I have a S4 JDM TII engine in my car and a S4 TII USDM BAC valve in my hand. (It is currently blocked off.)

I was thinking about grinding a small channel from that little hole on the BAC (The hole with idle adjustment screw on the other side) to the larger valve opening, so that I can adjust the BAC. This would be similar to the channel that is actually on the USDM UIM, for the BAC valve to be adjusted.

First I should ask... Do you understand what I mean? And... Will this work? Will I be able to adjust the idle now??

 

Sounds like it will work, as long as you aren't creating a static vacuum leak.

 

or you could buy a USDM UIM.. not like they are super rare or expensive. the hardest decision at that point would be which brake booster port you want to use.

 

Even though they might be pretty common and cheap... I don't really have the time or money to wait around for a USDM UIM. I was just making sure this would work. All I could find in a search were snippets of people complaining about not being able to adjust their idle. So, I figured this might be a free solution for me, considering I have a Dremel-type tool.

 

Give it a shot, but if you look at how the hole is cut on the USDM manifold it's got this tapered design to it (at least, on the s4. Not sure about s5).

 

do what you want, usually on Jspecs i remove the intercooler and adjust the idle manually that way.

 

I mess with the idle a bit that way... From what I've read, the BAC valve doesn't allow idle to drop lower than 750 RPMs. That is what mainly concerns me.

 

in an ideal world, with all brand new electrical components i'm sure it would.

 

lol... Very true. I suppose we'll see what happens.