Competition Spec Miata 5-speed gearset (SM legal)

Mazda Motorsports is committed to providing support for Spec Miata racers. Recognizing the challenges that come with aging vehicles and the increasing difficulty of sourcing parts, Mazda Motorsports has commissioned a motorsports version of the 5-speed gear set for 1990-2005 Miatas. This initiative ensures that owners of Spec Miatas can continue to keep their beloved vehicles on track and running for years to come.

The motorsports transmission gear sets offer several notable advantages:

  1. Enhanced Strength: The gear sets are constructed using a high-strength 9310 alloy, resulting in improved durability and resistance to wear and tear. This alloy upgrade ensures that the transmission can withstand the rigorous demands of racing and deliver reliable performance under extreme conditions.
  2. Improved Gear Design: Mazda Motorsports has implemented an enhanced gear tooth root design. This design optimization contributes to improved load distribution, minimizing stress concentrations and increasing the overall strength of the gears. As a result, the transmission can handle higher torque levels and shock loads, offering greater reliability and longevity.
  3. Consistency and Tolerances: The manufacturing process for the motorsports gear sets emphasizes enhanced consistency and tighter tolerances. This attention to detail ensures that each gear set meets strict quality standards, providing a precise, reliable pairing and meshing of the internal components transmission system. Racers can have confidence in the consistency of gear, wear, engagement, and accurate shifting, enhancing their overall driving experience.
  4. Improved Oiling: The motorsports transmission incorporates improved oiling paths and routing. This enhancement promotes better lubrication and cooling of the gears, reducing wear friction and heat buildup.  Additionally, a splined collar with oil grooves, which provides lubrication between the countershaft and splined gears, has been utilized.  The optimized oiling system contributes to extended component life, ensuring that the transmission performs at its best throughout demanding racing conditions.
  5. Enhanced Gear Treatment: As part of the manufacturing process, the gears in the motorsports transmission are shot-peened and cryogenically treated. Shot peening helps to increase surface hardness, improving resistance to fatigue and enhancing overall gear strength. Cryogenic treatment involves subjecting the gears to extremely low temperatures, which further enhances their durability and wear resistance.
  • Updated Shift Assembly: The 5th / Reverse hub experiences torque steps severe enough to cause excess friction during movement. Mazda Motorsports has addressed this issue by introducing a replacement hub and slider that has demonstrated exceptional resistance to torque stepping and ensures smoother engagement of 5th, as well as reverse gears and reduces the likelihood of premature wear during normal racing conditions.  Another improvement lies in the 5th gear thrust ring, which is now made from the same 9300 series of the gear set. This change significantly reduces wear on the thrust ring, enhancing its longevity and improving overall transmission performance especially by keeping 5th gear in place. The adoption of a single-piece 2nd gear synchro (available separately) offers improved performance under race conditions and reduces the cost of refreshes compared to the previous three-piece version. This upgrade streamlines maintenance and ensures consistent shifting performance on the track. Three-piece synchros are tailored more for smoother street shifting, but the inner cones do not handle race condition shifting anywhere near the single-piece design.

By offering this upgraded gear set, Mazda Motorsports reaffirms its commitment to supporting racers and ensuring the longevity of Spec Miata. With improved strength, enhanced gear design, consistent manufacturing, optimized oiling, and advanced gear treatment, these transmission upgrades provide peace of mind to owners and enable them to continue enjoying the thrill of racing with confidence.

Mazda Motorsports PT#- 0000-02-5800

The kit includes:

  • 5/R hub and slider
  • 2nd gear
  • 3rd gear
  • 5th gear pair
  • Input shaft
  • Counter shaft
  • Splined countershaft reinforcement collar
  • 5th gear thrust washer