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Discussion Starter · #1 ·
This is for the TTS massive crew.

On cold mornings or cold days, do you get smoke (or steam rather) coming out from both exhausts?
I've had a TTS backbox fitted and noticed this morning that its only coming out the drivers side. After a 10min drive to work i went and felt the passenger side exhaust tips and they were no where near as hot as the driverside tips.

Whats it like on your quad tipp'ed exhausts?
 

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I've not had a TTS but all TTs with more than one exhaust output have active exhaust systems that use only one output at low RPM to reduce exhaust noise. On the TTRS and my TT 3.2 the secondary exhaust came into use at ~3000 RPM.

Do you spend much time driving over 3000 RPM when you notice this?
 

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Discussion Starter · #3 ·
CastorAcer said:
I've not had a TTS but all TTs with more than one exhaust output have active exhaust systems that use only one output at low RPM to reduce exhaust noise. On the TTRS and my TT 3.2 the secondary exhaust came into use at ~3000 RPM.

Do you spend much time driving over 3000 RPM when you notice this?
I only noticed it when I started my car this morning. I had it started in the driveway and noticed that whilst it was idling steam was only coming out of the drivers side.

Mostly I drive under 3000rpm
 

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From what I've noticed. First thing more fumes come from passenger side, however, the driver's side tips get carboned up the most :?
 

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Ok... to the best of my understanding... (and from my experience)

When you first start the engine a valve opens on the left-hand tail pipes. This increases the volume of the exhaust as most of the gases bypass the main silencer (hence steam only coming from the left). If you start the car next to a wall (or something else that will reflect sound from the rear of the car), you will hear a metal 'tap' noise within a split second of you turning the key. This is the valve opening.

Once you have got moving and your revs have exceeded 2.5k (approx), or your speed exceeds 30mph (approx), the valve closes again to make the exhaust quieter and more acceptable on urban roads (German rules apparently...). Exhaust gases will then exit both sides of the exhaust, but predominantly the right-hand side (hence most carbon build-up).

If you pin the throttle on an open road and push the revs past 4 or 5k then the valve opens up again to give the exhaust a 'sporty' note. This will stay open until your speed and/or revs decrease again.

Other forum topics have described people removing the vacuum hose on the exhaust valve as this will keep the valve in its open ('noisy') position at all times...
 

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Following the post above...

The TTS have a vacuum hose from the engine to the exhaust. This controls the valve. If you do not have the vacuum hose that attaches to the valve then the process described above will not work in the same way. I assume that the valve would just stay closed and (as you describe) the gases will come out of the right-hand side only, and only that side will get hot.

As mentioned - you can overcome this by modifying the valve on the left-hand tail pipes so that it is in the open position at all times. This can cause a bit of a drone or a 'boomy' noise on the motorway, but very much up to the preference of the TT owner! :)
 

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I just checked mine quickly. It's had it's normal 15 mile commute about half an hour ago so it's still warm, but on tick over the passenger side exhaust is noticeably pushing out more than the driver's side and it's noticably warmer too. No visible fumes - just checked by hand/feel.
 

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Discussion Starter · #8 ·
Some really good explanations. Thank you.
So it's safe to say that most of the time only one valve will be open (drivers side I'm assuming on mine due to carbon build up) and steam will only come from one side.

It's only when you exceed 3000rpm that all 4 pipes of the exhaust outlet get used.

I know BMW use a similar system to quieten the cars driving around town.

I only ask as it can look to onlookers that it has fake outlets....

Edit: interesting that some have more smoke/steam coming from the passenger side and others more from the drivers-side...
 

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Pretty much - looking at the carbon build-up over the past 4 months there is much more on the right-hand side than the left-hand side, so that points towards much more exhaust gas being emitted by the right-hand tail pipes.

Does your TT have the vacuum hose for the exhaust? I'm not that familiar with the 2.0's setup :?
 

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Discussion Starter · #10 ·
How does one go about modifying the valve on the left hand side for it to stay open all the time?
Is it a fairly easy thing to do?
 

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Discussion Starter · #11 ·
Benw87 said:
Pretty much - looking at the carbon build-up over the past 4 months there is much more on the right-hand side than the left-hand side, so that points towards much more exhaust gas being emitted by the left-hand tail pipes.

Does your TT have the vacuum hose for the exhaust? I'm not that familiar with the 2.0's setup :?
I have no idea mate :-(
 

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Haven't had a go myself, but there must be a way of manipulating the valve so that it sticks open. Not sure...

Regarding the vacuum hose - I've got a small black rubber hose that emerges from the rear of the car and connects into the valve on the exhaust. Some members on the forum have described simply pulling the hose off then clamping it shut or tying it up, but I've not really looked at it closely to be honest (or not on my car anyway, just researched it online).
 

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only one side is the correct answer.
 

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Discussion Starter · #14 ·
Toshiba said:
only one side is the correct answer.
Care to elaborate on that Tosh.....
One side all the time......one side during certain rpm/load...etc...
 

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its the vacuum hose/sport button that controls distribution.
You can "block" the hose and keep the "flap" open. works the same as it did on the old MKI V6

Do a search and you'll see loads of post on the subject - this was the first on the list..
viewtopic.php?f=2&t=157118&p=1600244
 

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Discussion Starter · #16 ·
Cheers Tosh

I notice on the pics that there is a valve thingy looking type of gizmo on the left tailpipes which has a black cable coming from it. Does that cable run from the engine?
I don't have that as mine is not a TTS.
That suggests that mine must be in a closed state but saying that people who have done the "mod" have either pulled that cable out or made it useless by tieing it up so to keep the flap open all the time. So by that logic, my flap should, by default be open too (as there is no cable)?
 

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Needs a vacuum hose to open the flap.
So if its discounted then the flap will remain closed at all times. (ie only one side - pass working)
 

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Over here in SA, we commonly refer to it as a "flapper valve" - on my car i've noticed that it opens at precisely 3,500 rpm.

Toshiba, when you refer to the vacuum hose, are you referring to the hose leading from the DV plate to some sort of black cannister and then to an area just behind the dashboard? Always thought that this was a "noise pipe" like they had in the US Spec Golf V GTI?
 

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Discussion Starter · #19 ·
Toshiba said:
Needs a vacuum hose to open the flap.
So if its discounted then the flap will remain closed at all times. (ie only one side - pass working)
So i need to force it to open using a vacuum hose?
Will it remain open then or forced shut under pressure?
No doubt once its open it will increase the drown.
 
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