Skunk2 has dyno tested over and over until they found the intake manifold plenum spacer for the Nissan VQ35 engine found in the Nissan 350Z and Infiniti G35 to produce the absolute most horsepower of any other intake manifold plenum spacer. The Skunk2 Intake Manifold Plenum Spacer, 307-07-0400, increases the size of the intake plenum, lowers air intake temperatures, and supplies more air fo the front cylinders, which results in horsepower gains of up to 10 horsepower to the wheels, not to mention crisper throttle response. While some other intake plenum spacers are made from cheap plastic, the Skunk2 is made from carbon composite material that keeps heat transfer down, which in effect also increases power, and lowers intake temps. With this modification, the engine looks completely stock, and does not angle the plenum. Because the Skunk2 Intake Manifold Plenum is built to strict tolerances, it's very easy to install.