Arrma Limitless Spool Upgrade for Max Traction and Acceleration

Introducing the Arrma Limitless RC Car

The Arrma Limitless is an impressive 1/7 scale RC car that has been taking the RC world by storm since its release in 2019. With its unique wheelie bar design and ultra-durable components, the Limitless was built for speed and power right out of the box.

Arrma designed the Limitless for maximum durability and insane top speeds. Its oversized drivetrain can handle 6S LiPo power right away with minimal upgrades needed. And with the long wheelbase paired with a wide stance, the Limitless has unbeatable stability even at speeds over 60 mph.

High Speed, High Power Design

At the heart of the Limitless is a beefy drivetrain capable of handling the extreme power needed for top speeds over 60 mph. It starts with an oversized 1520KV motor that can handle up to 6S LiPo batteries without any issues. This amount of power requires robust drivetrain parts to handle the forces involved.

The differentials, driveshafts, and suspension arms are all upgraded from the standard 1/7 Arrma vehicles. Arrma developed special composite materials and designs to improve durability for the Limitless' insane power output. Even the wheel hexes were upgraded to 12mm to provide more surface area for the wheel nut contact.

Unique Wheelie Bar Design

With the extreme power and torque of the Limitless, keeping the front wheels on the ground was a major design challenge. Arrma solved this problem with an innovative wheelie bar system.

The wheelie bars use small wheels mounted behind the rear wheels on an adjustable rail system. This lets you dial in the perfect height to prevent accidental wheelies during acceleration. It also helps keep the limitless stable at high speed by preventing aerodynamic lift on the front end.

Upgrading the Arrma Limitless Drivetrain

While the Arrma Limitless is an incredible RC car right out of the box, there are a few areas that enthusiasts like to upgrade for even greater durability and performance.

Upgrading the Spur Gear

One common upgrade is switching out the stock plastic spur gear for a high quality steel or titanium spur gear. The amount of torque sent through the spur gear makes it prone to stripping if you run high power setups.

An upgraded metal spur gear improves durability and can also increase efficiency slightly. Popular options are the Hot Racing steel spur gears or the more expensive titanium options from Yeah Racing.

Spool Differential Upgrade

The differentials are also commonly upgraded in the Limitless drivetrain. For maximum traction and explosive acceleration, switching to a spool is a great option.

A spool locks the rear wheels so they spin at the exact same speed. This maximizes the traction off the line by sending equal power to both wheels. The increased acceleration makes the Limitless launch even harder off the starting line.

Some popular spool options are the Yeah Racing V2 Torque Spool and the Hot Racing Torque Spool. These direct replacements bolt right into the rear differential housing for a quick performance upgrade.

The Hot Racing SLR Limitless Spool

One of the best spool options on the market specifically designed for the Limitless is the Hot Racing SLR Limitless Spool.

Durable 7075 Aluminum Construction

This spool is precision CNC machined from 7075 aluminum for maximum strength in a lightweight package. The ribs in the center section help maximize strength while keeping rotating mass low.

7075 aluminum is commonly used in high performance racing applications because of its strength to weight ratio. This makes it perfect for standing up to the extreme power of the Limitless drivetrain.

Long-Lasting Steel Hardware

The Hot Racing spool uses only proper high-grade steel hardware instead of soft screws. Lower quality screws can quickly shear off from the insane torque of a Limitless 6S setup.

The improved hardware ensures you won't have any loose or damaged bolts even after long runs at full throttle. The steel construction also saves weight over titanium hardware while providing similar strength.

Precise Manufacturing Tolerances

With a spool upgrade, precision tolerances are critical to avoid any drivetrain binding. The Hot Racing spool is CNC machined to ultra tight tolerances for a perfect fit.

This prevents any uneven torque delivery between the wheels which could cause handling issues. The precision fit also minimizes stress on drivetrain components by ensuring smooth operation.

Direct Bolt-On Installation

For convenience, the Hot Racing spool is a direct replacement for the stock differential with no modifications necessary. It bolts right into place within a few minutes using only basic tools.

The streamlined installation lets you upgrade to a spool on race day if needed. Dialing in more traction only takes a few minutes in the pits without any major disassembly required.

Conclusion

Upgrading to a high quality spool like the Hot Racing SLR version is one of the best ways to maximize traction and acceleration for your Limitless RC car. With its durable construction and precision engineering, it's built to stand up to the punishment of high power 6S LiPo setups.

Installing this simple bolt-on upgrade takes just a few minutes in the pits. So you can easily swap it to get maximum traction tuned perfectly for current track conditions.

FAQs

What is a spool?

A spool is a locked differential that forces both rear wheels to spin at the same speed. This maximizes traction compared to a standard open differential.

Why upgrade to a spool in the Limitless?

A spool provides better acceleration and traction off the line. This helps maximize the Limitless' speed and power potential for things like speed runs and racing.

Is a spool good for all conditions?

No, a spool can reduce handling and control in slippery conditions or on loose surfaces. It's best for high traction situations like racetracks.

What parts do I need for the spool upgrade?

You just need the spool itself, which replaces the rear differential. No other parts are required for this direct bolt-on upgrade.

Will a spool put more stress on the drivetrain?

Yes, a spool locks the rear wheels together so there is more strain during turning. Make sure to check diffs and driveshafts more frequently when running a spool.