Intake System
An induction system with two modes is used to increase torque at low engine speed. Both the intake manifold and the equalizer tank are made of aluminum.
A moveable damper is located in the common area of the intake pipe. The damper separates the area lengthways into two chambers. The damper is controlled from completely closed to completely open, with no intermediate position. Up to an engine speed of 3200 rpm the damper is closed and the damper is open at higher engine speeds.
By dividing the area into two separate chambers, the area functions as two secondary intake pipes. The primary pipes are the cast pipes which lead to the inlet valves of the respective cylinder's intake valves from the collection volume. A closed damper provides secondary pipes while an open damper gives short secondary pipes.
Engine speeds up to 3200 rpm
The combined length and volume of the pipes is tuned to the piston movement and the valve opening times. The result is that the air pulses in time with the valve opening times. this means that the air is pumped into the cylinders when the inlet valves are open. The system gives a high a volumetric efficiency, that is, fills the cylinders and therefore produces a high torque.
In order not to disturb the pulse frequency the left chamber supplies 1, 4, 6 and 7 while the right chamber supplies cylinders 8, 3, 5 and 2, this is to interact with the firing order 1-8-4-3-6-5-7-2.
Engine speed (RPM) greater than 3200 rpm
At engine speeds greater than 3200 rpm the throttle opens. At these speeds the character of the pulses change character at the same time as a greater volume is required to supply the cylinders with air. The whole area/volume now supplies all cylinders. The common volume and the shape of the pipes is designed to exploit the pulses which occur in this engine speed (rpm) range.
If the damper does not open at 3200 rpm there is marked deterioration in performance from 3200 rpm up to 5000 rpm.