Whatever happened to VNT turbos?

[TType84]

i always heard amazing things about these wastegate-less turbos anytime they were mentioned..

I would be willing to bet a large sum of money that not one turbo buick has one of these types of turbos though.. why not?

Have the CRB and BB turbos rendered them obsolete?

I just thought about it today after seeing a picture of a new ford truck.. i think the new powerstroke diesels, and it was using one..

just wondered why no one uses them..

 

[UNGN]

Garrett has the patent on them. Other people have made them and Garrett has sued those companies before they went to market.

The money has to be there for garrett to go into production on it.

Garrett has spent a ton of money researching air bearings, which make no sense in automotive apps. Maybe that's where the VNT money has gone.

 

[Turbo231]

My car has one and I love it!
It's a VW Beetle!
It's a cool setup, I had to take it apart to see how it worked.
When I start the car in the morning you can hear a faint whine as the turbo spools up.
I have pictures of it too if any wants to see how they work

 

[turbo buicks]

what are VNT turbos?

turbo231, could you shoot me some pics? ih8mcdonalds@aol.com

 

[Red Canyonero]

The new 6.0L Powerstroke motor has one, FYI. I still wouldn't put one on a high performance gasoline engine yet though.

I know of a TurboBuick owner that tried a VNT turbo out

 

[Drthv8r]

Yep the new power stroke ford diesel has the VNT turbo. Ford's claiming an all new technology but most of us know better...LOL.

 

[machinegun]

VNT stand for variable nozzle turbo. The following link will give you a pic basic tutorial of their operation.

http://www.thedodgegarage.com/turbo_vnt_pictures.html

 

[TType84]

if youre too lazy to read that article, a short explanation (from what ive read in corky bell's book)

. no wastegate

. exhaust turbine is surrounded by adjustable vanes, which are shaped like an airplane wing

. they open and close similar to blinds on any window

. when closed they let the turbo spool up fast like a small turbo would, and then they can open to make sure the turbo doesnt run of out of steam on the big end.. the vanes also act like a wastegate i read..

pretty much, it seems the technology lets you run as big a wheel as you want on the compressor side, and you have an infinite amount of adjustability to spool that huge puppy, by adjusting the vanes on the exhaust side.

there is another variant that just has kind of a 2 in 1 exhaust housing i saw, once its spooled up it switches over to the bigger housing.. not sure if thats still called VNT or if that is something else...

in any case im sure one day i'll have a BB turbo so spooling wont matter

 

[TurboTR]

>in any case im sure one day i'll have a BB turbo so spooling wont matter

Don't buy into over-hyping of the BB turbos. They don't spool by themselves, they still require a properly sized exh hsg and converter, just like a std bearing turbo. They offer an incremental improvement in response, not an order of magnitude improvement.

VNT's are the sh*t IME. They aren't out on spark engine cars basically because there has been no OEM market lately. Garret does have a few out right now in diesel apps that would be suitable to adapting to a high perf GN on the exh side IMO. One has a wide open exh a/r of 1.8 and has a ~ T series size center section and about a p-trim size wheel stock. The other is larger frame, like PT88 size center section and has a 2.0 a/r wide open. The stock wheel is about q-trim size though, maybe a tenth larger. Put in a larger wheel and mate it to a PT91'ish compressor and it would easily rule the 8/7 sec GN world IMO These exh hsgs are big, bulky and heavy though.

TurboTR

 

[NICKG]

turbo231, is your car a new beetle?

i can tell you that i worked for vw, and if you have a new beetle, you have the only one with vnt. kkk never made a vnt turbo. the ony cars that had it were mopars that i know of(iroc rt, shelby's)

 

[gn4u2c]

go to the shelby dodge board everything you ever wanted to know about them there.

 

[1of1547]

Isn't the same set up that Shelby used on its CSX in the late 80's. It was supposed to be the hot set up at the time.

 

[Turbo231]

Mine is a new beetle!!!
And has a VNT!!
You need to go to VW tech school, the TDI beetle is a VNT turbo Diesel

1.9 litre 4-cylinder 90hp (A4 type) - used in various models available in Europe and North America from 1998 on, this gradually replaced the previous engine as the car models were changed. Within this document we will call this the A4 engine because the most common application is the A4-chassis Golf, Jetta, Bora, New Beetle, and various models from Seat and Skoda using the same chassis.
The injection system uses a distributor-type pump. The oil filter is a cartridge type, and sits in a vertical container on the front of the engine towards the left of the car. On cars with transverse engines, the air filter housing is at the left side of the engine compartment and the two black plastic pipes to the intercooler lead towards the right front corner - exactly the opposite of the arrangement used on the previous model.
On North American models, the turbocharger is a variable-vane type.
On European models, the turbocharger is a conventional wastegate type. The North American A4 engine is essentially a Euro 110hp A4 engine but with engine controls optimized for emissions rather than performance

The TDI has a huge following,
TDI Club

 

[UNGN]

I guess KKK got some out before the Allied Signal Lawyers slapped them with a restraining order. Hope it never breaks

 

[Turbo231]

All VW North American Diesels from 1998 on use the Garret/ Allied Signal VNT turbo. We even sent one to John Craig to have seals put in on the turbo off my friends car. Had a hard time getting parts but John did it up nice!! Even wanted to know if we wanted bigger wheels put in it while he had it apart.

P.S
I know another TDI owner that did put a bigger wheel on the compresser. It made it an evil beetle!

 

[UNGN]

Originally posted by UNGN
I guess KKK got some out before the Allied Signal Lawyers slapped them with a restraining order. Hope it never breaks

I was confused, garrett makes VW's turbochargers and the TDI ones are VNT.

 

[Turbo231]

Here is another link

] VNT VW

 

[NICKG]

i don't know about that

iv'e sen about 500 turbo's from all the tdi, 1.8t and they all use a wastegate and none were vnt(took some apart) i do know that the diesels are funny and what they have on them never seems to match with vw parts listings. how evere, all the replacement ones ive sold were not vnt. this is old technology anyway, they never really did much with these anyway, or inycars would have been using these, or porsche for that matter

 

[Turbo231]

On the center section in an actuator that looks like a wastegate. It's not!
It's the pneumatic actuator that moves the vanes in the turbo.

Picture

If you take the turbo apart you will notice that there is no bypass port for exhaust to flow through, boost control is achieved by changing the A/R of the turbine.