Who Here is Running a VNT17 on Their ALH?

My turbo may be original (309k) and may be on the way out. I'm debating either sticking with the Garrett VNT15 or upgrading to the VNT17. I have found several posts on the topic, but looking for first-hand accounts from you ALH owners. I'm not really doing it for the power - I prefer fuel efficiency, though it would be nice to have some added power too. Those of you who have upgraded, do you have any regrets on the upgrade?

Thanks!

The VNT17 is a better fit for a 1.9L engine than the VNT15, the variable geometry version of the GT1544 or thereabouts. Efficiency in terms of fuel efficiency is much much more dependent upon design properties of the long block (cylinder block + cylinder head + piston geometry) than it is about the turbocharger and it’s backpressure.

Paraphrasing one who works in the field, whether the canes are open or closed [to the stop screw], there is a negligible impact to volumetric efficiency. This property has a partial impact to fuel economy, to the tune of less than 5%. Reducing your compression ratio by a point to around 18.5:1 will drop your fuel economy by about 10%. New turbo, with or without a remap/tune, will not directly affect your economy. Using the air and more fuel with the go pedal is the only reason your loose fuel efficiency.

In other words.
You will not gain power, or loose efficiency by installing a VNT17 alone. That's due to your foot being in the accelerator.
A tune is required to gain any real power, and then nozzles to push it a bit, but then you're opening the bee hive and a lot more mods follow.

I run a VNT17, however, my vehicle is not stock. When it was close to stock(manual swap, unknown injectors, no tune), I didn't really notice any difference, maybe a little laggier. Not really noticeable, and, a little adjustment can pep things up a touch. Not without sacrificing fuel mileage, however.

I believe that the VNT17, from my research is thought to be a more robust turbo and running a stock tune would likely out last the vnt15 given it's properly maintained. This is why I chose one for my car.
Since, I've modified it with a Malone stage 3 tune, egr disappearing act, BMW cyclonic filter, Southbend stage 2dd/ single mass flywheel, BEW lift pump, and swapped it into a 1.8t. The 1.8t has all vr6 upgrades stock(larger brakes, upgraded lower pancake pipe, etc)
Getting ready for the 2 1/2" cat back to replace the gasser exhaust, and I am going to try the Wuzetem p205 nozzles when they arrive. I have been considering having them rated if a fairly local nozzle company/guru is interested.

Pulling a trailer across country I was 65 - 70mph averaging 42mpg, and running 70 - 75 to Florida and back to NC I was running 47mpg. I have had it up to 54mpg at one time(Ohio round trip from NC), and I believe I will again soon, with new injectors and calibration.
And I have no regrets.

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Go vnt17. You will not be disappointed.

I have a stock VNT15 on my Stage 1 tuned ALH Golf. It's a zippy little thang. Very fun for just a tune.... I LOVE MY VNT 15.

I helped my brother put a VNT17 on his car; he has a stage 4 tune, 1019 nozzles, 3 bar map.. I think hes still working some issues out. BUT>>>>>>>


Between the Stage 1 Tuned car with the 15 on it and the stage 4 tuned car with the vnt 17 on it...

ya want torque or high end power?

if you install the VNT17 alone, dont even bother. EVEN though they're about the same price new.... You need nozzles, a tune, a tune loader, 3 BAR map to get the vnt17 equipped engine to run like it's supposed too.....

Both cars are fun as h*ll!

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Anyways.. Just a thought. After driving a 17 and 15 equipped car both tuned I realized that the driving the car with the bigger turbo on it forces you to drive the car almost like its a gas motor vehicle.

With the VNT15+ St. 1 tune.... The low end power is ALL THERE right away, and it pulls harder than stock all the way up to 4K RPM.
You put the 17 on a stock engine, YOU WONT BE HAPPY........ Need to buy te supporting mods FIRST before the turbo.

I'm not really saying this or that. Just giving you objective obesrvations from someone(me) that has driven 2 different ALH cars with 15, and 17 VNT's.
My big issue with the VNT 17 is that with the supporting mods you always want to mash the pedal. Which gives you **** mileage(high 30's LOL)

But just know that if youre going with the bigger turbo.... Theres about $1,000 if not more in supporting mods you need to take advantage of that bigger turbo.

I'm not really sayig go with one or another. But a new VNT15 with a stage 1 tune, coming from a stock tune will make you very happy.

My Stage 1 tuned ALH still makes 50MPG on the highway its AMAZING.

Unless you have savings to dump into the car, buy the VNT 15 and do a stage 1 tune....

These cars arent meant to race, but they're certainly a blast to drive.

Thanks for all the responses! Definitely some more information to absorb and consider. I bought this car solely for fuel efficiency on a long daily commute, as well as on long road trips (12 hours or less typically). The longevity is a great benefit. I've had LS1 Trans Ams that run 12 seconds and still see 33 MPG highway, so any "power" from this car won't be on the same scale. If I do go with the VNT17 I'd have a Stage 2 tune and new clutch installed by the TDI Guru near me who is doing the work. He has done this before on several cars with good success. I'm looking at about $2500 +/- out the door for a VNT17 installed or $1100 out the door for the VNT15 installed (Tune is $350 if I want that as well).

I prefer the VNT-15 (tuned of course) on an ALH. More responsive, smokes less on tip-in, and makes good power. FE is so dependent on driving habits I think it's hard to say if one is better than the other.

IndigoBlueWagon said:

I prefer the VNT-15 (tuned of course) on an ALH. More responsive, smokes less on tip-in, and makes good power. FE is so dependent on driving habits I think it's hard to say if one is better than the other.

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That's kind of what I was debating on in the first place until I saw the VNT17's on sale at ID Parts and others. I still like the idea of a tune with a new VNT15!

Another random question: If I want some more turbo sound, are there modified VNT15's that have different fins or something to produce some more whistle? I know it's not beneficial at all, but I love the sound of a turbo.

the stock vnt15 is one of the most "whistly" turbos I have ever heard. My jetta with a true straight pipe sounds like a jet at low engine speeds.

Deleting the CAT or muffler will give you more whistle. And VNT-17s don't whistle.

IndigoBlueWagon said:

Deleting the CAT or muffler will give you more whistle. And VNT-17s don't whistle.

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They sound better than the whistle IMHO, it drives me nuts to hear a diesel truck whistle through downtown on a busy evening.
I prefer stealth performance, the kind that at 80 it still puts me in my seat. No body else really needs to know what I have, just makes them want to steal it, or salivate over it at minimum.


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Gangles said:

Thanks for all the responses! Definitely some more information to absorb and consider. I bought this car solely for fuel efficiency on a long daily commute, as well as on long road trips (12 hours or less typically). The longevity is a great benefit. I've had LS1 Trans Ams that run 12 seconds and still see 33 MPG highway, so any "power" from this car won't be on the same scale. If I do go with the VNT17 I'd have a Stage 2 tune and new clutch installed by the TDI Guru near me who is doing the work. He has done this before on several cars with good success. I'm looking at about $2500 +/- out the door for a VNT17 installed or $1100 out the door for the VNT15 installed (Tune is $350 if I want that as well).

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If you want mileage you should definitely keep the vnt15, upgrade the nozzles and get a tune to match.
When were the injector nozzles changed last? Nozzles are a wear item and something you want to consider before a tune. Not saying you should install huge injectors, however, a larger Injector that would improve efficiency with less wear over time at the requested fueling. Bad nozzles can burn up a piston, or cylinder wall causing horrible results.

In the end good upgraded nozzles, new vnt15, and a good stage 1- 1.5 tune would be the best way to give yourself more power and maintain efficiency.

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I'd keep to a vnt15 unless you want the additional power of the vnt17 on a stage 4 setup, the smaller turbo will spool faster.

I used to have a Stage 3 tune with .205 nozzles and a VNT-15, and got excellent FE city or highway. I now have a 17/56 running a modified VNT-15 cold side, and although the Stage 4, 22 PSI tune is a lot of fun I seldom use all that power and miss the exceptional FE.

BW vnt17

OP, I have a brand new in box Borg Warner vnt17 on my shelf with a new gates clip connector hose, new stainless oil feed line and all supporting installation hardware available if you are interested. I never ended up installing it, still running the stock vnt15. PM me if you like.

Info on the turbo can be found at the link below from where I bough this kit.

https://www.cascadegerman.com/product/54399880083/

Regards,
Vin

Nevada_TDI said:

I used to have a Stage 3 tune with .205 nozzles and a VNT-15, and got excellent FE city or highway. I now have a 17/56 running a modified VNT-15 cold side, and although the Stage 4, 22 PSI tune is a lot of fun I seldom use all that power and miss the exceptional FE.

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HI,

Just curious BUT if you drove the 17/56 for economy how many MPG's would you get VS when you have the VNT 15 (assuming you drove them both conservatively) ? What Injectors are you running with the 17/56 ?

Thanks

Andrew

Andrew,
You got me: I failed to say I currently am running .216's set up by Frank.
The Stage 3 tune I was running back then that produced such great FE has been reborn; I had my tuner re-linearize the tune to work with a 3bar MAP sensor, so I now get 22 PSI or so at WOT. I do not have new logs but I used a boost gauge one day just to ballpark it.
My mixed MPG 90% or so in town was 38 and not always driving like Grandma, and she was still a bit sooty, so I raised the I.Q. from 4.5 to 6.5. This was kind of a random guess as the tune was calibrated for .205's. I do not notice any loss in performance, and I see less haze out the back window. If I bash the throttle in first gear, the tires break loose and if I grab second real quick, the tires are still spinning loose. So this new tank of fuel will not be 95% Grandma and when I get to 250 or so miles I will check the FE again, like I did the last tank. Who knows, I may adjust the IQ again? I will keep you all informed.

I put a VNT17 on a stock ALH. It is trivially softer down low, but it pulls a wee bit harder on top. I'd do it again without a second thought. My BEW will likely get one when its due a new turbo. I have no issue with it being slightly softer down low; pulling it hard down low is not good for DMF flywheels( it has a 17-050 behind it.
cheers,
Douglas

Nevada_TDI said:

You got me: I failed to say I currently am running .216's set up by Frank.
The Stage 3 tune I was running back then that produced such great FE has been reborn; I had my tuner re-linearize the tune to work with a 3bar MAP sensor, so I now get 22 PSI or so at WOT. I do not have new logs but I used a boost gauge one day just to ballpark it.
My mixed MPG 90% or so in town was 38 and not always driving like Grandma, and she was still a bit sooty, so I raised the I.Q. from 4.5 to 6.5. This was kind of a random guess as the tune was calibrated for .205's. I do not notice any loss in performance, and I see less haze out the back window. If I bash the throttle in first gear, the tires break loose and if I grab second real quick, the tires are still spinning loose. So this new tank of fuel will not be 95% Grandma and when I get to 250 or so miles I will check the FE again, like I did the last tank. Who knows, I may adjust the IQ again? I will keep you all informed.

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I find this post somewhat ironic: I can count on my thumbs (leaving out track days) that I've achieved less than 40 MPG in my Wagon. People do get good FE with VNT-17s, but I'd be unhappy with 39 MPG. I think because it spools up faster and uses more of the available fuel, an ALH with a 15 may do better than one with a 17. I've not seen below 48 MPG in my Wagon for a long time.

By raising the IQ I do not seem to have lost any power, so a couple of hundred miles from now I will check the FE again.

Just food for thought... my gtd1752vrk gets the exact same fuel economy as my vnt15 did, with the exact same spool. Actually it’s better off the line.
But it is pricey and you will need a tune, .216s and a 4bar map.

Judson said:

Just food for thought... my gtd1752vrk gets the exact same fuel economy as my vnt15 did, with the exact same spool. Actually it’s better off the line.
But it is pricey and you will need a tune, .216s and a 4bar map.

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HI,

I have heard that a larger turbo can get better mpg's at highway cruise (due to I guess less restriction through the turbine side of things).

I know you said exact same MPGs but was that mixed driving ?

Any direct comparison on highway VS highway mileage? (mainly that is what I drive)

I ask because I'd love to go bigger too (yours may be the ideal but I know somewhat larger $$).

Thanks

Andrew

Based on normal driving habits, which is mixed driving, measured over a full tank as usual. I have been tracking by hand my mpg since purchasing the car back in 2001.
If you haven’t already added a better, stronger clutch you’ll need to do that as well.