So I see this is coming in the new Porsche 911 and other high-end cars. I wonder how long it'll take for the technology to trickle down to everyday vehicles and the aftermarket. And could an EMU or similar even work with it for us?

http://www.turbos.bwauto.com/en/products/vtg.asp

One goal of a regulated turbine is to expand the usable flow rate range in practical applications while maintaining a high level of efficiency. To accomplish this, the turbine output is regulated by changing the inflow angle and inflow speed at the turbine wheel inlet. In the case of the VTG turbocharger from BorgWarner Turbo Systems this is achieved using guide vanes located in front of the turbine wheel.
When the guide vanes are in the closed position, the high circumferential components of the flow velocity and a steep enthalpy gradient lead to a high turbine output and therefore to a high charging pressure. When the guide vanes are in the fully open position, the turbine reaches its maximum flow rate and the velocity vector of the flow has a large centripetal component. The advantage of this type of output control over bypass control is that the entire exhaust mass flow is always directed through the turbine and can be converted to output.
The guide vanes adjustments can be controlled by a series of different pneumatic or electrical regulators.
BorgWarner Turbo Systems currently offers various sizes of turbochargers with variable turbine geometries for diesel engines in automobiles and light commercial vehicles. The sizes range from 1.2 liters to 3.2 liters of displacement per turbocharger. This corresponds to an engine output range of 50 kW to 180 kW per turbocharger.
The demands placed on turbochargers with variable turbine geometries have steadily increased in the past several years. Just a while ago a per liter output of 35 kW was sufficient, but now the current state of the art demands 50-58 kW/l. A per liter output of up to 65 kW can be reached with improved turbocharger technology.
As a result of these higher demands, the exhaust temperatures and pressure conditions in the exhaust system increases. BorgWarner Turbo Systems currently offers turbochargers with variable turbine geometries for exhaust temperatures up to 850°C. In the future there will be turbochargers with VTGs for diesel engines with exhaust temperatures up to 900°C. Refinement of the VTG technology for use at even higher exhaust temperatures will expand the possible range of applications to include gasoline engines.
The mechanical demands placed on a VTG in a commercial vehicle are significantly higher than those placed on one in a passenger car since the rotary vanes also need to function as a highly efficient motor brake. This is necessary since future commercial vehicle engines will always have a lower displacement and the exhaust flaps used today at the end of the exhaust pipe will just not be enough anymore. Furthermore, the variable turbine geometry will be used to control exhaust gas recirculation, especially in modern commercial vehicle engines. When this is done, the pressure in front of the turbine is regulated by the VTG so that there is a sufficiently large pressure difference between the exhaust gas side and the fresh gas side after the compressor. Only then will the exhaust be drawn into the inlet duct through an exhaust gas recirculation valve.
BorgWarner Turbo Systems also offers a wide spectrum of VTG turbochargers that will meet all demands for use in commercial vehicle engines.

 

I know several turbo manufacturers are ongoingly doing research on variable vane technologies. How long before they become more common place I don't know. I saw some pictures from an HKS prototype recently somewhere but can't seem to find them now.

 

Corky Bell talked about this in Maximum Boost. I can't wait for this to be common on turbos. It will definitely make lag and boost threshold a thing of the past.

 

It's been used on diesels for years. And there was one company trying to sell this to the public but it's very expensive.


http://www.hiperturbo.com/

 

All super cool technology. Very complex but super cool. I tend to stay away from complex systems myself. I don't like VTC on motors. I still think its great stuff though.

Anyone wanna venture how the vanes are controlled? Is it an automatic mechanical thing that happens as a result of pressure or does the turbo have to be controlled by a seperate control module?

 

honda is doing it in the new SUV

 

VNT was available on the 1989 Shelby CSX. VNT/VTG is awesome and when it becomes commonplace on aftermarket turbo systems it'll probably be basically the end of the low/mid/high rpm power compromises with the current aftermarket turbos.

From http://www.xmission.com/~dempsey/shelby/sheldod9.htm

 

Impressive stats...

 

A sort of low cost, yet effective way to essentially make a variable turbine setup.

http://www.speedshopthagard.com/proj...rbo/index.html

http://www.turbomustangs.com/smf/ind...?topic=45148.0

 

Very inovative. Helps it spool better for sure. I just wonder if that poses a big restriction up top.

 

If done right, you could do a valve similar to the one in the first link to spool it quick down low, then somewhere in the mid-range open it up for high end breathing. Depending on the size and how much boost you're running, its very possible to cause a large retriction up top.

Some of those Mustang guys welded half of theirs shut, which if your turbo is just grossly too large in the first place, isn't a bad idea... but if you want quicker spooling with good top end, I think a valve setup like that would do wonders.

The one on the Z seems a bit... weak. I don't think it would last too long due to the heat, but if a person used a better valve it should work well and last quite a while.

 

Who wants to venture that the new GT-R is going to have a variable twin turbo setup? It seems like their keeping it really under wraps. But the general consensus seems to be that all of the systems are going to be super state of the art. In the new SCC article they even suggested an AWD system that can bias torque from front to rear(old news by now) and side to side.(<OMG!) I would be really impressed if they tossed variable geometry GT30'ish sized turbos on there. Or if these systems can be perfected enough run monster turbos like GT40 sized with VGT systems. Zero boost lag and insane top end. Basically like putting an all aluminum ZZ502 that can rev into an import. OMG I have to stop brainstorming.