VTG turbos in the new 911....
#1
VTG turbos in the new 911....
got my road and track in today and was reading on the new porsche 911 turbo. it has VTG variable turbo geometry. which is adjusting blades surrouding the turbine wheel that optimize the exhaust flow on the wheel. it changes the responce and torque quite a bit. the 05 911 has 415 lb-ft at 2700 rpms. the new 911 with this turbo setup has 457 lb-ft at 1950 rpms. now it also says that diesels have been using this technology since the 90's. why arnt any turbo makers moving onto this setup? it makes turbo lag almost non existant. anyone else hear of these types of turbos?
#6
Rotor Head Extreme
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WOW that animation is pretty cool. That's exactly what a 13b needs. Also just imagin that technology on a GT42r . I wonder how long before other manufacturers adapt to this same technology or something similar. You know that turbo has got 50 thousand patents. LOL
Last edited by t-von; 04-06-06 at 01:09 AM.
#7
That stuff has been around since the mid 80's i think some of the audies or something use to use them, they never went any where, i think the design is a little complex.
CJG
CJG
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#8
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I lookied into this when I was in college before, and I spoke with some engineers from Garrett about it. The biggest reason they aren't on rotaries is due to the very high EGT's. The vanes that adjust the angle of attack to the turbine can seize up if the EGT gets too high. This could then create the problem of overboosting very easily.
#12
Rotor Head Extreme
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Originally Posted by efiniracer
I lookied into this when I was in college before, and I spoke with some engineers from Garrett about it. The biggest reason they aren't on rotaries is due to the very high EGT's. The vanes that adjust the angle of attack to the turbine can seize up if the EGT gets too high. This could then create the problem of overboosting very easily.
To me this is like that old debate to use sythetic in rotary's. With the tech available today, why not use Inconel for certain parts in the turbine section to overcome the heat related issues? Sure it would be a little more expensive, but I think these can be made to handle rotary's.
#14
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Originally Posted by t-von
To me this is like that old debate to use sythetic in rotary's. With the tech available today, why not use Inconel for certain parts in the turbine section to overcome the heat related issues? Sure it would be a little more expensive, but I think these can be made to handle rotary's.
I think that you have to look at the tolerances. In the area where the vanes are, you want all of the exhaust energy to go where the vanes direct it to go. If there is too much of a gap, some of the exhaust will "slip" past and do it's own thing. At which point it will not impact the turbine the way that the vanes are directing the majority of the flow. So now we are creating vortices and swirls in an area where we are looking for as laminar a flow as possible.
Everything expands as it contracts. The hotter it gets, the more expansion. So if they can bring the tolerances in a little bit tighter by limiting the EGT's that this turbo can handle, they can produce a turbo that will appeal to the masses. Unfortunately, rotaries are not as massive as we would all hope and we are a very small demographic to consider.
This is kinda off topic, but a friend of mine sent me a thread from a big-block type forum, and someone posed a very interesting question: "Where would the rotary be today, if it had one tenth of the development and resources that are normally allocated for say, the Chevy 350?" Very good question indeed. I think that I remeber reading that the engine development for the Renesis was done by a handful of Engineers in their spare time. They loved the engine so much that they didn't want to see it tucked away in the archives of what once was. It may not be the most powerful, desireable, or serviceable, but I think that we owe a debt of gratitude to those that helped keep the trochoid alive. This way we can look toward the future as well as the past. If you read this far, thank you.
#16
20B FD|20B Cosmo|S5 TII
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I took apart one of these about 2 weeks ago. It was/is a prototype for a diesel company. Very cool stuff. Pain in the *** to take apart (didn't have a large selection of tools)
I work for a Ceramic Coatings company, and in the very near future we have a coating coming out that may be useful with this technology. Bell Helicopters, and some folks at a government agency tested it 3rd party for us. We've already published stuff on it, so i can finally mention it. I am not allowed the specifics of it yet, but i think in the next week or so i will be allowed more info. Obviously the proprietary stuff i can't talk about, but i'll share what i can with you guys.
I work for a Ceramic Coatings company, and in the very near future we have a coating coming out that may be useful with this technology. Bell Helicopters, and some folks at a government agency tested it 3rd party for us. We've already published stuff on it, so i can finally mention it. I am not allowed the specifics of it yet, but i think in the next week or so i will be allowed more info. Obviously the proprietary stuff i can't talk about, but i'll share what i can with you guys.
#20
Respecognize!
#21
Originally Posted by Low Impedance
does it come with the sprite can?
I need to have a manifold constructed (it is a T6 turbine inlet, with a ~5" V-band outlet) in order to test out just how streetable it is. My past experience with VGT's has yielded that they are exceptionally streetable.
The vanes can close down nearly all the way, which not only provides more constant energy for the turbine wheel, but also very effective sound pressure level control
#23
#24
Senior Member
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Originally Posted by VGT
I need to have a manifold constructed (it is a T6 turbine inlet, with a ~5" V-band outlet) in order to test out just how streetable it is. My past experience with VGT's has yielded that they are exceptionally streetable.