Even in the stock configuration you'll find the turbo inlets and intake runners with a nice film of oil on them. While this ensures your aluminum compressor wheels don't rust, it does nothing beneficial for performance! Oil in the intake tract will lead to oil deposits on valves, an oil film on the inside of the intercooler that affects cooling efficiency, and if bad enough, can potentially cause detonation. This problem gets compounded when horsepower is increased, engines are rebuilt with looser clearances (from forged pistons), ethanol fuels are used which result in lower piston temps and more blowby, etc. As you increase the amount of air coming out of the engine from blowby, you also increase the amount of oil carried out with it. In the GTR, this usually results in an oil spraying blow off valve and a messy engine bay, along with the mentioned negative affects.
The GT1R CNC Air/Oil Separator (AOS) is a maintenance free solution that's been proven in the most extreme conditions, ethanol fueled engines making over 1500hp.
T1 designed the AOS with detailed internal passages and a two stage separation system. The first separates the larger oil droplets from the air and the second stage separates the remaining smaller droplets from the air. The result is dry intakes and a fully recirculated maintenance free system with no oil smell. The oil that is extracted is returned back to the engine so you never have to worry about emptying a can or an overflowing can emptying itself into your turbo inlets.
They feed the AOS from both of the valve covers as well as the PCV fitting on the back side of the block, and the outlets of the AOS go to the turbo inlets.
The kit consists of a 3 piece CNC AOS, anodized black and engraved with the GT1R logo. The AOS is sealed with Viton o-rings and all ports are AN o-ring boss ports. T1 includes a 6AN check valve in the bottom of the AOS to allow oil to drain back and stop crankcase pressure from feeding the AOS from the bottom, where it's designed to drain. The AOS is mounted to the engine using supplied stainless steel hardware and a CNC aluminum mounting bracket. A complete installation kit is included with pre-assembled lines using Redhorse Products black AN hose and black anodized hose ends. Following the supplied instructions, installation can be done in less than 2 hours by a first time installer with a few basic tools, including the oil drainback system.