Nissan Fairlady Z S30/S31 (L-Engine) | HPI Reinforced 6-Speed Transmission

S30 Transmission
Part Number: HPKM-N02
 
Trusted by numerous competition vehicles, the HPI Reinforced 6-Speed Transmission is engineered to handle up to 50 kgf·m of torque and 430 PS.
 
Key Features & Design:
Ideal Gear Ratios: The 1st and 2nd gear ratios are designed closer to the 3rd gear, and the 6th gear is brought closer to the 5th gear for maximum enjoyment in circuit and drift driving.
Unlike raw competition dog boxes—which often produce loud whining noises due to rough tooth surface finishes and low meshing rates—this transmission is optimized for daily street use without awkwardness.
Enhanced Strength: Gear strength is boosted by increasing gear diameter through ratio adjustments, or by reducing tooth counts and making each tooth larger via module changes (without altering ratios).
Decreasing the helix angle reduces forward thrust shock input to the countershaft, effectively preventing counter reverse gear end-face breakage.
Superior Operability & Refinement: Building on the reliability of the stock "FS6R92A" platform, HPI optimizes strength and gear ratios to deliver operability and quietness incomparable to old-school synchro or dedicated dog transmissions.
Precision Assembly: Assembled by hand in a dedicated, temperature-controlled, dust-free room using HPI's original one-off SST (Special Service Tools) with meticulous component checks.
Assembled while working in high-performance COA lubricants to reduce metal fatigue and ensure smooth shift feel.

 
Product Specs & Specifications:
Exclusive S30 / S31 L-Engine Design
Max Torque: 50 kgf·m / Max Output: 430 PS

 
Important Notes & Warnings:
Competition Part: This product is designed for motorsports use prioritizing performance under extreme conditions and is not covered by warranty.
Gear damage may occur if input exceeds design limits.
Must be used in a set with a NISMO clutch.
Must use NISMO gear oil. Using unapproved additives may cause damage.
To prevent heavy shock loads on downshifts caused by road surface torque feedback, please match engine revs before downshifting.
Professional installation by a certified mechanic or tuning specialist is strongly recommended.