Xman GT1752 Turbo

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
Back in June I installed a GT1752v turbo which I sourced from XMan Turbos in the UK. XMan calls this turbo a VNT 17/26 and claims that it is a hybrid turbo that uses the VNT-17 turbine and a custom 52mm compressor.

This is also one of the turbos XMan sells that is a direct fit to the ALH engine. All of the hoses, piping, oil lines, etc are a direct fit. The install took about three hours and I chose to do the "up and out" method of removing and replacing the turbo. That is I removed the intake manifold from the engine, removed the exhaust downpipe and compressor and intake pipes, undid the oil return line, and then lifted the turbo/manifold out through the top of the engine bay. Despite being a bit intimidating it was not a difficult process at all. The trickiest part is the oil return line but it is doable without too much fuss.

When first installed I was still running a Malone 1.5 tune which limited boost to 15psi. There was a noticeable increase in lag but nothing that couldn't be driven. Maybe the biggest change, and one i was told about prior, is that the familiar whistle of the VNT-15 is now gone. I kinda liked it and now miss it LOL. Because this was the same boost and the same fueling as before I didn't really notice much of a difference in driving short of the lag.

I ordered a Malone Stage 5 and a 3 bar map to go with it. Once installed and uploaded the car drives much stronger on the highway. I am seeing a sustained 26PSI without any spikes or noticeable boost creep. There is not a lot of smoke but rather a haze that is really only visible when backlit by sunset or headlights. But I won't say that it is other worldly. I can certainly tell that there is more power at the top end of the RPM range, which for highway driving in LA is where I need it. However, this combo of nozzle, tune, and turbo are not throwing me back into my seat as I had kinda hoped. The car is more powerful. Lane changing and passing is more assertive, but it still feels a bit meh. I do want to put the car on the dyno and see what the numbers are.

Anyway, just wanted to share my experience so far. and perhaps turn this thread into another long term test of these components.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Back in June I installed a GT1752v turbo which I sourced from XMan Turbos in the UK. XMan calls this turbo a VNT 17/26 and claims that it is a hybrid turbo that uses the VNT-17 turbine and a custom 52mm compressor.

This is also one of the turbos XMan sells that is a direct fit to the ALH engine. All of the hoses, piping, oil lines, etc are a direct fit. The install took about three hours and I chose to do the "up and out" method of removing and replacing the turbo. That is I removed the intake manifold from the engine, removed the exhaust downpipe and compressor and intake pipes, undid the oil return line, and then lifted the turbo/manifold out through the top of the engine bay. Despite being a bit intimidating it was not a difficult process at all. The trickiest part is the oil return line but it is doable without too much fuss.

When first installed I was still running a Malone 1.5 tune which limited boost to 15psi. There was a noticeable increase in lag but nothing that couldn't be driven. Maybe the biggest change, and one i was told about prior, is that the familiar whistle of the VNT-15 is now gone. I kinda liked it and now miss it LOL. Because this was the same boost and the same fueling as before I didn't really notice much of a difference in driving short of the lag.

I ordered a Malone Stage 5 and a 3 bar map to go with it. Once installed and uploaded the car drives much stronger on the highway. I am seeing a sustained 26PSI without any spikes or noticeable boost creep. There is not a lot of smoke but rather a haze that is really only visible when backlit by sunset or headlights. But I won't say that it is other worldly. I can certainly tell that there is more power at the top end of the RPM range, which for highway driving in LA is where I need it. However, this combo of nozzle, tune, and turbo are not throwing me back into my seat as I had kinda hoped. The car is more powerful. Lane changing and passing is more assertive, but it still feels a bit meh. I do want to put the car on the dyno and see what the numbers are.

Anyway, just wanted to share my experience so far. and perhaps turn this thread into another long term test of these components.
It's not the hardware's fault, it's the tune's fault. That combo has a lot more potential. You didn't mention what clutch you're running either.
 

fatmobile

Veteran Member
Joined
Jul 16, 2019
Location
north iowa
TDI
an ALH M-TDI in a MK2, a 2000 Jetta, 2003 wagon
Knowing the EGTs will tell you much about the air is matched to the fuel quantity.
Sorry to hear about the lower turbo whine,.. maybe it will come back as the turbo wears.
I've noticed my old VNT-15s sound better than the fresh ones.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
well, you know what to do :p take some logs, ideally log a whole trip somewhere: 011+001, 011+001+004. if it's a regular MAF tune, also 011+001+003. and then one log for boost control only 011. logging only a couple pulls, while helpful of course, don't show the whole picture very well. when logging >1 measuring block, it's important to get long (5+ second at least) throttle positions at various rpm ranges because the sample rate is so low on these ecus. see what sort of EGTs you get for cruising between 60 - 85mph as well as WOT and say 80% throttle pulls.

26psi with 11mm + .230s should definitely be putting you back in your seat. i'd be willing to bet the timing is too advanced for the fueling/boost ;)
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
It’s been months since I updated this so my apologies if it is lengthy.

after driving this setup for a while, and receiving and updated tune from Malone, I was still not satisfied with the car’s performance. I kept reading about how similar setups were measurably more powerful. Enter a conversations with Burpod. Initially he was just curious about logging some drive time as he was genuinely curious about why my car wasn’t performing as I thought it should. So we did that. I pulled a couple of logs and sent them his way.

in the meantime I kept driving the car and was just generally bummed that after a bunch of work and parts that this car still felt kind of dull.

After continued discussions with Burpod, I decided it was worth an experiment to see if together we could make this car drive the way others were describing. I purchased an MPPS V18 dongle and loaded it’s included software.

Burpod sent to me a tune he had created which was based on similar setups to mine.

Immediate difference

we started with a tune that was low on boost but that the timing and qty were very different than my prior tune. There were also key differences in how the ecm saw and used the components installed in the car.

while not wildly more powerful initially, gone was that heavy and gutless feel. I no longer felt like I was pushing the car down the road. Rather, it was like the car just wanted to keep pulling.

we worked together, me driving and pulling logs, and Burpod (during what must have been the middle of the night) would then take the data, make adjustments, send to me a new file, which I would then flash the next morning before driving and logging again.

All told we’ve exchanged dozens of data logs and several about a dozen tune files. If there was a way to see how many times this ecm has been flashed I might wager this one is a league leader in that stat!

So where are we now? We have dialed in something that is easy to start, very easy to drive, and isn’t feeling like the car or engine are being forced to move. Acceleration is smooth and the engine revs much more freely. I have to often look at the tach and speedometer as my muscle memory for throttle position now has me accelerated beyond 80 whereas it used to just have me cruising at 65.

We also identified a couple shortcomings in my hardware. I need a different intake pipe. I need a better exhaust system. I need a better/bigger Intercooler. But I do now have very nearly what I thought this car could be with this setup.

Now, I won’t tell you that we turned this thing into a world beater, not with this hardware. Going up an on-ramp last night a clapped out M3 walked away from me. But outrunning everything on the road wasn’t the intent. I wanted my old Jetta to be fun to drive and it is. I also don’t feel like I’m an impediment to traffic. I can pass whenever I feel like it, and hitting 100mph is effortless.

We do still have some work to do together but this whole project is about to shift into long term and efficiency testing.

If you are like me and just not quite happy with how your car feels I do encourage you to reach out to Burpod. I’m very happy he pinged me and offered assistance.

More to follow.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Great report! His tuning is a world of difference.

I have to say though, your ECM is just a baby compared to mine:)

I've flashed mine probably into triple digits (or close) with his tunes for my car (min of 1 log per tune sent back to him, sometimes 2 or 3). As well as bricked and recovered the ECM 3x.

Still in the fine tuning phase for mine after we noticed some differences between the OEM and Pierburg aftermarket n75 valves. Little things can really make a difference. It's a wild journey though and now we have someone doing it right that cares about the car's health as well as getting the most out of it!
 

dhangejr

Veteran Member
Joined
Mar 1, 2017
Location
PNW is my home
TDI
mk4 Jetta
My BEW is really laggy with full bolt ons including the 17/26 turbo. I thought it was the euro jet FMIC or maybe the budget stage 2 cam; but I’m hoping with some help from TDI live it will change. Burpod is really knowledgeable and has steered me in the right direction too. Just wanted to say that.
 

JohnB

Member
Joined
Sep 28, 2018
Location
Michigan
TDI
2003 Golf TDI GLS ALH 1.9T
My BEW is really laggy with full bolt ons including the 17/26 turbo. I thought it was the euro jet FMIC or maybe the budget stage 2 cam; but I’m hoping with some help from TDI live it will change. Burpod is really knowledgeable and has steered me in the right direction too. Just wanted to say that.
Interesting thread.

For reference I have an 03 Golf TDI ALH w/ the following setup:


Stage 4 Malone tune
VNT 17 Turbo (24-28PSI)
3BAR MAP
2.5" Buzzken straight pipe w/ resonator
PP 520 Injectors
Stage 2 Southbend daily clutch
EGR delete.
Stock cam

It pulls strong all the way to its gearing limit of around 135MPH

Heres a sample log file of the boost values on my car for reference. Would be neat to see any others setups showing 011 LOG from VAG-COM

https://log.tunezilla.com/chart/657...hP8KvwoZbwr/DmEbCoXPCn8OzB8Ksw7jCh8OFwqgAAAA=

In general what I have learned(which is somewhat obvious) is the bigger the turbo the more lag with these TDIs... I personally think the VNT17 is a good sweet spot. My brother also had installed one of the Hybrid 17/22 turbos and he had nothing but lag problems with it. The head ended up dropping a lifter before the tune was ever fully sorted out unfortunately.


Now, I won’t tell you that we turned this thing into a world beater, not with this hardware. Going up an on-ramp last night a clapped out M3 walked away from me. But outrunning everything on the road wasn’t the intent. I wanted my old Jetta to be fun to drive and it is. I also don’t feel like I’m an impediment to traffic. I can pass whenever I feel like it, and hitting 100mph is effortless.
Good to hear you at least are having more fun with it and got things dialed in more.

Even though we may not be pushing crazy power numbers in our TDIs, its still an amazing balance of fun and practicality. I would be in jail if I had a faster car anyway lol.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
if it's tuned well, the 1752 won't have any noticeable lag over a 17, and a 17 should have zero lag compared to a 15 :) even an old gen 1856 (just a size up from the 1752 - just with gt18 exhaust wheel + size up compressor) shouldn't have anything that's really noticeable. maybe a little bit below 2000rpm but not much.
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
Hey, all! I just wanted to give a bit more details on the work burpod and myself have been doing with this project, and also to go through a few of the things we noticed between the tune I had and where we are now.

When I left off I had detailed that we found some issues with my hardware; basically that I need more appropriate parts. However, we did identify some issues with the original aftermarket tune (and its update), and I wanted to share that with you here. This way you all can learn from us!

The aftermarket tune I had in the car was had overly advanced timing at nearly every power setting. So much so that the engine was essentially fighting against compression and ignition. The best I can compare it to the feeling a gasoline engine experiences when one is right on the edge of detonation. This lead to the car feeling heavy and unresponsive, and surely didn't help with efficiency either.

As burpod and I began to work forward on this project, he supplied me with three different tunes that could be switched via coding in VCDS (that's a really cool way to tune by the way). Each tune was designed to test key metrics of the engine without risk of damaging anything. The initial tunes limited boost and fueling to be sure we wouldn't break anything. After analyzing how the engine, turbo, and fuel systems were behaving we then (and only then) began to introduce greater fuel and boost amounts.

I just want to clarify that this was in no way a "hunt and peck" sort of tuning. We were not just throwing random maps at the engine to see what would happen. We discussed what we were seeing in the data and then briefing specific test criteria that I was to pull from the car (within reason as all of my testing was done on the road).

As I mentioned, my car does not have the best foundation for being highly tuned. I do need to upgrade intake, intercooler, and exhaust systems to really bring this thing into its own. Right now my IAT is getting far too hot under 2.6 bar, which is causing some loss of potential power. However, even with this issue, the car is much more powerful than with the aftermarket tune I had under every operating condition.

We are now moving into the efficiency and drivability portion of the testing. The "can I live with this" part. So real world driving rather than data logging, and also monitoring temps (IAT and Turbine Inlet). I still have three different tunes to test and I'd like to give each one a week before switching to another. Maybe two weeks to get a real good idea about the MPG.

I think this get's us up to this point. I may have forgotten something or left out some key data. If there are any questions please feel free to drop them in here.
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
if it's tuned well, the 1752 won't have any noticeable lag over a 17, and a 17 should have zero lag compared to a 15 :)
Agreed. The 1752 I have does not lag. In fact, it seems to respond incredibly well to the commanded boost, does not spike (drastically) and does not undershoot.
 

yeahkkyle

Well-known member
Joined
Oct 23, 2016
Location
Elysburg, PA
TDI
2003 Jetta 5 speed
Hope you don't mind me commenting on your thread but my experience has been exactly as you described (better than I could). I've also been working with @burpod and hope your quest for "daily drivability" is goes smooth. It is hard to keep your right foot out of it for an entire tank;). I will report prior to installing dlc520's and tuning I would average 43-45 mpg during the winter in PA and my last 2 tanks were 50.7 & 51.9 mpg. I am excited for warmer weather as I usually average 5mpg better in the summer.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Hope you don't mind me commenting on your thread but my experience has been exactly as you described (better than I could). I've also been working with @burpod and hope your quest for "daily drivability" is goes smooth. It is hard to keep your right foot out of it for an entire tank;). I will report prior to installing dlc520's and tuning I would average 43-45 mpg during the winter in PA and my last 2 tanks were 50.7 & 51.9 mpg. I am excited for warmer weather as I usually average 5mpg better in the summer.
You running stock wheels and tires?
I'm 38 mpg mixed here
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
You running stock wheels and tires?
I'm 38 mpg mixed here
Krash, I am running 225/45 R17 on some heavy VW Long Beach wheels. With the previous tune and these tires I was seeing 39(ish) with mixed driving. So I would say you are in the same ballpark as I was.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Krash, I am running 225/45 R17 on some heavy VW Long Beach wheels. With the previous tune and these tires I was seeing 39(ish) with mixed driving. So I would say you are in the same ballpark as I was.
Yeah that's what I'm running. I have a roof rack also for bikes (no spoiler).
I'm also tuned with Burpod.

But even after extensive tuning I'm still at this number, which kind of sucks. Obviously wheels and roof rack and winter fuel is a part of it, but still feel like I should be at least mid 40's
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
It is hard to keep your right foot out of it for an entire tank;).
Indeed! Especially when dealing with the traffic here in Los Angeles. I just refilled the tank today and will do so again during my monday commute in order to get a ballpark mileage for this coding. I will then repeat the test twice more, once for the two additional codings, and I will report back what I am seeing. For what it's worth, I only have two options for diesel around here: B20 and R95 (or 99 depending on the source) so my mileage will be different than those of whom use straight #2.
 

yeahkkyle

Well-known member
Joined
Oct 23, 2016
Location
Elysburg, PA
TDI
2003 Jetta 5 speed
You running stock wheels and tires?
I'm 38 mpg mixed here
yes stock wheels. I have a set with Michelin premiers for summer and same set with Nokian hakkapeliitta r3 snow tires, both 195/65r15’s. I attribute some of the drop during winter from the snow tires. Most of my driving is back roads, few stops here and there with 45-50mph avg.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
yeahkkyle

Elysburg, the home of Knobles, I’m about two hours north of you. We make the trip to Knobles once each summer, it’s become a tradition from when my girls were young.
 

hans_gruber0

Member
Joined
Jul 14, 2021
Location
Sierra Foothills
TDI
03' ALH wagon 5 speed
@454k30
Did you have an upgraded SMIC or stock IC plumbing when you upgraded?
Also does the stock EGR fit to the 1752?

Torn between this turbo and the 1749v Stage 1 billet wheel from Xman because I'm just wanting something plug n play
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
@454k30
Did you have an upgraded SMIC or stock IC plumbing when you upgraded?
Also does the stock EGR fit to the 1752?
so this turbo is a direct drop in to replace the VNT-15. Everything bolts up and fits up just like it was the stock turbo.
I have not yet updated my smic. It’s on the list of projects.
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
It's officially been more than a year since my last update. So here we go!

When we left off, Burpod and I were working on dialing in the tune to be both sporty but also efficient as is possible. We did some experimenting with timing as well, but in the end one of his tunes (like the 30th update he sent to me) just felt the most right.

One issue we kept fighting was high IAT and boost creep. The IAT would get so high on long uphill pulls that the car would go into a sort of limp mode designed to protect the components from too high of heat. To clear this I had to cycle the key, thus resetting the ECM, and then start the car again all while doing about 70mph on the LA freeway.

Let me back up a bit though. We had gotten to a tune that I really liked when Burpod suggested we try some tunes with timing that was further retarded. These were not bad tunes, but they just didn't feel as right as the last "advanced" tune he and I had done together. in the meantime, I went ahead and dealt with another problem - the overboost.

I had noticed that my engine had been burning oil for quite sometime, ever since I put a new AMC head on the engine after the stock one was damaged when a lifter failed and took out a cam lobe and lifter bore (what a mess). Over the last summer, the oil consumption spiked to where I was adding a half quart every 400 miles. I have another post that describes this issue in much more detail, but suffice to say it was the valve seals that had failed. The oil that was getting past the valves was coking up the vanes on the VNT. This in turn made the vanes stick and gave me my boost creep. With the valve seals fixed, I disconnected the VNT actuator and worked the vanes back and forth by had until the rough spots in the throw were gone. Then when it was all back together, I took the car out and did a large number of uphill high EGT driving. The amount of smoke produced was astounding! Once the oil and coke had all burned out the boost creep had vanished.

What was best about this was it finally allowed Burpod's tune to shine. The boost control is spot on. The turbo spools well and holds its boost solid. Like it hits 25psi and sits there. In part throttle the boost moves to the commanded level and just sits as it should. There is some fuel smoke under particular driving conditions, but usually it is just a haze at WOT - no coal rolling around. The mileage has also come up. I now see a consistent 41 mpg on D2 and around 39 on B20. I do still need to run a few tanks of the R95 through here and see what the difference is on that.

I also worked the high IAT issue. I purchased an ebay SMIC for about $35usd. Why? Because it was cheap and looked identical to the one for sale by Kerma and a few other name shops. i'd be willing to say that it is identical to the ones sold elsewhere but for 2-3x the price. Anyway, I got that installed, clearanced the bumper, made some rubber isolators, and then connected the stock hoses. Everything went pretty well. IAT is lower now. I am waiting until the summer heat returns to pull some logs to compare to last summer, but I have not been able to get this thing to go into limp since installing the new SMIC.

So that's the update for now. I'll let you all know how the IAT experiment turned out.
 

BlueOnBlack

Well-known member
Joined
Jun 29, 2015
Location
Wi
TDI
15 Passat Tdi Mt6
I also have 17/52 from Xman, paired with .210s at the moment. Only 600 miles in but liking it so far
 

shoebear

Veteran Member
Joined
Aug 1, 2002
Location
Colorado Springs, CO
TDI
1998 Jetta, 2003 Jetta Wagon, 2005 New Beetle, 2013 Sportwagen
With the valve seals fixed...
I also have an oil consumption issue and suspect my valve seals. Is there a write-up or video you found helpful in doing this job? I have never done any head work at all, and I would appreciate a guide.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
I also have an oil consumption issue and suspect my valve seals. Is there a write-up or video you found helpful in doing this job? I have never done any head work at all, and I would appreciate a guide.
I'm in the same boat.
Next TB I was planning on replacing the cam since I found a little bit of pitting last time on cyl 1 lobe. It will only get worse over time. Looks like I'm going to have a LOT larger job on my hands at that point. Mine as well install some 625 studs while I'm at it.
 

shoebear

Veteran Member
Joined
Aug 1, 2002
Location
Colorado Springs, CO
TDI
1998 Jetta, 2003 Jetta Wagon, 2005 New Beetle, 2013 Sportwagen
Looking around, I did find this video which looks helpful.

In this video, he replaces only the #4 cylinder exhaust valve seal. With the engine at TDC, the #4 (and #1) cylinders are at the top of their travel and will prevent the valve from dropping into the cylinders. To do the #2 & 3 cylinders, you could rotate the crank 180*; then rotate another 180* afterwards to return the crank to TDC before you re-install the camshaft.

I am 25K miles from needing a timing belt, and I will probably wait until then to do this.
 
Last edited:

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Looking around, I did find this video which looks helpful.

In this video, he replaces only the #4 cylinder exhaust valve seal. With the engine at TDC, the #4 (and #1) cylinders are at the top of their travel and will prevent the valve from dropping into the cylinders. To do the #2 & 3 cylinders, you could rotate the crank 180*; then rotate another 180* afterwards to return the crank to TDC before you re-install the camshaft.

I am 25K miles from needing a timing belt, and I will probably wait until then to do this.
For some reason I was thinking you had to pull the head
 

454k30

Veteran Member
Joined
Feb 20, 2006
Location
Long Beach, CA
TDI
2002 Jetta
Looking around, I did find this video which looks helpful.

In this video, he replaces only the #4 cylinder exhaust valve seal. With the engine at TDC, the #4 (and #1) cylinders are at the top of their travel and will prevent the valve from dropping into the cylinders. To do the #2 & 3 cylinders, you could rotate the crank 180*; then rotate another 180* afterwards to return the crank to TDC before you re-install the camshaft.

I am 25K miles from needing a timing belt, and I will probably wait until then to do this.
Yeah that's what I did; rotate 180 degrees to hold 2&3.
 

shoebear

Veteran Member
Joined
Aug 1, 2002
Location
Colorado Springs, CO
TDI
1998 Jetta, 2003 Jetta Wagon, 2005 New Beetle, 2013 Sportwagen
I like his homemade tools, but here's a store-bought spring compressor that is made for working with the head on the car. There may be others, but this is the one I found first.
Pelican has their on sale.

Also, a variety of valve seal pliers are available on Amazon for about $10-12 each. They have curved jaws which fit around the seal and allow gripping without damage.
 
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