[condor]

Originally Posted by Carrera555

How do the vanes work?

For a simple analogy, Imagine a suction mechanism / vortex. Or a whirlpool in water. The water from outside travels in a circular motion towards the center.

Similarly, the air from the edges is pulled into the center. Since this is driven by the rotating compressor, the pull /suction increases with speed of the turbo charger. The higher the speed, the more the suction. During this process of getting sucked in, the air gets compressed

Note:
this is high-level. You will need to understand the flow of the air to understand how it is getting compressed

[a4anurag]

Hello All!

Was going through this thread and in a link that was attached found a few causes and remedies for a faulty turbo charger. This can be used to find any kind of problems related to it.









Searched the whole thread and could not find this so pasting it here for your help.

Hope its of any help!

Cheers,
Anurag.

[Sutripta]

Originally Posted by condor

Similarly, the air from the edges is pulled into the center. Since this is driven by the rotating compressor, the pull /suction increases with speed of the turbo charger. The higher the speed, the more the suction. During this process of getting sucked in, the air gets compressed

Hi,
Totally confused! Are we talking of the exhaust part or the intake?

Regards
Sutripta

[Carrera555]

Thanks 1self & Condor for the explanation.

That means the Vanes just redirect the exhaust gas which enters into the Turbo right in the center of the Turbine which helps it spool at low RPM's. Right?
BTW are those vanes fixed or they are just placed in such a way that it can move with the pressure of the exhaust gases?

[1self]

Carrera555, you are correct in that, there is an increased volume of exhaust gases flowing through the turbine due to the angle of the vanes. The pics I've posted earlier show that these vanes move depending on rpm & demand from the engine. It can be controlled either by the ECM (PWM signal) or a spring loaded actuator.

[AlphaKilo]

Originally Posted by Carrera555

Thanks 1self & Condor for the explanation.

That means the Vanes just redirect the exhaust gas which enters into the Turbo right in the center of the Turbine which helps it spool at low RPM's. Right?
BTW are those vanes fixed or they are just placed in such a way that it can move with the pressure of the exhaust gases?

Originally Posted by 1self

Carrera555, you are correct in that, there is an increased volume of exhaust gases flowing through the turbine due to the angle of the vanes. The pics I've posted earlier show that these vanes move depending on rpm & demand from the engine. It can be controlled either by the ECM (PWM signal) or a spring loaded actuator.

Adding to what carrera555 has said:

Inlet guide vanes are just guiding plates(directing blades) which are stationary and help direct the airflow to concentrate on the area where the compression takes place. Technically speaking, increases the mass flow concentration into the compression zone, and helps reduce spillage.
more info with good images:
http://av8rdas.wordpress.com/2011/09...ed-drivesbsds/
Google-Ergebnis für http://www.damper-designs.co.uk/ivc%20standard.jpg

[suhaas307]

Originally Posted by Carrera555

Thanks 1self & Condor for the explanation.

That means the Vanes just redirect the exhaust gas which enters into the Turbo right in the center of the Turbine which helps it spool at low RPM's. Right?
BTW are those vanes fixed or they are just placed in such a way that it can move with the pressure of the exhaust gases?

From what I have understood, a regular turbocharger comes with vanes that are fixed at an angle in the turbine. But in a VGT, the position of the vanes alter constantly, depending on the RPM.

The lower the RPM, the more 'closed' the vanes are. Basically, the gaps between the vanes reduce a great deal at lower RPMs in order to create resistance, when the exhaust gasses aren't sufficient enough to spool-up the turbo. So In a VGT, the vanes 'close' and leave a small area for the exhaust gasses to pass through at low RPMs, and as you hit the throttle and go faster, the force of the exhaust gasses increases, naturally, and that's when the actuator adjusts the vanes to allow for full flow of exhaust gasses through the vanes.

Please correct me if I'm wrong.

[Carrera555]

Lets put an end to most of your queries here. Just check this link out, its has some really detailed & informative pics & videos.

Turbocharger FAQ turbocharging exhaust

[SmartCat]

All modern diesel cars these days are equipped with a turbocharger. Read any review of a car equipped with a CRDi engine and it goes "There is a perceptible lag initially, but once the revs crosses 2000 RPM, the turbo kicks in and there is a massive shove and the car pulls like a train "

1) So what's with this 2000 RPM mark? Why does the magic power genie awaken the turbocharger only at those revs?

2) Is there a turbocharger that awakens at, say 1000 RPM? Can't some rechargeable batteries power turbocharger at lower RPMs, before letting the engine take over the duties at higher RPMs?

[kaush666]

I might be wrong but I guess the turbocharger requires a certain pressure before to be built up before the turbine can spin.

If a turbo spools at around 1k rpm as you say then the boost generated might not be much and there wouldn't be much of a bump in say torque as compared to a naturally aspirated engine.

Please correct me if I am wrong.

Cheers,
K

[Cesc]

Not qualified to speak on this but still guess I will ramble a bit. 900-1000 RPM is the engine idle on most cars so if a turbo has to start functioning then then it will have to 'wake up' pretty soon. AFAIK a turbo is supposed to assist the engine burn more fuel by supplying compressed air. The more power you demand from the engine the higher the turbo rpm (have heard they go up to 250k rpm even on humble cars) and more the air that flows in. The max air supplied depends on the turbine size among other things. A turbo may 'awake' around 2k rpm but I think it functions over a broad range and its revs rise with engine revs upto its peak capacity.

Why only 2k RPM? I will hazard a guess that below 2k RPM the engine can supply enough power/torque based on the normal air supply but needs assistance after that. You could have a turbo functioning below that range but then the peak turbo air supply will also come in sooner and your mid/top-end may suffer. Since most of our driving happens around 2k rev range it would make sense for a turbo to start functioning around that range. Didn't understand the rechargable bateries powering the turbo (I think the exhaust gases play a part in when it starts spooling) bit so can't ramble on that

[(Alok)]

Similar thread already exists………..

(http://www.team-bhp.com/forum/techni...gers-work.html)

[srishiva]

So, you would have a hybrid with a supercharger and turbocharger. It should be fine to have one. They already have twin turbo chargers.
But still you want it to kick in when required to not waste fuel around idle.

[reddream]

I feel a turbo can run at peak at any RPM. In case of heavy vehicle, the engine hardly runs above 1500 RPM, so the turbos are spooling at idle itself. If our cars start spooling early, then the RPM of the turbo will be too high too soon and can cease.
What it means is that a turbo works on a narrow band, and based on the size of the turbo vanes you can make it work at low rpm or higher.
In fact to control this size of the vane dynamically a VGT turbo is used.

Instead of battery, engines are known to use a supercharger at low rpm and make use of turbo at higher RPM. Like the Lancia Delta S4, Lancia Delta S4 - Wikipedia, the free encyclopedia

Also there are a number of modern cars now with this twincharging setup.

[a4anurag]

There is a specific amount of pressure from the exhaust gases that are needed to spool up the turbocharger. Since 1000 rpm is around idle for most engines it would not be safe to give the boost at such low range and considering efficiency too.

There would be need for launch control in all diesels because of the boost by the turbocharger.

Just a thought (I may be wrong too)

The vanes, shafts, casings etc are made in such way that it wakes up around 2000 rpm? since strength and reliabilty are main factors.