GT1749VA versus GT1749VB?

[david_594]

So anyone found the differences between these 2 turbos? They are both vnt17's, but slightly different at the same time.

I was trying to find out more about my 17 and came across a finnish wiki with a little bit of info and turbine sizes http://www.autowiki.fi/index.php/VAG_dieselturbot


VNT-15 and

GT1749V malleissa 33,5 mm intake

and

36,5 mm flight

Garrett GT1749VA, 35 mm intake

and

36,5 mm flight

Garrett GT1749VB, 37 mm intake

and

38,3 mm flight

So the VA has a slighly bigger wheel on the compressor side as compared to the vnt15. The VB has both a bigger compressor and exhaust wheel so it should flow better on the exhaust side compared to the VA? The VA should spool a little faster than the VB though correct?

Anyone have any thoughts on this or more info?

 

[shortysclimbin]

david,

from talk with jeff on my vnt turbo issues it looks like the va model is indeed faster spool up. the only problem is the intake wheel is not ment to go over a set psi range. 18+ The VB is designed to support higher boost levels. this is great info btw. now all we need to do is post vnt 20 info in this post and what a great turbo info page!

 

[diesel des]

The va is in the 130 pd stock running 19 psi. they are fine into the low 20psi range. 25 is a streatch

 

[shortysclimbin]

thanks for the correction on that. all this talk of turbos makes my head spin

 

[shortysclimbin]

thanks for the correction on that. all this talk of turbos makes my head spin

 

[Slave2school]

Ok, I've got a VNT-17 here now. I know the link on wikipedia says that the PD 130 and PD 140 share the same turbo and all VA's are the same right? I'm a bit confised as to the VA, VB, VM and such though. I really have and what can it support for boost? Another link I found is equally confusing and the magic pdf link has expired... http://www.seatcupra.net/forums/showthread.php?t=93280

*edited because I can read now

Found this interesting chart out here too http://www.honeywell.com/sites/servlet/com.merx.npoint.servlets.DocumentServlet?docid=D51D560CA-EE41-8E59-3C6E-970F8C24584F#search=%22GTB1749VM%22

I am trying to get to the bottom of this because when I purchsed this turbo I was told there would be no physical difference between it and the PD150 turbo (just that the suffix were for the different applications) I guess I took that line ha. That isn't looking to be the case if it is the same as the pd130 turbo now is it? I don't want to muddy names but I would like some sort of confirmation before I confront the vendor and ask for compensation.

Just measured the compressor wheel and it is 35mm has anyone actually measured the compressor wheel of the VNT-17VB here and give me 100% proof that the number on the wikipedia link are correct or not?

 

[TDIfreak]

That text in Wikipedia is mine, the measurement's are done by me so I'd have to say they are correct . I have lot's of grease on my hands from these particular turbo models .
The text is valid for Golf IV generation cars (all VAG).

Golf V family is another story, but if a particular turbo has the markings -VA or -VB I'd stick with the measurements above.

 

[mickyTDI]

That text in Wikipedia is mine, the measurement's are done by me so I'd have to say they are correct . I have lot's of grease on my hands from these particular turbo models .
The text is valid for Golf IV generation cars (all VAG).

Golf V family is another story, but if a particular turbo has the markings -VA or -VB I'd stick with the measurements above.

Physically on the outside both turbos look identicle, difference is all internal. TDIfreak what other differences are there in the turbo? Is it just the wheel diameters?

 

[mojogoes]

I think inducers and exducers also slightly different sizes.

 

[TDIfreak]

There are both VA and VB turbos with different kind of compressor housing outlets depending on which vehicle its meant for.
The wheels are as mentioned above. Differences only in comp inlet and turbine outlet.

 

[mickyTDI]

The PD130 and PD150 Golf both look identicle on the outside. they have same housings, the only way to tell is the VA or the VB will be stamped on it. The PD130 Passat has a different housing because of different turbo hosing positions etc.

 

[KERMA]

Not the only way, look at the inducer diameter.

 

[mickyTDI]

What part is the inducer?

 

[TDIfreak]

^Yes when they are bolted on, both VA and VB look exactly the same on a Golf IV.
But if you take the turbo intake pipe off, the diameter of the compressor inlet (=inducer) is bigger in VB.
Same way, turbine outlet or exducer is bigger in VB.

 

[mickyTDI]

^Yes when they are bolted on, both VA and VB look exactly the same on a Golf IV.
But if you take the turbo intake pipe off, the diameter of the compressor inlet (=inducer) is bigger in VB.
Same way, turbine outlet or exducer is bigger in VB.

Doesn't make sense because the hose for the inducer and exducer that fits is the same part for both turbos

 

[Nitrowolf]

As I recall, the VA wheel is made from... umm aluminum was it? and the VB was made out of titatium... thus allowing the higher boost pressures.

Max safe pressure for a VB is around 23PSI I think... but I've heard of them being pushed to 30 without them blowing up. I have no first hand experience with 30PSI though. Mine spikes to about 26 regularly without apparent issue.

 

[TDIfreak]

Doesn't make sense because the hose for the inducer and exducer that fits is the same part for both turbos

If you think of a turbomachine you find that the INSIDE diameter of the intake is what counts. I hope this clears things up and I'm sure your turbobuilder will show things in practise.

 

[mickyTDI]

If you think of a turbomachine you find that the INSIDE diameter of the intake is what counts. I hope this clears things up and I'm sure your turbobuilder will show things in practise.

Ah i see, so where the intake pipe that fits over the inducer on the 130 will be thicker than on the 150 turbo becasue it would be machined out more?
The exducer exit has to be the same though because the hose has to fit in a clip.

 

[KERMA]

As I recall, the VA wheel is made from... umm aluminum was it? and the VB was made out of titatium... thus allowing the higher boost pressures.

Max safe pressure for a VB is around 23PSI I think... but I've heard of them being pushed to 30 without them blowing up. I have no first hand experience with 30PSI though. Mine spikes to about 26 regularly without apparent issue.

I know from first hand experience that a vnt-17 doesn't like 30 psi at all. First time I tried 30 psi with a vnt-17, it gave up the ghost immediately.
IMO 23 psi is about the absolute limit for a vnt-17, and then only in the midrange, cut it back to 21 psi at high rpm. If you want your turbo to last a while...

 

[Nitrowolf]

Thanks for the info Kerma... I'll have to check where mine throttles back to psi wise at high rpms... I think it kicks back to about 21 psi.

What RPM range should it start dropping back the pressure?

 

[KERMA]

I'll have to see if I can find the compressor maps again.

 

[goodkingharry]

vnt-17VB

PM sent.

 

[joevat]

now all we need to do is post vnt 20 info in this post

ok i'll donate mine. vnt20 st3 turbo. MAN OH MAN does this thing ever spool like a bad Mutha F'er.
people who claim that the 20 doesnt spool fast just aint getting it. its not in the turbo, its in the tuning. and alligator knows how to set these things.

 

[SRHeer]

GT1749s

Hey TDImen,

I am learning a bit about turbos here so be patient any feedback is appreciated!

I am building up a mTDI AHU 98 Mk3 Jetta engine to put into like a 91 Mk2 Jetta.

My question is will the GT1749VB fit onto the Jetta exhaust and intake manifolds without modification? And or what is the largest turbo or turbos out there that I can fit onto the AHU without having to modify much?

Right now I have a 2.0L Land Rover pump with an 11m/head - and .216 Firad nozzles - so I am thinking that putting on the GT1749VB verses the VA will be an added benefit in that does it not spool a bit later and handle more boost in a higher part of rpm range than the GT1749VA? Is this technically correct?

Any suggestions are welcome!
Any one have or know of a VB or equivalent FS?
Stephen

 

[dieseleux]

Read that...
http://forums.tdiclub.com/showthread.php?t=249349&page=3

17VA are manifold less (Passat turbo TDI) and use AHU original manifold.
17VB have trouble with engine mount because 17VB are built-in with a manifold.
I you use original manifold with good adaptor plate, you put many differente turbo on your AHU with good succes.



Dieseleux

 

[cog]

aprt from moving the peak boost slighty further up the rev range i noticed very little difference between stock vnt15 spool up and vnt 17vb . the vb is still a very responsive turbo.
do not get worried about spool up time with the vb its not an issue

 

[bhodgkiss]

So what fouls on the Passat longitudinal AFN engine when attempting to mount a VB with integral manifold please? Does it simply not fit? Is the turbo clocked differenty?

 

[JFettig]

In talking to one of the guys doing tunes, he stated the VA runs 19psi stock (21-22psi tuned) and VB runs 22psi stock (24 tuned).

Bhodgkiss, the turbo does look clocked differently and the actuator is definitely a different angle.
Compare this(VB):
http://www.idparts.com/catalog/product_info.php?cPath=24_45&products_id=761
to this(VA):
http://forums.tdiclub.com/showthread.php?t=293320
You probably have a VNT15 on the same manifold as G60ing does but he has the 17VA installed on his.

Jon

 

[cog]

correct the vb holds more boost due to its titanium compressor in fact it can hold 25-26 psi but theres not much point going over 24 psi due to high exhaust manifold presures just cancelling out any performance from more boost.
so
va turbo max 21-22 psi
vb turbo max (efficient)24 psi

oh and by the way when they say the inducer is smaller on the va there not talking about the turbo outlet that you attch the pipe to as this is the same . there talking about the the inducer wheel inside the housing that is smaller on the va

 

[bhodgkiss]

is it possible to clock a vb turbo differently so it works on an AFN?
With clocking its just the relative angular orientation of inlet to outlet sides, and this can be set to any angle? Or not?