Black Sunshine 07

what are charge motion delete plates and what do they do?

Burnsy

they replace the original plates with ones that do not have the butterfly valve which limits air flow, so they increase air flow and allow the engine to breathe better

AmericanMuscle4.6GT

the original plates are designed as a manifold vacuum attenuation system. under low rpm's, they create a narrower intake runner; increasing air velocity and thus maintaining sufficient manifold vacuum. they open at 3000 RPM to "clear the way" for the increased airflow demands of the higher rpms. the effect is, they help generate low end torque and then "get out of the way" at higher rpm's. the problem is, they don't "get out of the way" well enough, and thus can restrict airflow. therefore, removing them and substituting plates with larger openings is good for some hp gains up top but torque loss down low. hope this helps.

judojohn

HAS ANYONE BOUGHT STOCK PLATES AND REMOVED THE RESTRICTIONS
THERE ARE SOME ON EBAY CHEAP

JGT

I've been looking at these. It seems that the loss of low end torque is minimal, and well worth the 5-10 hp gain across the rest of therpm range.

However, I've been reading and it seems some people have a problem,in the cold weather, with the engine revving up high on it's own? Can anyone give any more details on this? It is not the normal few minutes of higher revving we all get when cold starting the car, it seems to be more severe with the delete plates.

howarmat

The only higher revving i experience is that of the cold weather, nothing that is not out of the ordinary

GT Bob

The point of the plates is less about vacuum and more about increasing the port velocity of the intake charge as it passes the intake valves into the cylinder. Higher port speeds mean more torque. the small opening in the CMCV plates helps this, and by opening up at 3K rpms, they allow alot more airflow on the top end. At higher rev's port velocity means nothing, and simply just moving volume is what matters.