ok I know all about the 5th and 6th ports and such. BUT I keep seeing people talk about VDI an a certain RPM and "lockign it in hight" after removing the ports and so on.

Well my question is pretty simple here it goes:
WTF is VDI?? LOL

I did a search and came to an interesting thread on the diff between a S4 and S5 N/A engines and VDI was in there. is the VDI only for S5 engines? If so then that would explaing me not knowing a damn thign about it since I ahve a S4.

DO TELL.

 

Yes it's only in S5. It blocks off some of the intake runners at low RPM for more torque. It's on the Upper Intake manifold, below the Dynamic Chamber.

 

The VDI stands for Variable Dynamic Intake (Effect).

It is only on S5 N/A's.

It simply moves a valve at 5500 RPMs that changes the path of airflow. It allows air air to enter the engine at a higher velocity, and therefore, acts as a natural SUPERCHARGER (yes it does ram a small amount of air in there).

You can really feel a kick at 5.5k whe it's working right... just like the 6-ports

 

It's Vtec for your Rotary! I can't wait to get my VDI badge for my FC!

Steve

 

OK thx. I knew I had read a out it in the Hayes Manual somewhere cus I knew what it stood for, but I forgot what it was.


OK one more question, why do soem of the S5 people talk about removing their ports and such when its activated by the airpump.

I regret removing my actuators and airpump on my S4 cus I foudn a site that explains how to make it work like an S5 system. The only reason I did it was because I put on a free flowing Exhaust so I didnt think I would have enought pressure to open them, oh well.

Also what activates the actuator for the VDI??