i'm putting an S5 intake manifold on an S4 block, and i've noticed that the port air on the lower manifolds are different between S4 and S5. looks like you have to block it off. i'm just wondering though, if this is blocked off, what won't function correctly? i'm assuming the ACV uses that port to dump air into the intake?


thanks

 

The ACV puts air into the EXAUST PORTS. That is why it is called PORT air.

 

I'm assuming you're doing this to get the benefits of VDI. I would suggest using the s4 LIM mated to the VDI manifold: there's much less headache involved, and since you're not blocking any ports it will probably be better for performance. I did it this way and have been more than pleased with the results.

 

ok, thanks. i've looked at the FSM and have seen that.

yes, i am doing it mainly for the fact that the S5 manifold will work better with my stockport 13b, but also that my car is an S5, but i just have the S4 block, so the conversion won't be that complicated...
and i also must use the entire S5 manifold, so using the S4 is not an option

 

i've attached this pic to show what i am talking about. notice the lower port below the 2 main intake ports in the middle, and how it is has been blocked off.
i'm just wondering what this will effect? i.e what won't work or what will work differently, etc.

 

It's only going to effect emissions. No path to the front and rear side housings to pass the *port air* to the exaust ports in the rotor housings.

A series four manifold sends the acv air to the end of the manifold where it exits the somewhat square openings on each end of the manifold, into the front and rear side housings, where it goes straight down to the bottom of the front and rear side housings and exits into a passage that leads to the rotor housings and then into a hole hidden by the exaust diffussers.

That path exists no more with the series five manifold.

 

ok thanks for the info. i figured it was nothing more than emissions related. good to confirm that.

- Aaron