ARC A11 Build Tips & Tricks by Enrico Jung

After a busy period of racing and travelling, I finally had the time to build my first production ARC A11 kit and I want to share some valuable build tips and tricks with you. This is not just about assembling a kit, it’s about building it the right way.

Spool Assembly

We start with the spool but there isn’t much to say here. No additional preparation is needed, simply assemble it according to the manual and the first step is done.

I use Team Titan screws to reduce weight, and I secure the spool outdrive screw with threadlock to ensure maximum reliability.

Differential

Next up is the differential. I’m running 6k diff oil for a balanced and consistent performance. For the gears, I use 1000 grit sandpaper to lightly prepare the surfaces, ensuring a smoother operation and improved durability.

Apply a drop of oil or o-ring grease to lubricate the o-rings.

Gear Preparation

Here you can see how I prepared the gears. I remove any remaining production mould residue with a knife. I only sand the backside of the larger gears using 1000 grit sandpaper. This step is not necessary for the smaller gears.

Mid Pulley

Next is the mid pulley and not much to mention here. Just assemble it according to the manual.

I also use Team Titan screws here to save as much weight as possible.

Recommended Gear Ratios

This is a guide of what I normally use.

Stock:

• 5.0 — 92/35
• 4.5 — 90/38
• 4.0 — 100/47
• 3.8 — 90/45

Modified:

• 7.4 — 105/27
• 7.1 — 105/28

Lower Arm Assembly

Next is the assembly of the new wishbones.

Make sure everything moves freely without any binding, as this is essential for consistent suspension performance. Take your time here to ensure a smooth and precise fit.

With the Team Titan pliers (#15008), the assembly becomes very easy and precise.

 The kit also includes a plastic ring to compensate for the main tolerance difference, ensuring a perfect fit during installation.

Lower Arm Shock Mounts

For the shock mounting on the wishbone, there is an optional aluminum version available.

It’s important to note that this has a significant impact on the car’s handling. I’ve tested both options multiple times and found that, especially on indoor tracks, the plastic mount provides a much smoother and more forgiving driving feel.

The aluminum version generates more traction, but also makes the car more aggressive and increases the risk of traction rolling.

ARB Mounts

For the anti-roll bar mounts, I recommend using a 1.5mm shim as a spacer to avoid compressing the plastic ball joint.

If tightened too much without spacing, the ball joint can bind and no longer move freely, which negatively affects the suspension performance.

Bulkheads and Motor Mount

There isn’t much to add here. I use threadlock to securely fasten the pulley shaft onto the motor mount to ensure it stays in place during racing.

Belts

I want to highlight our three belt options:

1. Kit version the standard across all classes, reliable and works in every situation.
2. White Low-Friction belts designed for slower classes to reduce rolling resistance, making the car noticeably easier to drive.
3. 3.5mm belts made specifically for modified classes, high-traction surfaces, or bumpy tracks. These are used less frequently but offer maximum durability when needed.

Upper Clamps

Next are the upper arms. I also use Team Titan screws here. For stock setups, I prefer slightly longer screws than the kit provides typically 10mm since we often run slightly higher shims, ensuring proper fit and consistent performance.

Steering

There isn’t much to mention here. As an option, we have the aluminum steering, but currently I only use it in modified setups.

I’ve tested both options multiple times, and I find the plastic steering provides a smoother and more forgiving feel. I also secure the steering posts with thread-lock to ensure they never come loose during racing.

Top Decks

We have the option of two-piece top decks, which work very well on the ARC A11.

I especially recommend them for tracks with many hairpins and weight shifts, as they provide added flex and stability under load.

Upper A-Arms

I recommend drilling the body stop positions with a 2.8mm drill to allow more adjustment options.

I also drill the hole on the rear this adds a bit more flex and makes the car feel smoother on track.

Shocks

Next are the shocks. As an option, I use the titanium nitride coated shock shafts for even smoother damping performance and improved consistency on track.

I sand the shock shaft shim with 2000 grit sandpaper down to a total thickness of 1.38mm. This makes the shocks noticeably smoother while still keeping them properly sealed and reliable.

Upper Shock Caps

It is very important to drill the hole with a 1.1mm drill bit. This allows you to run the shocks without rebound and ensures a more consistent damping behavior.

Front Bumper

Here I use the optional upper carbon bumper brace. Because it is mounted directly to the bulkhead, it has a noticeable impact on the chassis flex characteristics, which gives the car a more controlled and precise driving feel for me.

Important note! For the upstop limiter, the additional plastic parts are required:

• R151081
• R155008

Battery Holders

There isn’t much to mention here. The battery holder has been completely redesigned and is now adjustable in all directions, allowing for precise positioning.

As a tip, I recommend placing a 1mm shim underneath the entire battery holder. This raises the assembly slightly and provides additional setup flexibility.

Battery Holder Pro Tip

As you can see in the picture, I removed the lower plastic tab from the holder.

This tab is mainly a safety feature, but removing it prevents the holder from catching on the track surface, ensuring smoother operation and avoiding unwanted interference.