In testing the 991.2 GT3 and RS we found the air intake to be restrictive.  With the addition of the larger 93mm Throttle Body and Center Plenum you can allow the car to breathe better.  We measure this by comparing the atmospheric pressure outside of the Plenum to the pressure inside the plenum. Ideally, we want no differences.  This change helps reduce pressure losses from about 0.6psi down to 0.1psi when used with our Dual Reverse Cone Airbox.  

Kit Includes:

Big Mouth Center Plenum

93mm Throttle Body

Touring Airbox Adapter

Adapter Harness