i recently bought the racing beat exhaust setup, from the manifold back and it came with an acv block off plate.

i know putting this in will stop feeding air to the cat (no big deal, i don't have it anymore and i plugged that pipe anyways), but will it keep my 5th and 6th ports from working?

thanks,
john

btw, this is on an s5 n/a.

 

Good question. I was going to remove my air pump, put on the ACV block off plate, but you are supposed to do the rear part as well.

THe actuator tube coming OFF from the racing beat setup, goes INTO the exit part (rear part) of the ACV thingie!! WTF!? It seems to me this would cause soem sort of problem, w/ the air pump pumping air into it, and the exhaust backpressure putting pressure on it, would it just cancel out in the middle?


I dont know, but I can't see an easy way to deal with this, i'm still trying to figure it out.

BTW< i have a s3 n/a w/ the stock 6 port 13b.

 

just gave racing beat a call...the acv is purely there for emissions, so no cat = no acv required. it won't affect the 5th/6th ports at all.

john

 

yeah on S5 cars the air pump will operate the ports unlike my car an S4 which uses the exhaust back pressure for that.

 

I'm glad you brought that up. I also have an S4, so in theory, if one person rev's the engine to 6 or 7k, then another person should be able to watch the ports open, correct? Whereas, the S5's need to be under load?

 

uh not really. When you are just reving it in neutral it will probably not open them up. I believe the car still has to be under load. I have tried this by just opening the butterflys and watching the actuators. I got nothing but I know that they open since I just cleaned my ports and make sure them could move freely in the slots. There is a slight chance they will open while in neutral but not likely. The easiest way to check is to dab some grease on the actuators go drive for a while and then check if the grease has been smeared around.

 

Just to clarify...The ACV CAN be removed on an S5 N/A. and the operation of the 6 ports and VDI will not be affected? Isnt there a hose going from the back of the Air Pump to the ACV? Or is my memory failing me? (Dont have car here now to go look)

Also, what is done with the two electrical plugs that go to the ACV? Are they just left unplugged? Wont the ECU be searching for them and wont that affect the ECU's performance?

 

yeah, there is a hose going into the acv, i don't know where it's coming from though.

i'll find out this weekend and post what happens when i pull mine off.

john

 

you definitely need the airpump to activate the actuators/VDI. I don't know about the ACV though.

 

so tell me if this all makes sense:

1 - we all know you need the air pump for your 5th&6th ports to work

2 - the only outlet of the air pump goes directly into the acv

3 - no acv means the air pump's outlet goes nowhere, meaning no 5th&6th ports :-(

maybe the dude at racing beat was confused with what model i had, but it would make sense that i'd need both the air pump and the acv for working 5th&6th ports.

john

 

I believe you can make a little gadget that allows you to rid the car of the old acv. I saw a thread on that here a while back. Do a search on it. Or you could do that electrical actuation thing and throw away the acv and pump. I think it cost a good bit of cash to do it though.

 

Ahhh...yes. Exactly my point. The only outlet goes into the ACV on our cars (S5). Can anyone shed some light on this S4 v. S5 confusion?

 

well S4 cars pump is the same but since our (S4) cars use back pressure it don't matter if you remove the ACV the pump just makes a whirring noise when you rev.

 

So what actually activates the S4 ports - split airt pipe? The diagrams in the FSM are terrible :?

 

I believe so. The split air pipe is pressurized by the backpressure of the exhaust, which pressurizes the actuators which in turn open the ports. Correct me if i am mistaken..

 

YOu are correct sir. There is a small rubber hose that hooks up to the little pipe on the actuators and that is hooked to the SAT(split air tube)

 

I was looking at my S5 manifold for where the air is tapped for the 6port actuators. It is at the very inlet of the ACV. If you remove the ACV on a s5 car the hose that feeds air from the air pump to the actuators will be removed as well. You could patch something together or just leave the ACV in there even if it does nothing. Port actuation will not be affected by removing the cat.

The s4 cars get the pressure for the actuators from the backpressure from the cat. It is pushed up the split air pipe then through a small dia tube to the 6port actuators. you can pull out the ACV but NOT the cat. If you have a cat it's a good idea to KEEP the ACV.

Of course there are mods that work around these problems.