Ultra Racing Rear Lower Side Brace Kit - Pair / 8 Point • RLS8-789P

Ultra Racing rear lower side chassis brace kit for Mazda MX-5 MK3 / MK3.5 / MK3.75 NC models listed in the compatibility table.

The Ultra Racing RLS8-789P is a pair of rear lower side / rear member side braces designed as an aftermarket chassis reinforcement upgrade for the third-generation Mazda MX-5 NC.

The kit consists of separate left- and right-hand braces mounted along the rear lower sides of the chassis. Together they provide an 8-point reinforcement arrangement, with four mounting points per side, helping reinforce the lower suspension and chassis mounting areas and reduce unwanted movement under cornering loads.

Product details:

• Brand: Ultra Racing
• Part number: RLS8-789P
• Product type: Rear Lower Side Bar / Rear Member Side Brace
• Position: Rear lower chassis - left and right sides
• Brace specification: 8 Point total
• Configuration: 2 x 4-point side braces
• Quantity required per vehicle: 1 pair
• Quantity supplied: 2 braces - left and right
• Material: Steel
• Finish: Ultra Racing white
• Designed for vehicle-specific chassis mounting points

Common reasons for fitting:

• Reinforce the rear lower chassis structure
• Reduce unwanted movement around rear suspension mounting areas
• Help the suspension maintain more consistent geometry under cornering loads
• Improve chassis response during enthusiastic road or track driving
• Complement front, middle and rear member bracing upgrades

Fitment advice:

Ultra Racing application data identifies RLS8-789P for the Mazda MX-5 MK3 / NC platform from 2006 to 2015. Ultra Racing Japan also lists the brace for the NCEC 2.0 application, while broader Ultra Racing and specialist catalogue data identifies the product across the NC generation. For imported, modified or previously repaired cars, matching the mounting arrangement on the vehicle before installation is recommended.

Other items to consider purchasing:

• Ultra Racing front strut brace
• Ultra Racing front lower / member brace
• Ultra Racing middle lower / member brace
• Ultra Racing rear lower / member brace
• Ultra Racing anti-roll bars
• Replacement chassis or suspension fasteners where existing hardware shows wear or corrosion

Useful tools / consumables:

• Socket and ratchet set
• Torque wrench
• Suitable vehicle lift or axle stands
• Penetrating fluid where existing underbody fasteners are corroded

Difficulty guide: Intermediate DIY / workshop installation. Safe access beneath both rear sides of the vehicle is required and both braces should be positioned correctly before final tightening.

Why Ultra Racing?

Ultra Racing specialises in aftermarket chassis and handling upgrades. Its lower chassis braces are designed to reinforce key mounting areas and reduce unwanted movement through the vehicle structure, helping the suspension operate more consistently under load.

What's in the box:

• 1 x left-hand Ultra Racing rear lower side brace
• 1 x right-hand Ultra Racing rear lower side brace
• Required additional mounting hardware where supplied by Ultra Racing

Installation notes:

The vehicle will need to be safely raised to provide access to the rear lower chassis mounting locations. Install the left- and right-hand braces in their respective positions and check clearance around suspension, exhaust and surrounding underbody components before final tightening. Ultra Racing advises that its braces generally use existing OEM mounting points and original fasteners unless additional hardware is supplied. Reassemble and tighten all mounting hardware to the appropriate vehicle or manufacturer specification.