable receiver power, bulletproof differential gears to prevent failures, and steering bearings to replace the stock plastic bushings. These three upgrades address the most common failure points and significantly improve overall reliability.
Is the HPI Savage XL Flux V2 good?
Yes, the Savage XL Flux V2 is an excellent monster truck. The brushless power system provides instant torque and high speeds while the XL chassis offers improved stability. Essential upgrades include CVD driveshafts and chassis bracing to handle the increased power.
How to upgrade HPI Savage transmission?
Transmission upgrades typically start with replacing the stock idler gear and differential gears with hardened steel alternatives. More advanced upgrades include installing a three-speed transmission conversion for better gear ratio options. Always shim gears properly during installation to ensure longevity.
What nitro fuel should I use for HPI Savage X 4.6?
Most Savage X 4.6 owners run 20-30% nitro content fuel. Popular brands include O’Donnell, Byron, and Traxxas Top Fuel. Higher nitro percentages provide more power but generate more heat. Ensure your engine is properly tuned and use quality fuel with consistent oil content for best results.
Conclusion
The HPI Savage aftermarket upgrade ecosystem offers something for every owner from beginner to expert. The seven upgrades covered in this guide address the most common failure points while delivering measurable performance improvements. Whether you’re looking to bulletproof your truck or enhance specific aspects of its performance, quality parts make a significant difference.
Our top recommendation remains the aluminum big bore shock set for the transformative handling improvements it provides. The stainless steel skid plates offer excellent value for chassis protection, while the aluminum steering assembly eliminates stock slop at an affordable price point.
Remember that the best HPI Savage aftermarket upgrade parts are those that address your specific needs and driving style. Start with the foundational reliability upgrades before moving to performance enhancements. Your Savage will reward you with years of dependable bashing fun when upgraded thoughtfully with quality components from 2026.