Wastegate Turbos Instead of VNT

Tacoma_TDI

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2003 Tacoma ALH Swapped, 2014 SportWagen
I'm going to start of by stating I am fully aware the differences between the VNT and wastegate bypass systems, and that while they accomplish the same thing they are vastly different design-wise.

With that out of the way, I'm wondering how many of you have run a "wastegate style" turbocharger on your diesels. I'm running an ALH in my swapped Tacoma and I'm experiencing really high EGTs, so would like to explore the idea of a larger turbo. There is a tremendous availability of aftermarket wastegate-style turbos on the market, many of which I can get at a discounted rate through local performance shops. I feel like this topic isn't often discussed due to the amount of custom fabrication that would be involved, however I'm running a fully custom log-style manifold in my application so I'm not limited to what I can and can't run. My concern being the ability to tune the ECU to work with a wastegate-style turbo. I would love to hear others' experiences, if any. Thanks all!
 

vtpsd

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It surely can be made to work with a tune. What size turbo are you running? Maybe you just need a larger VNT turbo. I have run a "large" wastegate turbo on my TDI (holset he211), it certainly doesn't guarantee low EGT's. Fueling is also very important in that aspect.

The VNT technology is great, and I will not be using another wastegate turbo in place of a VNT on my next swap (which is also a tacoma).
 

crazyrunner33

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Out of curiosity, what's your idea of really high EGT? On the older VNT I wouldn't worry about the EGT unless if you're sustatining over 1600 for a long period of time, or see your water temp start to rise with high EGT. When the water temp starts to rise, that's when you know you're going too far.
 

Tacoma_TDI

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It surely can be made to work with a tune. What size turbo are you running? Maybe you just need a larger VNT turbo. I have run a "large" wastegate turbo on my TDI (holset he211), it certainly doesn't guarantee low EGT's. Fueling is also very important in that aspect.

The VNT technology is great, and I will not be using another wastegate turbo in place of a VNT on my next swap (which is also a tacoma).

Im running a 1749VA off of a Passat. Why do you say this? You'll love the TDI Tacoma. It's an absolute riot to drive and gets endless questions, wherever I go.

Out of curiosity, what's your idea of really high EGT? On the older VNT I wouldn't worry about the EGT unless if you're sustatining over 1600 for a long period of time, or see your water temp start to rise with high EGT. When the water temp starts to rise, that's when you know you're going too far.

I see 1400-1500 before I back off going up highway hills. It's not that I consider 1400 high, its that holding it up long hills is seems like a bad idea. I've been told that you don't to hold that for too long, where 1600 is a no no. My water temps have stayed absurdly constant, no matter how I drive. Max range when warm is between 78C-86C, according to my OBD reader.
 
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[486]

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auto or manual?
quick spool necessary?
if it needs to light quick, grab a used td04hl-15t-5cm off a HPT 2.3 saab, or any of the he2xx series holsets brand new, but if it can be a bit lazier then go bigger, big turbos are always gentler to the motor when it's getting run hard as it is in a pickup swap

ETA: if you simply disable trouble codes for underboost and overboost you will not run into troubles with a WG turbo on VNT maps, it's how mine's currently set up.
n75 is still plugged in, but just dangling from the wires and not hooked to vacuum or anything, haven't gotten around to figuring out how to disable n75 DTCs yet
 
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KERMA

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wastegate is just the original variable geometry turbo technology
 

crazyrunner33

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Im running a 1749VA off of a Passat. Why do you say this? You'll love the TDI Tacoma. It's an absolute riot to drive and gets endless questions, wherever I go.




I see 1400-1500 before I back off going up highway hills. It's not that I consider 1400 high, its that holding it up long hills is seems like a bad idea. I've been told that you don't to hold that for too long, where 1600 is a no no. My water temps have stayed absurdly constant, no matter how I drive. Max range when warm is between 78C-86C, according to my OBD reader.
Being cautious never hurts. But you're well into the safe area. The limit is the turbine in terms of exhaust temperature. The generation of inconels can hold around 1600 continuously as in all day long, I've tried destroying them at 1800 for 10 minutes and didn't notice any issue with brief moments above 2000 degrees. Should you do that? No, but going above 1600 up a grade shouldn't give you anxiety. I'd be more concerned about the boost gauge and the coolant gauge.

If you do upgrade turbos, I recommend a slightly larger and modern version of the VNT. The newer materials are designed to be able to withstand the abuse from a DPF.
 

Tacoma_TDI

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Being cautious never hurts. But you're well into the safe area. The limit is the turbine in terms of exhaust temperature. The generation of inconels can hold around 1600 continuously as in all day long, I've tried destroying them at 1800 for 10 minutes and didn't notice any issue with brief moments above 2000 degrees. Should you do that? No, but going above 1600 up a grade shouldn't give you anxiety. I'd be more concerned about the boost gauge and the coolant gauge.
If you do upgrade turbos, I recommend a slightly larger and modern version of the VNT. The newer materials are designed to be able to withstand the abuse from a DPF.
I've never seen anyone quote these numbers. I really hope this is the case, but I'm skeptical because people seem to cling to that 1600F religiously. That said, none of them have ever said they've firsthand experienced failure as a result of elevated temps. What turbo did you do this on?
 

Tacoma_TDI

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Joined
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Location
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TDI
2003 Tacoma ALH Swapped, 2014 SportWagen
auto or manual?
quick spool necessary?
if it needs to light quick, grab a used td04hl-15t-5cm off a HPT 2.3 saab, or any of the he2xx series holsets brand new, but if it can be a bit lazier then go bigger, big turbos are always gentler to the motor when it's getting run hard as it is in a pickup swap

ETA: if you simply disable trouble codes for underboost and overboost you will not run into troubles with a WG turbo on VNT maps, it's how mine's currently set up.
n75 is still plugged in, but just dangling from the wires and not hooked to vacuum or anything, haven't gotten around to figuring out how to disable n75 DTCs yet
I have yet to get into modifying the computer myself but I do have an eBay MPPS cable that I hope to use soon. How do you suppress these codes? I have a couple other codes I need to suppress (glow plug, ABS).
 

[486]

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I have yet to get into modifying the computer myself but I do have an eBay MPPS cable that I hope to use soon. How do you suppress these codes? I have a couple other codes I need to suppress (glow plug, ABS).
check the glowplugs link in my signature for the GPs, other codes are similar, you find another trouble code with a similar configuration of data blocks that is disabled and compare it to the code you wish to disable.

you can use either winols (which is kind of tough to get even through non-legal means) or just any hexadecimal editor and then vagedcsuite to redo the checksum
winols does make it a poopload easier to see the patterns what with all its little options
 

crazyrunner33

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I've never seen anyone quote these numbers. I really hope this is the case, but I'm skeptical because people seem to cling to that 1600F religiously. That said, none of them have ever said they've firsthand experienced failure as a result of elevated temps. What turbo did you do this on?
As [486] pointed out, the vanes may deform first on the older VNT, though a lot of turbine failures we've seen like this have been caused by timing issues. Drivbiwire has also been quoted saying the VNT of the generation of the ALH were rated at 900c for max sustain temperature. I've only abused wastegated and non-gated turbos of that generation, only newer VNT and VGT Borgwarner and Garrett turbos I've abused are the newer generation turbos designed to take abuse from a DPF, and they're rated that high.

As far as the craziest abuse I've seen on non-gated Borgwarner turbos of the last 10 years, I've seen them survive brief peaks beyond 3,000 degrees f. One of the fire pumps at a GP paper mill came from the factory with a murphy monitoring system that doesn't shut the engine down until 2,500 EGT, and still retains a 10 year warranty.

If you're worried about the EGT, I wouldn't jump to a massive slow spooling turbo. I'd go for a modern Garrett or BW VNT turbo, they've been designed to withstand some incredible abuse. Also, make sure you're downshifting if there's room to downshift, that lowers the EGT and cools down the engine quite a bit.
 

IndigoBlueWagon

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AHU and 1Z TDIs have wastegate turbos. Lots of people have used the Garrett 20/52 turbo as an upgrade for those cars, with good results. I've thought that a modern ball-bearing wastegate turbo would be a good upgrade for TDIs. The big issue you have to work around is spool time. Wastegate turbos don't build boost as fast as variable vane turbos. They work on the early TDIs because (a) those cars over-fuel and make good power at low revs without much boost; and (b) the turbo is tiny so it spools pretty fast even for a wastegate turbo. But I think you may find there are some good options if you want to get away from variable vane. Look at gasser K03s, 04s, or upgrades to those turbos somewhere like 034 Motorsport.
 

Digital Corpus

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Ol'Rattler
Variable geometry means one of 3 general things these days. Before going into those, the bypass valve allows the excess exhaust gasses to circumvent the turbine preventing an overspeed scenario. Though this is a "duh" comment, it is a practical distinction in comparison to the current methodologies presently employed. This is method is similar to engarging the AR of the exhaust housing. Similar, but the term is used lightly.

The three competing methodologies I've read up on are out adjustable angle vanes controlling the speed of exhaust gasses, a plate that moves a hollow set of vanes over an pre-existing set of vanes to aid in similar speed control, and then a flavor twin-scroll exhaust housings that allow two different ARs to exist in the same exhaust housing.
 

nitec

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myself and a few other folks run Holset WG units on our TDIs...I wouldn't hesitate to build another TDI with a WG turbo - sure it drives slightly differently than the VNT version but I have yet to find myself regretting doing the switch...

I recently sold my B7 A4 that was swapped with a BEW and a Holset He200wg unit. The new owner loves the way the car drives and that's on stock injectors...
 

Ol'Rattler

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Ol'Rattler
Variable geometry means one of 3 general things these days. Before going into those, the bypass valve allows the excess exhaust gasses to circumvent the turbine preventing an overspeed scenario. Though this is a "duh" comment, it is a practical distinction in comparison to the current methodologies presently employed. This is method is similar to engarging the AR of the exhaust housing. Similar, but the term is used lightly.
The three competing methodologies I've read up on are out adjustable angle vanes controlling the speed of exhaust gasses, a plate that moves a hollow set of vanes over an pre-existing set of vanes to aid in similar speed control, and then a flavor twin-scroll exhaust housings that allow two different ARs to exist in the same exhaust housing.
I understand that pretty much. I was asking specifically about this statement:
wastegate is just the original variable geometry turbo technology
I think I understand it better now. https://en.wikipedia.org/wiki/Wastegate Kerma is saying that a VNT and a waste gate do pretty much the same thing. Just in different ways. What's an AR?

And a waste gate is not to be confused with a BOV which dumps or diverts charge air.
 
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Digital Corpus

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I understand that pretty much. I was asking specifically about this statement:

I think I understand it better now. https://en.wikipedia.org/wiki/Wastegate Kerma is saying that a VNT and a waste gate do pretty much the same thing. Just in different ways. What's an AR?

And a waste gate is not to be confused with a BOV which dumps or diverts charge air.
Here on the forums "variable geometry turbo" is used interchangeably with "variable nozzle turbo" even though the latter is a subset of the former. "AR" is more properly written as "A/R," sorry, and is better described here. VNTs help speed up low volume flow and WGs help prevent overspeed from high volume flow. Similar, but opposite ends of the spectrum.
 

Ol'Rattler

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So would it be correct to say that a variable inlet turbo changes the effective Area Radius of the turbo by changing the angle at which airflow enters the turbine? Or is that a concept not related to A/R?

I'm assuming the the actual A/R of the turbine is a fixed value and is not actually adjustable. Would that be true on a VNT turbo? Really appreciate your input on this stuff.
 

Digital Corpus

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So would it be correct to say that a variable inlet turbo changes the effective Area Radius of the turbo by changing the angle at which airflow enters the turbine? Or is that a concept not related to A/R?
I'm assuming the the actual A/R of the turbine is a fixed value and is not actually adjustable. Would that be true on a VNT turbo? Really appreciate your input on this stuff.
Generally A/R is fixed, but can be variable.

This is a good article that is fairly thorough on the types of variable geometry turbos and how each differ. The 10th page shows how a variable A/R can be implemented. Anything in depth I'd say is regurgitation from similar sources.
 

Ol'Rattler

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Generally A/R is fixed, but can be variable.
This is a good article that is fairly thorough on the types of variable geometry turbos and how each differ. The 10th page shows how a variable A/R can be implemented. Anything in depth I'd say is regurgitation from similar sources.
Thanks. I'll read it until my head explodes and then take a break for awhile. :D
 

ketchupshirt88

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since op hasnt posted in a few weeks i dont feel super bad about thread-jacking... But it is related to using a WG turbo on a platform that had a VNT and how to get it all working, etc etc

im looking for a bit of input from guys who have done it already... some of whom have commented here already.

i just strapped an HE221W on my jetta this week, mechanically it is all bolted on and such. Functional but a bit janky, i will be addressing things as time allows - such as better fitting pipework, brackets and CCV port for turbo inlet, upgraded exhaust, etc etc.

A quick nozzle swap next week an then i start tuning it myself. ill break down and pay someone if i epicly fail... It is my daily driver for my 3 day a a week commute but i have a gas guzzling old pickup for a backup. should i start my tuning with the stock ALH file or use a downloaded AGR file from ECUconnections?

I'd like to follow 486's path here and use a manual boost controller set for 26ish and just delete the DTCs for under and overboost... as well as N75, N18 and whatever the ASV solenoid # is - all short to ground because they are no longer present.

is this the correct process for deleting these codes on the ECU in my 2003 jetta? Im not very familiar with winols, i used edcsuite to do my current stage 1-ish tune. https://www.youtube.com/watch?v=xfKWekMHNu8

i copied this for the MBC... think it will work out ok or should i buy a ready made unit? http://speedracer90.tripod.com/mbc/

sorry for the novel, any input is appreciated (other than "just use a VNT like a normal person...")
 

[486]

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I just came from zero on the stock ALH file, gone through about 150 iterations over the 4-5 years.
make sure and get back to us if you figure out the n75 and asv codes, I've just got mine dangling from the wires to keep the limp mode away

took the time to find the n18 EGR one on ecuconnections a long time ago, but haven't bothered with the other two yet
 
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