get an MX-3, MX-6, Ford Probe 2.5, get a V6 engine from MAZDA,... those have VRIS- Variable Resonance Intake System
kopirano iz interneta:
"VRIS
The first time you might have heard about the VRIS was by a showroom salesman if you bought your MX-3 new. But what the hell is it besides a marketing acronym? VRIS stands for Variable Resonance Induction System. Many car manufacturers uses this technology under different names but Mazda might be the one who pushed the technology the most (for the moment). The principle is quite easy to understand: to give the engine a long intake runner lenght at low rpm for optimal low-end torque and a shorter intake manifold lenght at high rpm to increase ram effect. If you prefer it's a VTEC for the intake... Basic systems usually supply each cylinder with a set of long and short intake runners and a valve dispatches the air between the two. Mazda engineers fine-tuned the V6's intake manifold to take advantages of resonance phenomenons. Using a pair of valves on the manifold and playing with a combination of opening and closing point they were able to extract more torque in the mid-rpm range. The figure belows shows the torque for the different valve combinations:
As you can see when both valves are open (shortest intake path), lots of torque is available from 4000 to 6300 rpm. When both valves are closed (longest path), a nice torque peak is found between 2700 to 3900. Finally combining #1 valve open and #2 valve closed gives another peak between 3900-4700 rpm.
This is very nice but what happen when you remove the closed box, overbore the throttle body, use a longer/shorter intake tube??? We all guess that the resonance points are affected and that the valve's switch points should be adjusted to provide the best torque possible. This is what my latest project is all about..."