I was thinking about removing the air pump. Is it true that the removal will keep my 5th and 6th port from opening? How much horsepower loss or gain will i get from removing it?

 

You have an s4, so the aux ports run off of exhaust backpressure, not the air pump. You will gain maybe 1/2 hp and 5 or 10 pounds by removing it, but it will no longer be in the way in the engine bay.

 

^but that would be doing the mod incorrectly.

If you remove the airpump then you should be removing the cat as well or you'll end up killing the cat.

Cats == $$ when emissions time comes around or extra cash in your pocket if you sell it.

So Yes,
It would kill your 5/6th port IF you removed the cat as well(not enough backpressure) and put in a test pipe.
Racingbeat does sell a presilncer which has a pickup tube in there which is suppose to develop enough back pressure to activate the ports.

 

If I didn't open up my ports, what kind of symptoms could I expect?

 

lack of high end power

 

Yeah, I forgot about that part. He lives in Minnisota, so he prob doesn't have emmisions. If that is the case, you can get the rb downpipe and presilencer to replace the cats and be done with it.

 

if you want to sell the air pump, let me know. thanks

 

I am having a 100RPM pulsation above 1700RPM. Is this related to the flaps?

 

sorry to steal thread... but i just purchased an s5 and the air pump has been removed... along w/ cats... he said something about they welded a plate in for backpressure.. dunno. but car will not idle smooth it just revs from about 100-800 constantly at "idle"

 

Sounds like a bad TPS.

 

So if i strait pipe my exhaust will my 5th and 6th port open still. If not how much power is lost

 

has anyone proven that the RB presilencer will indeed activate the 5th/6th ports properly? (I have the RB catback allready, and soon plan on getting the matching RB header and presilencer to go along with it. ) Now I have them operating off the air pump, which works fine, but I would like to remove the pump and the ACV as well.

 

Yes. I have an apex N1 catback and it opens them without a problem.
To the OP, if you run just a straightpipe, your aux ports won't open. You need something to send the exhaust backpressure up to the actuators. The only aftermarket solution I know of that does this reliably is the racing beat presilencer.
If they aren't working, then you will lose a lot of top end. If you wire them open, you will lose lot of bottom end.