This new intake plenum replaces the upper half of your factory intake manifold. This plenum bolts directly up to your car with zero modifications, and also allows the use of the factory strut bar, and engine cover. This unit will fit the 350z, the G35, and the FX. *** engine cover may not fit with the G35 or the FX35 ** This plenum increases the volume to the middle and more importantly the front cylinders. The factory plenum utilizes a very aggressive angle as it caps off the front cylinders. This new plenum equalizes the flow to all cylinders, while also increasing the total plenum volume. This plenum also uses a very versatile plastic to achieve a smooth interior for superior flow properties. The plastic also allows a lighter overall weight, by about 4 lbs. The overall temperatures of the plenum have also decreased by about 30 degrees farenheit. This helps with heat soak problems and to help lower air intake temperatures. Our plenum has shown a solid peak gain of 8 rwhp and a consistent gain throughout the RPM range. When matched up with our high flow cats, they together have shown a dyno proven peak gain of 17 rwhp.