Under the bonnet.

[Shenanigans000]

Hello all.

 

Attached is a photo of a Fabia TSi engine (not my actual car, but the engine looks the same).

 

I'm very curious to what the three little pipes are that I've circled in red. I'm guessing they're part of the induction system, but in any event, what is their purpose?

 

Any thoughts?

 

Cheers.

[rum4mo]

To date 128 views and no postings, maybe everyone else is like me, not really willing to comment/guess/explain in case it causes a deluge of "you know nothing!"  - that was the first interesting thing that I noticed when I lifted the bonnet of my wife's August 2015 Polo back in August 2015, the 1.2TSI engines have that as well, so is "obviously" something to do with optimising the inlet tract under varying conditions - there you go, I've messed up and did what I said I would not do, ie I guessed!!

[AGFalco]

It's your 'Flux Capacitor' Sir.

 

 

 

I have one on mine as well. Don't think it works though.

 

Thanks AG Falco.

 

 

Edited 19 October, 2017 by AGFalco

[Damo]

there to generate turbulence in the airflow running into the inlet manifold?

If you look at the bottom of the picture, right at the grille, you can see the inlet pipe. The air runs through the airbox (and thus through the air filter), then past those 3 panpipes, then - I presume - into the inlet manifold.

As for 'why would you want turbulence in the air intake?', well, this is because when the fuel is injected into the cylinder, it will form an uneven mist. By introducing turbulent air into the cylinder, the clumps of fuel vapor get knocked around and spread out more evenly. This way, when Mr Spark comes along to the party, the fuel burn is more complete and effective, increasing power and reducing fuel consumption as a result of less unburnt fuel in the exhaust gases.

[P@ul]

2 hours ago, Damo said:

there to generate turbulence in the airflow running into the inlet manifold?

If you look at the bottom of the picture, right at the grille, you can see the inlet pipe. The air runs through the airbox (and thus through the air filter), then past those 3 panpipes, then - I presume - into the inlet manifold.

As for 'why would you want turbulence in the air intake?', well, this is because when the fuel is injected into the cylinder, it will form an uneven mist. By introducing turbulent air into the cylinder, the clumps of fuel vapor get knocked around and spread out more evenly. This way, when Mr Spark comes along to the party, the fuel burn is more complete and effective, increasing power and reducing fuel consumption as a result of less unburnt fuel in the exhaust gases.

 

It does not sound right to me.  Intake manifold is in in the front of the engine. Air gets sucked into air filter and goes through the turbo charger, which is mounted, on the back side. Turbo charger compresses air and sends it to the cylinders through the charge pipe which is slightly to the right in the picture. I doubt there is any turbulence left by the time it reaches intake manifold.

[Breezy_Pete]

My guess would be noise reduction measure.

[Damo]

No idea if it’s right...

 

Copied and pasted it from a google search  

[Ootohere]

It would take more than the the sweet playing of pan pipes to reduce the noise of those engines.

 

 

 

 

Edited 19 October, 2017 by Headinawayoffski

[OzFabia]

You could always block the pipes and see what happens. 

[Ootohere]

Or at least put a party balloon on one pipe for starters, or just do all 3.

[rum4mo]

12 hours ago, P@ul said:

 

It does not sound right to me.  Intake manifold is in in the front of the engine. Air gets sucked into air filter and goes through the turbo charger, which is mounted, on the back side. Turbo charger compresses air and sends it to the cylinders through the charge pipe which is slightly to the right in the picture. I doubt there is any turbulence left by the time it reaches intake manifold.

 

Incorrect, the OP is asking  question about the newer versions of these engines, turbo has moved to the back of these engines, 

 

Edit:-  at least this thread has started to get some answers, not sure about the flux capacitor as there is normally a value on capacitors, not sure about noise reduction as this engine has been designed to be a major noise generator especially on cold starts, that means that I'd back the induction air "turbulator" -  I seem to remember someone at work bodging up an air flow straighter using a couple of paint stirrers grafted together - that worked a bit until he discovered commercially available air flow straighteners they were needed on a complex cooling air system that found itself with no extra space and a need to take one delivery pipe and fan out to four with equal/similar air flows and temperature characteristics over the temperature range of about -60C to +85C - "similar" is a very flexible word!

Edited 20 October, 2017 by rum4mo

[KeithCheetham]

 Its to relieve pressure when the coils/spark plugs fail and the car backfires through its induction system, to stop the lid blowing off the airbox.  

[rum4mo]

Discovered while reading another thread, these "pipes" are referred as RESONANZKAMMERN which translates into Resonance Chambers. (well that was what a translation site says it means in English!)

 

Edit:- there is a lug at both ends of that assembly where it fixes into the induction tract - but I'll not be tempted to lever it off - yet!

Edited 23 October, 2017 by rum4mo

[Ootohere]

Not required in the 1.0TSI 3 Cylinder then, they can sound rorty / throaty without a set of pan pipes.

[LightRain]

Resonance chambers make the most sense. Someone in the design office did their CFD work and didn't like how the oscillating pressure waves in the intake behaved and came up with this solution to the problem.

[GeneralPurpose]

As said, those pipes are resonator pipes. The engine designers needed to tune the intake pressure wave to maximise performance while reducing noise. 

 

 

[rum4mo]

On ‎23‎/‎10‎/‎2017 at 10:32, Headinawayoffski said:

Not required in the 1.0TSI 3 Cylinder then, they can sound rorty / throaty without a set of pan pipes.

 

 

Hummm, I'd guess that someone in VW Group land has chosen to now hide that feature with a remodelled air cleaner assembly, seems to me that it looks like they could still exist but are now hidden! 

 

Edit:- plus the bonus of now having a TSI engine badge - just in case you had forgotten which type of engine was in there, maybe this comes back to Headinawayski's comment, ie the noise could make you think that there was a TDI engine in there!

Edited 24 October, 2017 by rum4mo

[Ootohere]

Good.  Shows they maybe spent more time on Engineering & R&D. 

 

So less need for revised / upgrading of hardware parts as was required with the 1.2 TSI's in Euro 6 spec. Now discontinued.

[Shenanigans000]

Right, well, after reading all of the above posts, I'm thinking they have to do with resonance.

 

Do we think it's possible that they were specifically engineered to bestow the motor with it's quite characteristic, "growly" sound? That would seem to be something the Italians would do, not the Germans.

 

Or maybe they are like an appendix: apparently useless, until you find out you need it.

 

I do wish they were Flux Capacitors though.

[Breezy_Pete]

To be sound enhancers as opposed to noise cancellers, I think they would have to be open at the outer ends, which I suspect they aren't. That would also eff up the filtration.

[LightRain]

11 minutes ago, Shenanigans000 said:

I'm thinking they have to do with resonance.

Do we think it's possible that they were specifically engineered to bestow the motor with it's quite characteristic, "growly" sound?

The resonance is relating to the pressure waves in the intake caused by the inertia/compression of the intake flow hitting/flowing through intake valves. Essentially behaving like an undamped spring and mass with an induced load. It's the same phenomenon as with musical resonance, but different purpose.

[Breezy_Pete]

^ So do you think it's primarily about smoothing pressure waves to reduce stresses on the turbo, and nothing to do with audible intake noise?

Edited 25 October, 2017 by Wino

[LightRain]

I would think so, performance first and if there is some acoustic niceness from the design, then that's a good bonus for them.

[Breezy_Pete]

Hehe. Surely that would be regulatory constraints first, cost second, performance third...

[LightRain]

Well, this is VAG we're talking about

Although you're probably right.