Mechanical VNT Turbo Vane Control

Upgrades to the 1.5, 1.6 and 1.9 engines that make them go farther or faster
libbybapa
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Re: Mechanical VNT Turbo Vane Control

Post by libbybapa »

I have no real firsthand experience with compounds, but I think that if your goal was more than 20psi efficiently then with an ideal compound system you could get better overall performance. If your goal is less than 20psi then there is no advantage to compounds over a single VNT and there are several downsides to compounds, most notably significantly increased fabrication, greater complexity, greater r+d and steeper learning curve. Because I'm more interested in longevity than I am in maxing out an engine, if seeking higher performance than an efficient 20 psi I would choose a different engine to start with rather than totally maxing out an engine with the complication of compounds.
vizion
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Re: Mechanical VNT Turbo Vane Control

Post by vizion »

Hi Andrew,

Just found out we're both in Arizona. I live in Gilbert.

I don't need to do compounds. It could break easier. Longevity and a little fun is good for me. Are you open to tuning engines ? I could take my 1.6-litre Jetta over there sometime. This is the non-turbo version though.

What's your phone # ?

Eric
libbybapa
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Re: Mechanical VNT Turbo Vane Control

Post by libbybapa »

Here are some design drawings of an updated design that eliminates the need for the spring in the linkage rod by always allowing the accelerator lever to return to idle regardless of vane position and boost can position. Notice the boost can is mounted directly to the transition lever instead of being part of the linkage rod and the angle of the boost can arm's motion is such that it always allows the return to idle and open vanes. I have not yet built one of this design and have waffled back and forth on whether I will pursue this design further or build up a standalone electronic version which would also be an interesting challenge.

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Fatmobile
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Location: north central Iowa

Re: Mechanical VNT Turbo Vane Control

Post by Fatmobile »

Thanks for sharing this.
I try to relate the vaned turbos to the waste gated turbos by calling it closed if all the gasses are going through the turbo, boost is max
and open when it is bypassing the turbo to limit boost.

You are using the opposite:
Calling it open when the lever is pushed down and boost is greater,..
and closed when the lever is pulled up and boost is reduced.

If so; I see that with no peddle the vanes are set for max boost, unlike your previous setup.

So max boost is available off line, and the backpressure isn't much at idle so shouldn't mess with fuel consumption.

So do I have this right?
In these drawings; vane lever pulled upward means less boost?
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
libbybapa
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Re: Mechanical VNT Turbo Vane Control

Post by libbybapa »

There are different designs of the VNT turbos. The integral manifold VNT15 as found on the ALH has the vanes closed when pushed down. The non-integral manifold VNT15 has the vanes in the closed position when pulled up. I drew the above drawings representing the latter.

Vanes open creates minimal boost. Vanes closed develops maximum boost and maximum back-pressure. In the drawings the vane lever DOWN is open (green line), UP is closed (red line). The only functional difference between this design and the previous one is that the boost can is moved to the transition lever and angled in such a way that regardless of manifold boost pressure, the vanes will return to the open position when the accelerator returns to the idle position without the need for the spring loaded linkage rod setup.

This first drawing shows the vane position when the accelerator lever is at idle and there is no manifold boost pressure. Vanes are in the open position.
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This next picture shows the geometry when the accelerator lever moves to the full load position but before boost has developed. Vanes are in the closed position and the boost can is in the relaxed position. With the vanes in this position, boost will rise very quickly but this 'snapshop' is before it does.
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This next drawing shows what will happen if the accelerator lever is held in the full load position and the boost rises so that the boost can is fully extended. The vanes are able to reach the fully closed position. In reality, the boost would be regulated by the can to the desired max boost and the vane lever would be somewhere between the fully closed and fully open position, but the drawing shows the full range of motion.
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This next drawing shows what would happen if one were at max boost and suddenly released the accelerator back to idle. The boost would still be at maximum, but the accelerator could still return to idle and the vanes would open almost completely in the process.
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libbybapa
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Re: Mechanical VNT Turbo Vane Control

Post by libbybapa »

This looks like it would work well as an adjustable boost can.

http://shopping.kinugawaturbo.com/kinug ... using.aspx
avocado
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Re: Mechanical VNT Turbo Vane Control

Post by avocado »

libbybapa wrote:I have too much going on right now to get to it. I'll keep you posted if I do, tho.
Please do. :D

Also: do you have a link to those photos?
Currently working on shoehorning a 1.6 TD out of a 1984 Jetta into a 1971 VW Camper (Hardtop)

"Huppity Hup! Rev! Rev! GO GO GO GO!"
PFunk242
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Re: Mechanical VNT Turbo Vane Control

Post by PFunk242 »

Are you still making these?? I am getting ready to put a vnt17 on my 1Z and would be extremely interested in one.

Thanks
Nanderdubfan
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Re: Mechanical VNT Turbo Vane Control

Post by Nanderdubfan »

I would love to see some of the pics in this thread. Currently trying to research a mechanical way to actuate the vanes on a vnt17.
Fatmobile
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Re: Mechanical VNT Turbo Vane Control

Post by Fatmobile »

You can check my VNT thread for pics.
Andrews was for a vanagon and the turbo he used had a lever that moved in the opposite direction as the common VNT-15.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
BGA
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Re: Mechanical VNT Turbo Vane Control

Post by BGA »

Libby wrote:
"Re: Mechanical VNT Turbo Vane Control
Post by libbybapa » Fri Dec 14, 2012 10:16 am

Here are some design drawings of an updated design that eliminates the need for the spring in the linkage rod by always allowing the accelerator lever to return to idle regardless of vane position and boost can position".

Pics are in ( I think) : http://s13.photobucket.com/user/libbyba ... t=3&page=1

Does he mean pics with white background (can with tangential moving) or the ones with black background ( can with axial moving, often seen in other control systems, Libby, Rock3tman) ?
Has the "tangential moving can ever been built? Result?
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