BBR MX-5 ND to NC Gearbox Conversion Set

The gearbox of the Mazda MX-5 ND can unfortunately only be described as a weak link. Mazda themselves have released many revisions due to failures, and even the latest version of the gearbox is certainly not robust enough for longer track use or greatly increased torque.

Our answer is, just as Fiat decided with their turbocharged 124s with higher torque, to use the well-proven gearbox of the Mazda MX-5 NC.

This is a complete conversion kit that includes tapered and parallel locating studs, allowing a Mazda MX-5 NC 6-speed gearbox (not included) to directly replace the MX-5 ND unit. The Power Plant frame is directly bolted to the NC gearbox, and the original ND driveshaft is used without modification. This way, the gearbox in the ND can withstand up to 300 HP and 350 NM.

Included parts:

• Clear anodized billet aluminum adapter plate

• Lightweight billet steel adapter flywheel including pilot bearing

• Aluminum dust cover plate

• All required fasteners

• Installation diagram

Notes / additional requirements:

• A 6-speed clutch of the Mazda MX-5 NC is required.

• An NC slave cylinder of the MX-5 is required, and the hydraulic line of the MX-5 ND clutch must be adapted.

• We recommend a shorter final drive ratio.

• The gearbox tunnel of the MX-5 ND needs to be deformed (dented a few mm) to clear the MX-5 NC clutch fork lever.

• A small section of the NC gearbox needs to be removed to clear the starter motor of the MX-5 ND, and a dust cover is provided.