Lets get back to talking about gen 3 engines not Gen 4 that have many changes.
First, in direct injection, the engine runs on direct injectors supplying the fuel >inside< the cylinder under normal driving speed.
There is no fuel being port injected at that time only air in through the open intake valves.
The IMRC flap has a corner of its area open for air flow aimed at one of the intake valves to increase air Swirl and mixing /movement within the cylinder before the compression stroke begins. The Gen 2 engines do not have the port injectors to provide any extra fuel.
When a significant amount of power is called for by the driver, the flap begins to open the airflow >area< , and depending on the program will begin to use the Gen 3 port injectors to add fuel through the intake valves >augmenting< the direct injection fuel to support the total power demand.
This is shown on published fuel map grid layouts that are changed by Tuners who must get more fuel to support higher power production for such items as super charging.


This is the overall design operation in these engines and does produce a large amount of torque over a wider power band extension on the upper RPM end, for the DOHC 5L design air flow capability.
Most of you do not know this operation well enough to make decision on how it all works together and when. Sorry is anyone takes exception.
Best not to try to compare with other designs and makes but understand what you already have.
Yes, the design attempts to combine best fuel efficiency but also power increase flexibility over a wide RPM band and to improve Emissions.
Emissions is the important item at low RPM where the engine spend 95% of its time and is taken care of with the VCT operation and the IMRC design together, regardless of what one may think.
Changing the operation, defeating any of the design parameters, will result is degradation of the original performance built into these engines.
Good luck.

 

Quote:

Originally Posted by Bluegrass

Lets get back to talking about gen 3 engines not Gen 4 that have many changes.

Ahhh the irony is beautiful... It also doesn't take a "significant" power demand to open the flaps. They also only have 2 positions, closed or open and are not variable. There would be an argument for them there if they were but they aren't.

Let's get back to talking about Gen 2 considering that's what the topic was about in the first place

 

Noting like running away, is there?
Good luck.

 

“gen 2 doesn’t have port injectors” lol the most accurate statement you made was that the system ATTEMPTS to utilize IMRCs as part of the broad powerband. That’s doesn’t mean it does it well or effectively

who’s running?

 

Well yeah the amount it contributes may be a topic for another debate, but I feel every little bit contributes to the overall performance envelope an engine has. That being said if mine ever go out, I don’t think I’ll be trying to fix them and just delete all together (especially since manifolds are becoming increasingly difficult to find).

 

Thats fine.
I gave a specified Gen3 reply and overviews with reference to Gen 2 difference.
But some can't resist trying to zero in on some fine point just to be relevant. It's called pissing in the wind.
As far as intake faps, all these engines need to be crank started and require some airflow past the flaps when closed. I did not specify any accuracy when they are opend but under program control but well a **** point is made of it.
Good luck.