VNT Hybrid Setup - Largest Compressor Size Able To Fit?

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Fabia TDi

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VNT Hybrid Setup - Largest Compressor Wheel Able To Fit?

My first post in a long while.. :)
I'm talking about a VNT17 turbo with the turbine wheel integral with the exhaust manifold....
My understanding is that a hybrid (e.g Allard's VT2) uses the compressor wheel from the VNT20 Garrett turbo, housed in a modified VNT17 compressor housing.
So... would it be possible to fit an even bigger compressor wheel from an even larger VNT turbo while housing this inside the modified VNT17 compressor housing?
Pros and cons?
The normal obvious step up from the hybrid turbos seems to be VNT20 based units, but just wondering how far a hybrid set up can be taken.
Cheers.
 
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M

mojogoes

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I would think that what ever wheel is in the VT5 from Allard is about the max i've been told , the excess size and weight/inertia of a larger than VT5 may cause the shaft to brake.

The vnt17 housing maybe at its limits with the VT5 wheels already , which at this stage it would be a better decision to use a vnt20 any ways.
 
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Fabia TDi

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mojogoes said:
I would think that what ever wheel is in the VT5 from Allard is about the max i've been told , the excess size and weight/inertia of a larger than VT5 may cause the shaft to brake.
The vnt17 housing maybe at its limits with the VT5 wheels already , which at this stage it would be a better decision to use a vnt20 any ways.
Click to expand...
I had (maybe wrongly!) assumed that the VT5 is VNT20 based with modified internals, hence the need for a new exhaust manifold when fitting VT3 versions and above?

So the VT5 uses modified VNT17 compressor housing?
 
devonutopia

devonutopia

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Hi Matt. :D

I have absolutely no idea, but I adore the noise of the VT5. With my exhaust you get a permanent hushed exhaust whistle out the back, even just on tickover. It spools up very nicely considering I'm on a 16 month old map, and the noise on full chat. The exhaust actually BARKS - I never thought a TDI exhaust would bark, ever....
 
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Fabia TDi

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devonutopia said:
Hi Matt. :D

I have absolutely no idea, but I adore the noise of the VT5. With my exhaust you get a permanent hushed exhaust whistle out the back, even just on tickover. It spools up very nicely considering I'm on a 16 month old map, and the noise on full chat. The exhaust actually BARKS - I never thought a TDI exhaust would bark, ever....
Click to expand...
Hi Jason :D

Your setup sounds awsome.

Still deciding what to do myself! :rolleyes:
 
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Fabia TDi

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OK, so what I really want to know is what is the largest anyone has gone compressor/cold side of the turbo whilst retaining the standard VNT17 manifold integrated turbine on the hot side?
 
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Fabia TDi

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BlakGolf said:
kerma is supposed to come up with bigger turbos soon. im waiting for his call :)
Click to expand...


Do you know yet if these are VNT20 based requiring the new manifold as per current Kerma VNT20 upgrade or are they VNT17 hybrids?
 
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jthesby

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Fabia TDi said:
Do you know yet if these are VNT20 based requiring the new manifold as per current Kerma VNT20 upgrade or are they VNT17 hybrids?
Click to expand...
I would assume requiring the new manifold as the current kerma vnt20 upgrade... the exhaust side of the vnt-17 is so limiting, to cause excessive backpressure pre-turbo...higher temps and not as efficient would be my guess....
 
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BlakGolf

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whos industrial injection. well im building my own exhaust manifold. it wont be as nice as the one that dave (passangerperformance) makes but its ganna be a good manifold for years to come
 
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pdxgrease

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when i called them up years ago they seemed to know something about our turbos even though they do trucks mainly.
 
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Eck

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They did my 17/20 conversion about 1 year ago. They did a great job but neglected the VNT mechanism. I had to take it apart and get the clearance right for each vane. It wasn't moving freely. I had some additional work but that was it. With the 20 compressor housing, the gap to the heatshield to exhaust manifold is really tight already.
I assume a 17/22 might be the biggest you can go. The 20 housing has lots of aluminum left to open up to a 22 setup.
Shane from Ind. inj. would know. They were great to deal with and worth the money I spent.
 
KERMA

KERMA

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Blakgolf your turbo is ready. I lost your number...
 
KERMA

KERMA

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Fabia TDi said:
Do you know yet if these are VNT20 based requiring the new manifold as per current Kerma VNT20 upgrade or are they VNT17 hybrids?
Click to expand...
Yes, and yes, lots of options call me to discuss please.
 
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pdxgrease

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Naturally Kerma is the best option. TDI turbos are his focus and Industrial is mostly a dodge shop. Charlie is going to be the most knowledgable when it comes to all the iterations of tdi turbos.
 
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BlakGolf

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i dont know the exact spec but if i remember our convo right its ganna be a bit bigger then a vnt22. but im ganna talk to kerma again next week.

my baby is ganna RIPPPPPPPPPPPPPPPPPP this summer :p, stay tuned boys ed is ganna get some hard competition :p
 
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mojogoes

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I didn't mean the turbo spec which i know knowing you kerma will be top secret ;) , but his overall performance mods setup.
 
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BlakGolf

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i dont know but the car will be undertuned for this summer. or else ill be bending rods for sure. im getting the new biggest nozzles charlie will be selling. the new turbo, fmic, his new flashloarder this summer i will only run about 20psi. as soon as the rod group buy works out. ill get the tranporter pistons and go all out

if anyone has a 11mm pump laying around for cheap hit me up i need it asap
 
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