Trust GReddy Turbo Kit T518Z 10.0cm - S14 S15

The standard STI alloy diff mount is a good looking unit, but it has rather soft bushings which are designed to minimize NVH, rather than hold the diff steady.

The Cusco diff mount being made out of sheet steel formed in to a box structure, combined with stiff bushings, holds the diff tight. For the ultimate lockdown combine this mount with the Rear Differential Mount Collars Part No. 692 928 A, which are installed in the rear subframe.

The standard pitch mount and even the enhanced STI pitch mount, still allow some movement, as they are compromised by their bushings which are designed to prevent excessive NVH. This Cusco item is heavily biased towards stopping movement, rather than preventing NVH, so as expected more noise and vibration can be detected (mainly on startup).

As standard the GRB Impreza only has a single adjustment for toe, so you basically have no control over the rear geometry. Adjustable lower and toe arms are common, but there are very few adjustable upper rear arms.

This upper arm is the usual Cusco quality, and of course fits perfectly. There are only two things that would make it better. Firstly there are no fixings for the ABS cables, so you have to use zip ties, and secondly the inner bushings are hardened rubber rather than the superior pillow ball.

Easy to install, fits well and didn’t rattle

great price, amazing service from RHDJapan keeping me updated on my order status through the holiday, impressed with the packaging as well as the part, i can't wait to install the pan on my project build.