VNT and VGT turbochargers

MDCmotorsports

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#1
A few videos to start off with. I will go into detail later on why they are good and why they are bad.

[video=youtube;Gc2awh0O0Bc]http://www.youtube.com/watch?v=Gc2awh0O0Bc[/video]

[video=youtube;KgVrpiFfp8U]http://www.youtube.com/watch?v=KgVrpiFfp8U[/video]

[video=youtube;COl46Ph8XFo]http://www.youtube.com/watch?v=COl46Ph8XFo[/video]

[video=youtube;lXDFFH3K45g]http://www.youtube.com/watch?v=lXDFFH3K45g[/video]
 

tekdeus

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#2
Pretty cool. It's doing exactly what my SP quick spool valve is doing, only in a much more complicated way.
 

blk91

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#4
I think VNT is around 15 year old Tech that never cought on. To complex and the company that was making them folded. But I think it ended up in Porche 997s.....That were outperformed by conventional turbos in similar setups....GTR.
 

Nick 95 6sp

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#6
So what are the Cons to using one of these turbos?
I would say cost and reliability, and the added problem of how to control the vanes.

Since Porsche is doing it in their newest turbo 997's, I have to believe reliability is very good at least up to that power level. But it seems to me that when the Porsche's are built up to higher power levels, they swap out these turbos. I would like to get a couple of those to play with.

I know it could be controlled by Motec and probably also with AEM v2, some others too. When I looked into it before going with my two Garretts, the BV50 VTG turbo shown in the BW/Airwerks 2010 catalog went for over $3000 each and that doesn't include the controllers/actuators. Here's some comments I had, mainly from Geoff of FullRace:

Still researching twin turbos, I was looking through the new BW/AirWerks 2010 catalog now on Full-Race's website ...and I saw the BV50 VGT turbo is available...if you know of something available short of a Porsche ECU that can be used to control a couple of these on my twin manifold setup?
im sooo with you on that one... two of those on a 2jz would be omfg

AEM or Motec can control it... pwm output is all
Geoff,
I'm really sorry to hear you say that... ;)
...its probably more than what youre looking to do, but im REALLY interested in knowing what the BV50 would do on a 2JZ, it seems to me that 600whp is certainly possible, with a gargantuan powerband...
I have not heard of any failures, and my contacts at BW have not either (i asked them to send me some bad ones for mockup - they dont have any to send). It looks like the price may also be north of $3k/turbo as well.
Are the BW VNT turbos pneumatically controlled or electrically controlled?

If pneumatic, I am sure you can make a CO2 system with a boost control solenoid and AEMs boost control mapping work very nicely to properly control the turbo.
 

bloodasp90

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#7
now, how would these differ compaired to the holset HE351VGT turbos and how there vanes work and are controled?
 

MDCmotorsports

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#8
now, how would these differ compaired to the holset HE351VGT turbos and how there vanes work and are controled?
The Holset turbos use a "gate" of sorts that resembles a cone. It rises and falls in height to control the turbine speed, rather controlling veins. I think Holset calls it a nozzle.
 

8thsin

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#10
The holset he351ve can be controlled with an actuator (wastegate actuator) they take off the stock electronic box and Fab up a bracket to mount the actuator to the vanes collar. Run a vacuum line from the Turbo to the actuator and by trial and error set the spring pressure. As boost increases the collar will be pushed out. You can use a boost controller to fine tune as well
 

mtriples

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#12
So...to throw a little more feedback into the subject. I started wondering a while back, if people have just become too biased against VGT/VNT turbos, and figured I'd make the leap to see for myself with a modern variant.

I'm centering my build (MKIV, 2JZ, fully built engine, titan auto) around a Garrett GT3788va, modified to take a 68mm compressor wheel.

The GT3788va is an upgrade for the GT3782va found as stock equipment in the ~2006 6L Ford Powerstroke.

This model uses your oil pressure and a solenoid to actuate the vanes, using a PWM signal. A company called Fleece Performance makes a standalone controller that gives full tuning control over it. It will position the vanes based on TPS, engine speed, and boost. Limequat is also using this turbo in his 4.2L vortec I6 swap, but is trying to set up megasquirt for control.

As a side note, Fleece also makes controllers for the Holset applications, IIRC.

I cannot remember what exactly the PWM frequency is, but it is outside the range rated for the AEM EMS2's control, so I have no idea if it would be successful.

The 3" vband turbine inlet will also pose a problem for some people, as you'd probably have to modify your manifold or have a custom one made up.

Talking with Fleece, they have had good reliability with this turbo up to EGT's of 1400f, which shouldn't be a problem with good water/meth injection. The weak point is that once you go much higher, the tips of the vanes and the turbine wheel become too soft and start to bend from the force. I'll be running EGT feedback for fuel and wastegate trim, just in case.

I'll post more info up when I get a chance, and again when I get the car running this summer.
 
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mtriples

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#14
Not yet. The build rolled out of control as they tend to do, and I've added a huge amount of work to the plate since I made the previous post. Should have the car finished this summer, and I'll post up what happens.

Something that I'll mention though, is that the Fleece controller has been scrapped, since they won't rescale the output map to go over 3800 rpm. Instead, I'm controlling it directly with my ProEFI standalone.
 

yhatzee89

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#15
If you are using a version of the 6.0 PowerStroke turbo, try looking into getting a WickedWheel2, a lot of guys run them and love em. I own a 6.0 and the turbo does amazing on anything from gunning it at a stop light to cruising down the freeway at 90.