BT Build. Exhaust Manifold and Turbo Fitment Problem

[Steve Chicago]

This is a 99 B5 Passat AEB getting a GT2871R. This turbo is brand new and the manifold I picked up a long time ago in the Classifieds. It appears to be a ATP clone as there are no markings on it anywhere.







This is the fitment problem. The compressor housing interferes with the manifold and the two flanges don't mate.





It doesn't look like I can re-clock this turbo. The internal waste gate mechanism requires the turbine and compressor housings to stay in this alignment with each other.

Any ideas?

Also, I'm not happy with the exhaust manifold outlet size/shape. The gasket matches the turbo inlet perfectly. The manifold outlet does not.





I'm afraid that may cause a flow/reversion problem.

Thoughts?

[SGS]

I cannot see the pictures (stupid goverment computers) but I have done some research on here and I have seen people shave the exhaust manifold to make the ports match. You could do this and probably get it pretty close to the turbo if you have a dremel or something of the sort. Thats where I would start..

[Steve Chicago]

Thanks for the response. It's unfortunate you can't see the pictures. The manifold opening is the larger of the two.

Looking at this again, it appears the crush-ring of the gasket won't be sandwiched all the way around. I imagine that will cause leaks.

[Seerlah]

Restriction is the least of your concerns. You need to worry more about the heat taking pieces of the hanging gasket off and damaging your turbine wheel on it's way out the exhaust. May not happen, but is def a possibility. I would cut my loss and not even run that manifold. Seriously. Is that a Garrett? What sized flanged manifold? Looks deceiving like it wants to be a T25 and T3. Bolt hole size should tell you which it is. But you normally don't see T25 manifold with EWG flanges (they exist, but not are very common). I never really dealt with the IWG setups, but you should be able to run a different bracket to reclock the turbo. Use a bracket that uses the clamping bolts for the compressor housing.

http://www.atpturbo.com/mm5/merchant...Category_Code=

Also, you can post in the B5 A4 section. We don't show disdain towards other members, let alone Passat owners. There is even one on there with a 60 trim. You will get more help if you make a thread in there.

[Steve Chicago]

Thanks for the reply.

Good point about the unprotected gasket areas being blasted away and potentially causing foreign object damage to the turbine.

Yes, the turbo is a Garrett I just received from 034 Motorsport.



The manifold outlet bolt holes match up perfectly with the T25 gasket but as you can see in the pencil tracings above, the exhaust port does not.

This waste gate actuator is permanently attached to the bracket. The bracket only fits in one place.





I'd need to buy a new actuator to use one of the ATP brackets.

This manifold looks exactly like these on ATP and 034 websites. Even the shape of the exhaust port looks the same.

http://www.atpturbo.com/mm5/merchant...gory_Code=VVWM


http://www.034motorsport.com/engine-...3-p-18951.html


So is this a T3 ported manifold that has flange holes drilled for a T25 flange?

I think the solution is to get a turbo and manifold that are designed to fit with each other. Silly me assumed a T25 manifold and a T25 turbo would fit together. What was I smoking!

Would it be a smart idea to ask that this thread moved to the other forum? The more experienced feedback I can get, the better.

[Seerlah]

You can do that. Send a PM to Anthony (Admin) and request this moved to the B5 A4 section. But the easy way to tell if it is a T25 or T3 manifold is the thread bolt holes. If it is m8x1.25, then it is a T25 manifold. If it is m10x1.5 then it is a T3 manifold. Also looked up the specs on the ATP manifold, and it uses the same design for both T3 and T25. Difference is the bolt holes. People have ran the ATP clone with no issues, other than installing and uninstalling. So you may just want to pick up a different IWG setup. Or maybe talk to 034 and see if they can help you out.

Actually, going by the pic you should have enough room to rotate the compressor housing to have the outlet clear the manifold. And you need to reclock the CHRA to have the oil drain pointed downwards.

[Steve Chicago]

The threaded bolt holes in the manifold flange are M8x1.25

Next is to see what options I have from 034.

[Crispy222]

You could buy a steel T25 flange from fleabay and have it welded to your manifold. That would give you the clearance and take care of the outlet shape so it matches your gasket and turbo flange better. You want to have it milled or atleast decked with a industrial belt sander after welding. Probably have <$40 into the 'fix'.

It looks like someone in China copied the T3 manifold with T25 bolt holes and pattern.

[Steve Chicago]

You could buy a steel T25 flange from fleabay and have it welded to your manifold.

That's a great idea. And probably the most practical.

I'm now thinking of going with this manifold... http://www.atpturbo.com/mm5/merchant...gory_Code=VVWM


And a Tial vband turbine housing... http://www.atpturbo.com/mm5/merchant...egory_Code=TTH


And running external an waste gate.

[Crispy222]

So now you're looking at another $1200 to get a GT2871 connected and you still need a downpipe and lines? Personally the tial housing is so over kill for what you going to do. Its mainly designed with the intent you would be pulling the turbo every week after a hard few days of racing, road or rally. If you want to spend more money, do it on a different manifold that will work with the GT2871 the way it is and some rods before you window your block. You can easily spend $1000 inside the motor just on refreshing it.

[Steve Chicago]

It's a new engine with rods from IE just installed. I've already got the water and oil line kit from 034. No down pipe yet.

I'm trying to avoid endless flange leaks and loosening bolts I keep reading about. I figure roughly 1000 for the manifold, housing and vband clamps.

[Crispy222]

I haven't had a problem running studs and copper lock nuts, ever. You're not going to hear about all the people that never have issues with stud/nut combo.

Problem show up when parts are not checked prior to mating (especially used parts), stripping bolts/threads in soft cast manifolds, and many time the wrong/used hardware.

http://www.ebay.com/itm/T25-T28-GT25...f52183&vxp=mtr
http://www.atpturbo.com/mm5/merchant...egory_Code=FST
http://www.atpturbo.com/mm5/merchant...egory_Code=FST

$16+7+shipping+$30 to have someone weld it to your manifold and sand/mill it flat. <$60

[Steve Chicago]

I put the manifold in an electrolysis tank for a while and it cleaned up well.

[Steve Chicago]

I don't know who originally designed this manifold, but it's a common casting sold by many different companies.

I researched the dimensions of the T2 and T3 turbo flanges and this casting is neither. It's somewhere in between the two. And the shape of the port is also wrong. This seems to be common to all the various versions of this manifold out there. Google around and every picture you find will have this six sided port and not a four sided rectangle like the turbocharger flange has. It appears they sell this same manifold to both T2 and T3 users and simply drill the mounting holes different depending on which turbo you're running. Will it work? Sure. Is it going to flow optimally for either turbo? No. It's going to have an abrupt transition and create turbulence immediately before the flow hits the turbine. That's right where you want smooth laminar flow pushing on the turbine.

And another thing... the gasket for the T2 flange does not get covered correctly by the odd shaped manifold flange/port.

T2 gasket with crush-ring.


How the gasket lines up to the odd shape port on the manifold. Half of the crush ring isn't going to get crushed and create a good seal.


And to that end...... a flange with a T2 port on one side and transitioning to the bastard port on the manifold. (can I say bastard on here?)

T2 flange with a layer of blue tape on it.


Bolted to the manifold.


From inside the manifold.
This is the abrupt step the exhaust flow hits as it passes from the manifold to the turbo.


Scratching away the blue tape to mark the port dimensions.


Removed from the manifold so the port can be ground/matched.


Dremel, file, cursing, play with dog, Dremel some more...


Starting to look familiar?


The new flow path.








After the two parts get welded together it'll get a final smoothing at the transition.

[Crispy222]

awesome work, making it happen.

[Seerlah]

Great work, there

[Steve Chicago]

The flange is stainless steel. It was listed on ebay as mild steel. No wonder it was so hard to work. I never even thought to give it the "magnet test". Talk about feeling dumb.

[Steve Chicago]

I've got another flange on order from a non-ebay source. With projects like this, the second attempt always turns out better then the first.

[Seerlah]

Wasn't happy with the first attempt? Looked good to me.

[Steve Chicago]

It turns out the flange I got is made of stainless steel, not mild steel as advertised. The flange is going to be welded to the cast manifold. The guy doing the welding said he could weld it but it won't last. So I'm re-making the adapter out of a more suitable metal.

Anyone want a stainless steel T28 flange? It'd be perfect for someone fabricating a stainless tubular manifold.

[audi with bmc]

Like you said, the second attempt always turns out better then the first. BTW Good work!


On another note, do you remember me?

[Steve Chicago]

The name is familiar but I had to search before I remembered. Did you ever figure out the solution to that problem?

[audi with bmc]

It was/is a hot mess! Inbox me your number, I lost my phone awhile back. We need to meet up some day this spring. It's a long story and the end is yet to come. Although my car has been back on the road.