turbo manifold project (1 Viewer)

[landtank]

now that the old cast manifold has moved on I'm prepared to share my work on a turbo manifold that I've designed.

As others I have borrowed heavily from Dusty's work with weld ells. The design basically posituions the turbo under the manifold and just aft of center. This position allows for a slip joint in the center and should provide ample room up top for plumbing duct work.

Attached here are the drawing files of the tubing configuration and the flange.

 

[landtank]

I've cut a corrugated sample of the flange that I'll fit to the engine to make sure everything lines up prior to actually having a iron one laser cut out.

You'll notice that the exhaust gasket fit quite well and there is a provision for the EGR passage

 

[landtank]

more

 

[vkfzj80]

Good work Rick, It looks like you're well underway to build the manifold,

Have you picked other components to complete the build?

 

[landtank]

I'm still sorting some of that out. I'm getting together with Cattledog tomorrow to further investigate fuel delivery with the stock ECM.

I've got a few irons in the fire right now that need a little more attention before I pull the trigger on having the manifold built and a turbo bought.

But it's getting close.

 

[Dusty]

I think the slip joint issue should be considered. I don't think you will need a slip joint and what a pain that will be. just cut the manifold flange between each exhaust port and make the exhaust manifold flange bolt holes a little larger toward the outermost ports (1,2,5,6). these are the suggestions made by Corky Bell in his book with regards to I6 engines. if that slip joint leaks only a very little bit you will smell smoke in the cab and wont be happy. just yesterday a changed out a blown wastegate gasket that was lightly smoking. But at leaste you can change out wastegate gaskets fairly easily

I only cut the flange between 3 and 4 but I did make larger bolt holes towards the ends. My manifold has more room for thermal expansion because it has a pair of secodary runners.

When I built mine I didn't want the turbo any lower than possible to minimize contact with water f I ever cross any.....but then I mounted my air filter lower than the turbo...so go ahead

and I would leave the flange a half inch thick and dont cut it down to fit the exhaust gasket-leave it beefy as possible to make cracks less likely. after you weld it up it will be a bit warped and will need to be machined flat which may loose up to 1/8 and inch in thickness (mine did) in some places.

 

[landtank]

Dusty, what do you think about chopping it into thirds. That way I can move the T3 flange center stage and have some meat to hang the turbo from. That would make 1+2, 3+4 and 5+6 as pairs.

I'm a little concerned about cutting them up into 6 pieces with that turbo flange bridging two of them.

 

[landtank]

I've been PM'd about updates and finally have something to add to this thread.

About the only thing left from the original design is the drawings themselves.

Using 90* elbows to sweep into the main runner was cost prohibitive and the slip joint fell into the same category as well as getting predictable results was questionable.

So I basically borrowed all the good ideas that I liked from other designs and am using them for my manifold.

Attached is the over view of the manifold as it sits now. The elbows and "Ts" have been cut down to fit properly and chamfered for welding. As some will notice this is how another manifold was built recently.

 

[landtank]

The next series show how expansion will be handled. The manifold will eventually be cut up into three sections. The center section bolt holes are round while the outer sections are elongated. Hopefully I've done my math correctly when calculating the expansion differences at operating temps

 

[landtank]

The next two pictures shows the chamfered joints prior to welding and the inner runner that will need to be welded and then ground smooth.

 

[MSGGrunt]

Looks nice Rick. Did you go with stainless? I'm looking forward to seeing the flange fabricated.

 

[landtank]

The next step is to mount the manifold to the head and position the T4 flange and Tial waste gate flange.

Both of these flanges will be sleeved into the main runner. My hope is to hang the turbo underneath the manifold like the AVO and Safari does at a level that will allow the down pipe to pass under the AC line and still go over the frame in the same way that the stock exhaust does.

The turbo that I've purchased is the GT35R with a 3" V-Band flange so it should have enough room to do what I want in there.

 

[landtank]

Looks nice Rick. Did you go with stainless? I'm looking forward to seeing the flange fabricated.

Everything is 304.

 

[Dusty]

precision. fine work
you probably already know the following:

be sure not to make any of your 3 cuts in the flange till all welding is complete as the flange will expand if you do.

have the flange surfaced after the cuts are made as it will be holding some tension after welding is completed and will flex a bit after you cut the flange. if you surfaced before the cuts are made the flange will not be flat

 

[landtank]

precision. fine work
you probably already know the following:

be sure not to make any of your 3 cuts in the flange till all welding is complete as the flange will expand if you do.

have the flange surfaced after the cuts are made as it will be holding some tension after welding is completed and will flex a bit after you cut the flange. if you surfaced before the cuts are made the flange will not be flat

We talked about this. While I drew up the plans it's two other professionals doing the work. The manifold as it currently sits will be clamped to a 1" piece of steel during welding. Once the entire piece is welded it will be heated to 1500* to stress relieve it and then the two cuts in the exhaust flange will be made. The EGR passage will then be milled and then all three flanges, exhaust, turbo and waste gate will be resurfaced.

I feel fortunate to have these guys working with me on this project.

 

[ls2gto]

Looks great, and really professional. Gaps look perfect for welding. Much easier than trying to fit the 90* elbows. A little loss in potential performance isn't a big deal on a vehicle like we have.

Might be worth it to stress relieve the manifold after welding and before milling the flange. It might warp after a few heat cycles due to some internal stresses. Maybe not, but might be worth it if you hate exhaust leaks as much as I do.

I don't know, maybe I've just had some crappy headers in the past...

Any plans to sell these manifolds?

 

[landtank]

Looks great, and really professional. Gaps look perfect for welding. Much easier than trying to fit the 90* elbows. A little loss in potential performance isn't a big deal on a vehicle like we have.

Might be worth it to stress relieve the manifold after welding and before milling the flange. It might warp after a few heat cycles due to some internal stresses. Maybe not, but might be worth it if you hate exhaust leaks as much as I do.

I don't know, maybe I've just had some crappy headers in the past...

Any plans to sell these manifolds?

Again, this isn't me doing the work, these guys know exactly what they are doing. All the joints look just like the one I posted. The reason for the sleeves is that they needed to be able to cut into the runner and weld it properly. They didn't want to just layer a bunch of passes over itself to fill in the void.

Attached are some pictures of the parts for the T4 flange. These are just rough parts and they need to be machined for final fit. The end result will be that the rectangle tube will be welded together and then slide into the flange itself.

So the tubing gets cut for the flange port. The sleeve is assembled and machined to fit the hole and welded in. Then the T4 flange is slid over the sleeve and welded into place. The same will be done for the wastegate however the sleeve is just a simple turning on a lathe.

I'll be happy to have more made up if people want them but honestly this isn't going to be a cheap part. But I'm hoping it's a good one.

 

[clownmidget]

Rick, that looks beautiful. Don't know if you've made your final decision on where the turbo will sit, but my recommendation is to consider the rest of the "stuff" you want under the hood. For me, I wanted to know that regardless of future mods, the second battery tray, the windshield washer bottle and the grotesquely large cyclonic air filter assembly would fit. And as Dusty has mentioned, the turbo will get so hot it'll glow red after a good run. I know he's counting on his hood liner but keeping it below the manifold is my vote.

 

[landtank]

That stuff has been on my mind for quite some time. Needless to say this build is going in a very different direction from previous ones.

I really have no need for a second battery so that space will be occupied, but my York OBA system should still fit with the stock filter canister in place.

If I get the factory manifolds off and mount this unit for placement I'll shoot some more pics and post them up.

 

[clownmidget]

Rick, another thread reminded me to remind you of the factory bracket that supports the y-pipe - the one that has two bolts into the tranny housing. That is a great mounting point for your own bracket to tie in your down pipe housing and really takes a lot of stress off the manifold studs. Another reason to keep it low