S3 8P Exhaust valve

Bryant1998

Bryant1998

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Been looking through some old threads but can’t seem to find a definite answer, wanting to know if it’s possible to open the exhaust flap in my S3 8P (59) so it’s a bit louder?

It feels like the flap opens around 4k and sounds so much better so wanting that 24/7 if anyone can help? Cheers
 
Bryant1998 said:
Been looking through some old threads but can’t seem to find a definite answer, wanting to know if it’s possible to open the exhaust flap in my S3 8P (59) so it’s a bit louder?

It feels like the flap opens around 4k and sounds so much better so wanting that 24/7 if anyone can help? Cheers
Click to expand...
In short Noooope , 8p exhaust are boost pressure actuated no where its located im not sure wgere its located so you could get a cheapish aftermarket back box

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e9_mustii said:
In short Noooope , 8p exhaust are boost pressure actuated no where its located im not sure wgere its located so you could get a cheapish aftermarket back box

Sent from my SM-N976B using Tapatalk
Click to expand...
Or use this flaw and turn it into as a opurtunatly and get a new zorst

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e9_mustii said:
Or use this flaw and turn it into as a opurtunatly and get a new zorst

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Click to expand...

Haha was thinking of cheap mods, just paid insurance and need new tyres, was only at r tech a few weeks ago aswell non stop money
 
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In actual fact the flap is not boost actuated but vacuum actuated at about 3.5k revs. The electrically acting vacuum pump is located near the rear bumper and the actuator is located above the exhaust pipe.
It is possible to disconnect the actuating arm and wire it open.
You just have to make sure you wire it in the open position and not the closed position by gauging the position of the actuating arm whilst looking down the exhaust.
It is BCS exhausts that have the boost activated valve.
 
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prt57 said:
In actual fact the flap is not boost actuated but vacuum actuated at about 3.5k revs. The electrically acting vacuum pump is located near the rear bumper and the actuator is located above the exhaust pipe.
It is possible to disconnect the actuating arm and wire it open.
You just have to make sure you wire it in the open position and not the closed position by gauging the position of the actuating arm whilst looking down the exhaust.
It is BCS exhausts that have the boost activated valve.
Click to expand...
Yep that it was what i ment but my terminolgy
My bad i might actually do that too

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prt57 said:
In actual fact the flap is not boost actuated but vacuum actuated at about 3.5k revs. The electrically acting vacuum pump is located near the rear bumper and the actuator is located above the exhaust pipe.
It is possible to disconnect the actuating arm and wire it open.
You just have to make sure you wire it in the open position and not the closed position by gauging the position of the actuating arm whilst looking down the exhaust.
It is BCS exhausts that have the boost activated valve.
Click to expand...

Any instructions for that? Got plenty of spare time...
 
From memory, you can move the linkage up and you get to a point where the actuating rod can be pulled out. Twist that round so it won’t interfere with the linkage any more.
Look down the exhaust pipe to find the point when the valve is horizontal then do your best to wire it in that position.
I didn’t notice much difference in sound output when I had a go
 
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e9_mustii said:
In short Noooope , 8p exhaust are boost pressure actuated no where its located im not sure wgere its located so you could get a cheapish aftermarket back box

Sent from my SM-N976B using Tapatalk
Click to expand...
Vacuum or boost?
 
Jon_ m_ s3 said:
Vacuum or boost?
Click to expand...
Boost mate theres a little hose connected to your backbox of the stock exhaust and will only have enough pressure to open the valve when your heavy footed (certain amount of boost pressure)

Vaccum is more stationary which Will keep it closed

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e9_mustii said:
Boost mate theres a little hose connected to your backbox of the stock exhaust and will only have enough pressure to open the valve when your heavy footed (certain amount of boost pressure)

Vaccum is more stationary which Will keep it closed

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Click to expand...
Iv seen the hose but it connects to a small pump ? What I would like to know is the valve open or closed when engine is not off? Mine is seized and won't to replace it, but I need to know if it's open or closed to buy the correct one.
 
Jon_ m_ s3 said:
Iv seen the hose but it connects to a small pump ? What I would like to know is the valve open or closed when engine is not off? Mine is seized and won't to replace it, but I need to know if it's open or closed to buy the correct one.
Click to expand...
You tried taking it off putting a load of wd40 and blowing air through it ? Dont use to much pressure and especially not in the wrong end lol it'll probs go bang.

In theory it will be closed untill enough boost (positive pressure is generated) to move the actuator and open the valve to allow the exhaust to flow better and louder, if im not wrong the twin pipe on the s3 is the one close to back box goes in and filter through there where as the one on the outerside is valved in the normally closed position.

Again im not 100% sure as i got a straight through decat system without the valve

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e9_mustii said:
You tried taking it off putting a load of wd40 and blowing air through it ? Dont use to much pressure and especially not in the wrong end lol it'll probs go bang.

In theory it will be closed untill enough boost (positive pressure is generated) to move the actuator and open the valve to allow the exhaust to flow better and louder, if im not wrong the twin pipe on the s3 is the one close to back box goes in and filter through there where as the one on the outerside is valved in the normally closed position.

Again im not 100% sure as i got a straight through decat system without the valve

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Click to expand...
I have cat back but it's tooo loud lol, wanting to put just the back box on with working valve, the original one is beyond repair it is just crumbling, I have see on here somewhere that is open then when the pressure builds up it closes then when you get above 3 to 4000 RPM it opens again ‍♂️ lol
 
Jon_ m_ s3 said:
I have cat back but it's tooo loud lol, wanting to put just the back box on with working valve, the original one is beyond repair it is just crumbling, I have see on here somewhere that is open then when the pressure builds up it closes then when you get above 3 to 4000 RPM it opens again ‍ lol
Click to expand...
I dont think its loud at all mines quite until you hit give ut the bean or at 70-80 then it sound like an animal lol u sure u dont have a exhaust leak, and that wouldn't make sense i mean on cold start yea it would open abit and then close but if its stuck open it would always be loud

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