Custom Turbo Manifolds

Tacoma_TDI

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Aug 18, 2017
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Nova Scotia, Canada
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2003 Tacoma ALH Swapped, 2014 SportWagen
Hi all.

Over the next few months I will be building an ALH to swap into my 2003 Toyota Tacoma. I'm currently in the process of cleaning up the motor I just bought to prepare it for performance upgrades. Among those upgrades will be a larger turbocharger and custom FMIC to give the engine enough power to move the truck.

One of the things I am frequently seeing on tuning sites is the list of necessary performance parts needed to support a given tune. In the case of say, a Malone stage 4, they list a VNT17 as being needed over the stock VNT15. What I am wondering is: do I need to run that exact turbo or will I run into any issues building my own turbo manifold and sourcing out a different, but similar, turbocharger? Does this same idea apply to the intake manifold (I hate the design of the stock one as it favors the two middle cylinders)? My ideas here are:

a) I love building stuff myself and have a shop fully capable of doing so
b) I'd like to build a manifold with a turbo flange that is more common, thus allowing me to run any turbo with that flange style, and
c) The stock turbo setup on the ALH interferes with the starter on the Toyota R150F transmission I will be running.

I have attached an image from another Toyota build/swap similar to something I'd like to do. I am just not sure whether or not I'd be able to run a tune with a different turbo than is listed. Any insight on this would be much appreciated. Thanks all!!



http://tdi4runner.blogspot.ca/2012/12/custom-exhaust-manifold-is-finished.html
 

Powder Hound

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'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
I cannot speak to the kind of information that you want, but I will say your manifold looks good so far.

I will give this opinion though. It seems that a lot of people trying to manufacture their own exhaust manifolds have problems in the area of welds cracking. I do not know if the problem lies in selection of materials, the kind of fill metal being used, or just oxidation and slag inclusion in the welds, but the extreme heat and stress that are put into an exhaust manifold, and even more in one that is supporting a turbocharger as well as the higher temperatures involved with turbocharging will make a design your own a substantial problem indeed.

Good luck with this!

PH
 

Tacoma_TDI

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Joined
Aug 18, 2017
Location
Nova Scotia, Canada
TDI
2003 Tacoma ALH Swapped, 2014 SportWagen
I cannot speak to the kind of information that you want, but I will say your manifold looks good so far.

I will give this opinion though. It seems that a lot of people trying to manufacture their own exhaust manifolds have problems in the area of welds cracking. I do not know if the problem lies in selection of materials, the kind of fill metal being used, or just oxidation and slag inclusion in the welds, but the extreme heat and stress that are put into an exhaust manifold, and even more in one that is supporting a turbocharger as well as the higher temperatures involved with turbocharging will make a design your own a substantial problem indeed.

Good luck with this!

PH
I wish it was mine! Though I'm sure I can produce similar results :D.

There are two main reasons (I feel) these things crack a lot. First, people don't follow the three C's of welding: clean, clean, clean. If you don't clean your tungsten, filler, and workpiece your welds will not be happy. Secondly, it's the order in which the manifold is welded. You want to weld your stuff in an order that doesn't cause internal stresses. Tack welding is your best friend!!

I have received an email response from Malone, stating they have no issue providing a custom tune for a project such as this. So, should I pursue the custom manifold route, I will update this post so that others searching for info about this will be informed. :)
 

flee

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Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
Have you considered the Passat manifold? See if you can get your hands on one to check for clearance. It's the one Darkside sells for their big turbo packages.
I have one for my 1756.
 

Tacoma_TDI

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Aug 18, 2017
Location
Nova Scotia, Canada
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2003 Tacoma ALH Swapped, 2014 SportWagen
Have you considered the Passat manifold? See if you can get your hands on one to check for clearance. It's the one Darkside sells for their big turbo packages.
I have one for my 1756.
Excuse my VW ignorance.... BUT, is this manifold only on the diesel passats or on gas models too? I've seen way too much weird stuff with VWs (coming from Toyota) so I need to ask :D. Also, is the turbocharger on the passat bigger than that of the MK4 Golf TDI?
 

vtpsd

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Vermont
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03 jsw TDI, audi 90 AHU swap
The turbo on the passat is slightly bigger (i think only a slightly bigger compressor). I have been loosely planning a tacoma swap, and plan to use my ALH engine with malone stage 3 tune and the passat turbo. I assume they are close enough to be considered equivalent.
 

Tacoma_TDI

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2003 Tacoma ALH Swapped, 2014 SportWagen
The turbo on the passat is slightly bigger (i think only a slightly bigger compressor). I have been loosely planning a tacoma swap, and plan to use my ALH engine with malone stage 3 tune and the passat turbo. I assume they are close enough to be considered equivalent.
I was looking into stage 3 but that's a hell of a lot more torque than my clutch can handle, especially the fact that it happens at 1800rpm. I'm currently trying to figure out a way of running a clutch that doesn't need the flywheel drilled out (run an adapter/spacer vs. drilling) which is proving difficult because of the 8 bolt pattern from the 5VZ vs the 6 bolt on the ALH crank.
 

djrhetoric

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MPLS
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The turbo on the passat is slightly bigger (i think only a slightly bigger compressor). I have been loosely planning a tacoma swap, and plan to use my ALH engine with malone stage 3 tune and the passat turbo. I assume they are close enough to be considered equivalent.
BHW turbo was a VNT-17. ALH turbo was a VNT-15. :)
 

vtpsd

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03 jsw TDI, audi 90 AHU swap
BHW turbo was a VNT-17. ALH turbo was a VNT-15. :)
I understand that, but its a small vnt17, which I think is only larger on the compressor side than a vnt15. This has been discussed ad nauseam on this forum.
 

djrhetoric

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I understand that, but its a small vnt17, which I think is only larger on the compressor side than a vnt15. This has been discussed ad nauseam on this forum.
Only trying to help with some simple descriptions instead of getting into GT1749VA/VB/etc talk.

Tacoma: Talk with your tuner of choice and they'll be able to tell you exactly what you need for hardware. I'm sure they could even make you a custom tune with some torque limitation so you don't break things. :)
 

vtpsd

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03 jsw TDI, audi 90 AHU swap
Is my understanding of the BHW turbo correct? It would seem that it is close enough to a vnt15 from an ALH that tuning for the vnt15 could be used for those of us who would want to put one in a tacoma and not need massive power.
 

Tacoma_TDI

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Nova Scotia, Canada
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2003 Tacoma ALH Swapped, 2014 SportWagen
Another thing that is very desirable about the Passat turbocharger though is the fact that it isnt integrated/cast into a manifold (making my own for clearance purposes). I could just cut the VNT15 off and weld a flange to it, but this is one less thing to do so why not!
 

vtpsd

Veteran Member
Joined
Aug 15, 2013
Location
Vermont
TDI
03 jsw TDI, audi 90 AHU swap
Another thing that is very desirable about the Passat turbocharger though is the fact that it isnt integrated/cast into a manifold (making my own for clearance purposes). I could just cut the VNT15 off and weld a flange to it, but this is one less thing to do so why not!
exactly, and I suspect that you could put this in place of your vnt15 and run it with whatever other hardware your ALH currently has for the vnt15 and it should work fine.
 

jptbay

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Aug 9, 2007
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Thunder Bay
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2003 Beetle, 2006 Jetta Wagon
Does this same idea apply to the intake manifold (I hate the design of the stock one as it favors the two middle cylinders)?
PD150 intake manifold flows much better, and has much more even air distribution. Bolts right on. EGR/race pipe bolt pattern different than ALH.

 
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