Basicly does it matter which way the flap swings. In my S4 it is the big AFM and the FSM shows the backwards D shape on the top and instide the flap swings side ways. It was pointed out to me that my AFM was rotated so the flap doesn't swing sideways...more like it swings up. In case your wondering I have a cone filter that replaced the stock air filter box. Is there a "best position for this unit?

-Max

 

Here is an example picture (not my car, just as an example)

-Max

 

I know that the angle of it had to be less then a certain degree. If its not the car won't idle right.....

 

You do not want the flap swinging on a vertical plane, try to keep it as close to horizontal as possible. If you search the forums you should be able to find a post about swapping out the S4 AFM for the S5 AFM which is a plunger style.

 

From the reading that I did on the forum, as well as my person experience - The S4 AFM works as long as the flapper is horizontal (or thereabouts). If the black "D" is facing up (stock position) or the waffle pattern is facing up (like in the pic) you are OK. If the AFM is tilted too much - or is on it's side - you will have issues. If it is tilted or on it's side, gravity will hamper the flapper's proper operation.


I have been running the AFM upside down for over a year (the car in the pic is mine ) with no ill effects noticed. That being said, some people have had issues with idle when the AFM is upside down. Personally, mine has been trouble-free in this configuration.

 

Thanks for your help Nick86, I love your cold air box.

Can our S4's use the S5 AFM?

-Max

 

Yes but with some wiring difference. There was a thread about it...

 

I don't know, any good design for a flapper door should be counterbalanced. It shouldn't matter what orientation it has.

In my racecar I rotated it so that the flapper door hangs straight down. I didn't do it for any real reason it just happens to fit nicer that way.

I have had no idle problems, no MPG problems, no power problems.

ed

 

It's suppose to matter, slightly. The "Black box" should either be facing the sky or the ground...

Wait : You guys still have an AFM?

Later,
-Markus

 

The S5 AFM swap is a waste of time, no gain there. Just make sure the flap moves in the horizontal plane and you'll be fine.

 

Yep! Until they come up with an emissions friendly standalone.

 

There will never be such a thing. Standalone's are illegal because you can adjust them. If you can adjust them, you can increase the amount of emisisions produced anytime you want. Even if you tune it perfectly and prove it has low enough emissions output, you can just drive home and change it. The lawmakers don't want you to be able to do that.