- Ported inlet Manifold
- Ported Trumpet Base
- Ported Plenum
- Aftermarket

This is the standard cast manifold (there are a number of variants but they all function similarly) which has been 'ported' out to 45mm at the trumpet base (top) and matched to stage III cylinder heads at the bottom (head side). The increased volume and smooth bore both contribute to better, faster air flow and therefore increase both performance and throttle response.

This trumpet base has been ported through to accept the 45mm radiused aluminium trumpets as shown. The shortened trumpets allow for greater clearance inside the plenum and improved volumetric flow.

The 72mm throttle body on the front of the modified plenum increases the surface area of the air intake by 30%. This allows for more air to be drawn through the throttle body and thereby increases the potential power output at high rpm. The fact that the surface area is increased also promotes faster throttle response.
The Carbon Plenum
A single carbon plenum is normally fitted with a larger throttle body than a standard plenum and therefore offers similar gains to the 72mm aluminium version. The wall thickness is obviously greatly reduced and the plenum therefore has a greater internal volume which promotes power output. There is of course also the aesthetically pleasing look of the black carbon.
Twin and triple throttle versions of the carbon plenum are also available. Although these do not always add a great deal to the overall available air volume they do effect the throttle response and 'driveability' of the car.
Throttle Bodies
Down draught throttle bodies are probably the ultimate in terms of air delivery and performance. Whether it be carburetors or injection bodies the fact that each cylinder has a direct 'portal' to the incoming air means that each cylinder is tunable (to a greater or lesser extent).The individual induction tract also means that the characteristics of the engine can be substantially altered by changing the length of the inlet manifold, size of chokes and length of trumpets. Optimising all of these factors can produce some really impressive results on a properly managed system.