This is an adapter kit for anyone using the S-chassis or similar Nissan/Infiniti multi-link rear, who wants to be able to use the aluminum rear uprights (from an early 90’s Q45 or 300zx) to save unsprung weight. The challenge with the substitution is the coilover mounting arm on the upright is entirely different, and at the wrong angle, which means even using the Z32 lower forks on the coilover won’t fix the binding.
This adapter then allows using these uprights on an S14/S15 or subframe swapped Z31, with a more common S-chassis style coilover, either S13 coilovers directly, or the repurposed ones that ship with the Stance and Powertrix Z31 kits (just don’t use the inserts provided). The kit includes spacer rings for coilovers with narrow sleeves in the lower bushings.
Estimated unsprung weight savings will be around 6-7lbs per side. Note that the height offset of the new coilover mount is about 40-45mm vertically, that distance is lost from the minimum adjustable height on the coilover, this will vary based on alignment and coilovers used.