Tomioka Racing Roll Center Adjuster – Subaru BRZ / Scion FR-S / Toyota 86 (ZN6/ZC6)

Overview

Lowering your Subaru BRZ, Scion FR-S or Toyota 86 is great for looks and center of gravity – but it also pushes the front roll center way below the car’s center of gravity, which can actually increase body roll and hurt front grip.  

The Tomioka Racing Roll Center Adjuster (TR-CS2005) is an extended front lower ball joint kit designed specifically for the ZN6/ZC6 chassis. It raises the front roll center by approximately 30–40 mm on a 30–40 mm (1.2–1.6") drop, helping bring your suspension geometry back into an effective range for street, track day, time attack, and autocross use.

Why you want roll center correction

On a lowered BRZ / FR-S / 86 without correction:

- The front roll center drops well below the center of gravity  
- Body roll increases even though you’ve added stiffer springs  
- The outside front tire gets overloaded and loses contact patch  
- Steering response can feel lazy and vague mid-corner  

By raising the roll center with extended ball joints, this kit:

- Reduces front body roll without relying only on big sway bars  
- Improves front-end bite and mid-corner grip  
- Helps keep camber and toe behavior more consistent through travel  
- Gives you sharper turn-in and more predictable steering at the limit  

Key features & benefits

- Vehicle-specific extended ball joints
  Designed for the Subaru BRZ, Scion FR-S and Toyota 86 ZN6/ZC6 chassis to correct roll center on lowered cars.

- 30–40 mm roll center correction  
  Ideal for cars lowered roughly 1.2–1.6 inches (30–40 mm) with lowering springs or coilovers.

- High-strength alloy steel construction  
  Housings and pins are made from high strength alloy steel for durability under aggressive street and track use.

- Lightweight design  
  Engineered to be strong without unnecessary weight added to your unsprung mass.

- Direct bolt-on installation  
  Installs in the factory front lower control arms using OEM-style hardware and tapered pins – no cutting or welding.

- Improved stability when lowered  
  Helps your BRZ / FR-S / 86 feel more planted on turn-in, mid-corner and during quick transitions (slaloms, chicanes).

- Perfect for dual-use cars  
  Works well for daily driven cars that see weekend canyon runs, HPDEs, track days or autocross.

Vehicle fitment

- 2013–2020 Subaru BRZ (ZC6)  
- 2013–2016 Scion FR-S (ZN6)  
- 2017–2020 Toyota 86 / GT86 (ZN6)  

> Note: Designed for the first-generation ZN6 / ZC6 FR-S / BRZ / 86 platform. Not for second-generation GR86/BRZ.

Technical specs

- Construction: High-strength alloy steel  
- Type: Extended front lower ball joint / roll center adjuster  
- Roll center correction range: ~30–40 mm (with typical 30–40 mm drop)  
- Installation: Bolt-on, reuses factory control arms  
- Quantity: Sold as a pair (left & right)

What’s included

- 2 x Tomioka Racing roll center adjuster ball joints
- 2 x pins / hardware needed for installation  

Installation notes

- Professional installation and a full alignment after installation are strongly recommended.  
- Best results are achieved on cars lowered approximately 30–40 mm (1.2–1.6") with quality springs or coilovers.  
- For cars lowered 30 mm or more, pairing these with bump-steer correcting tie-rod ends is recommended to further refine steering feel and toe curve.

Big brake kit (BBK) compatibility notice

Because this kit uses an extended ball joint pin, the ball joint housing and control arm sit closer to the rotor hat than stock. On some big brake kits with tight rotor-to-knuckle clearance – especially AP Racing / Essex Sprint and Competition kits – this can cause physical interference between the ball joint / LCA and the rotor hat.

- If you are running an AP Racing / Essex Sprint or similar BBK with very tight clearances, this kit may not be directly compatible without additional changes (e.g., different LCAs or alternate hats approved by the BBK manufacturer).  
- If you are unsure about fitment with your brake setup, contact us before purchasing so we can help verify compatibility.

For cars on stock brakes or most OEM-style rotor setups, this roll center adjuster is typically a straightforward bolt-on upgrade.

Recommended supporting mods

For a well-balanced FR-S / BRZ / 86 handling package, pair the TR Roll Center Adjuster with:

- Quality coilovers or performance lowering springs
- Adjustable front camber bolts or camber plates  
- Bump-steer tie rods (for cars lowered 30 mm+)  
- Performance alignment tailored to your use (street / canyon / track)  

Dialed in together, these parts give you a front end that turns in harder, grips better, and stays more predictable when you push the car.

Specifications

Kit Contents:

• 2 x Roll Centers
• 2 x Pins