# Building A Turbo Manifold...Step By Step



## MK1FAN4LIFE (Mar 24, 2007)

Over the next few weeks I'm going to go over all the steps that I follow while building one of my turbo manifolds. I'm always being asked just how I build them, and I've never seen an in-depth write-up on how to make one, so now you're getting one. I will be making this manifold during my break time at work, so progress will be slow, but you will have a complete guide to building a manifold.

Day 1: Prepping the Materials
On the first day I gathered all the materials that I will be using in this manifold and prepared to clean them all. This is a very important step if you want to have a professional quality manifold.

Here is a 90 degree 304SS elbow as I receive them from my supplier. It has ink on the surface along with oils and grease residue from shipping. This will need to be cleaned with acetone to have a good base for the next step.









Here we see the elbow after having been wiped down with acetone. The surface if free of any contaminates, but is not the most appealing, so a mechanical cleaning step will need to be used. This will bring out the luster and beauty of the stainless steel, but will also allow for very nice coloring to be seen after the parts have been welded together.









This is the elbow in its final cleaning phase, and is ready to accept a clean weld. There are many different ways to obtain a finish similar to this on the elbows, but mine remains a trade secret. 









Here we have the stainless steel pipe that we will use to make both the collector and parts of the runners in our manifold. This too is covered in ink and oil so it must be clean.









After cleaning not much of a difference is seen, but DO NOT skip this step. You will kick yourself later if you do.









And here is the part after going through a mechanical cleaning step. This is the one process that really makes the parts shine.









Next we will move onto the flanges in the build. No matter how clean you think the flanges may be, do yourself the favor and clean them again. When I first started making manifolds this was one of the biggest mistakes I made. Assuming that the flanges were clean because they were already shiny.

Here is the head flange followed by the turbo inlet flange.








I just happened to take a picture of a B series flange that I had on me, but I will be building a manifold for a SR20DET.









If you are not gong to use the parts you just cleaned right away make sure you store them in a clean location. Here are a lot of the parts being put away for tomorrow.









Now I just so happened to have a little more time today than expected so I started to cut my collector. There are a million ways to do this, and a million different jigs to use, so I'll leave it up to you to figure this out of your own, but I will give you a tip. When cutting your pipe I’ve found that after the first cut you have to rotate the pipe just beyond 90 degrees. For some reason if you rotate the part exactly 90 degrees the collector doesn't meet up cleanly.
Here is just one of the four parts to my collector.

























And that’s all for today. Tomorrow I will try to finish my collector and will so you how I prep it for welding and the techniques used to do so.

A teaser of two manifolds that I'm working on. At this stage I’m just adding wastegates to the manifolds. The far manifold has an interesting location, it should work out nicely.








And the end result of the process. It may take a little longer to go through all the steps, but it is definitely worth it.


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## vagpower (Aug 25, 2007)

*Re: Building A Turbo Manifold...Step By Step (MK1FAN4LIFE)*

this is awesome.. are you gonna post the pictures of when you add the wastegate... thanks


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## blowndub (Mar 27, 2007)

*Re: Building A Turbo Manifold...Step By Step (vagpower)*

Do you machine the manifold to head flange when it's all said and done? That thing has got to warp all over the place. Isn't sched 10 a bit thin for a turbo mani? Just asking. http://****************.com/smile/emthup.gif What kind of luck have you had with the sched 10? Any probs ever?


_Modified by blowndub at 11:27 AM 5-14-2008_


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## talon223 (Mar 28, 2008)

*Re: Building A Turbo Manifold...Step By Step (blowndub)*

What equipment are you going to be using to weld.


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## Holden McNeil (Jul 26, 2004)

One more request - can u provide at least one method of cutting the collector or your own personal method?


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## Agtronic (May 14, 2001)

*Re: (Holden McNeil)*

No one likes trade secrets!! Reveal all, or don't make a post about it!!








http://****************.com/smile/emthup.gif 
Nice work BTW.


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## bulldogger72 (Mar 16, 2008)

*Re: (Agtronic)*


_Quote, originally posted by *Agtronic* »_No one likes trade secrets!! Reveal all, or don't make a post about it!!








http://****************.com/smile/emthup.gif 
Nice work BTW. 

well, they are certainly not trade secrets
1. prepping the elbow. to make it look like this simply use a SS wire brush (known the trade as a power brush) in a drill press. and run it on a med speed. manually run the elbows around the spiingin wire wheel. we do this to all our elbows here
2. making the collector. there have been several threads here that showed this in the past. basically 3 methods. band saw, abrasive saw, or mill. you need ot make a jig. you need to figure out what angle you want your collector to be. make first cut, rotate, make 2nd cut. ( heres a BIG hint-the 2nd cut is a ghost cut)
oh, and sch10 is fine http://****************.com/smile/emthup.gif


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## Gigitt (May 26, 2004)

*Re: (bulldogger72)*


_Quote, originally posted by *bulldogger72* »_
well, they are certainly not trade secrets
1. prepping the elbow. to make it look like this simply use a SS wire brush (known the trade as a power brush) in a drill press. and run it on a med speed. manually run the elbows around the spiingin wire wheel. we do this to all our elbows here
... 

If you push too hard sideways on a Drill press you start to wear out the bearing and you get end play or wobble.
You can buy a wire wheel for use on a bench grinder... much faster and easier.


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## blowndub (Mar 27, 2007)

*Re: (bulldogger72)*


_Quote, originally posted by *bulldogger72* »_
well, they are certainly not trade secrets
1. prepping the elbow. to make it look like this simply use a SS wire brush (known the trade as a power brush) in a drill press. and run it on a med speed. manually run the elbows around the spiingin wire wheel. we do this to all our elbows here
2. making the collector. there have been several threads here that showed this in the past. basically 3 methods. band saw, abrasive saw, or mill. you need ot make a jig. you need to figure out what angle you want your collector to be. make first cut, rotate, make 2nd cut. ( heres a BIG hint-the 2nd cut is a ghost cut)
oh, and sch10 is fine http://****************.com/smile/emthup.gif 

What about your manifold to head flange and keeping it straight? Do you machine it afterwards?


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (blowndub)*

The "trade secret" was ment to be broken eventually







but a wire wheel and a bench grinder with variable speed is used. This thread is ment to be informative, and I plan to spill all my beans. http://****************.com/smile/emthup.gif 
As far as the head flange. When welding the runners to the flange, the entire peice in bolted into a jig that is able to absorb some of the heat and reduce the warping to the flange. Once it has cooled, it is machined slightly to ensure a perfectly flat surface.
This coming week i'll update the thread with the simple jig I use to cut my collectors, and will also show the steps I take to prep the collector before it sees any welding time. Work has kept me very busy, but I will make updates when I can.
Its nice to see people responding to the thread, it seemed a little slow at first. Hope it helps everybody out there.


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## talon223 (Mar 28, 2008)

*Re: (MK1FAN4LIFE)*

Take your time. Take tons of pictures.


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## weiRtech (Jan 17, 2006)

yeah, i see a lot of important information left out of this writeup. if you are going to do a writeup, don't with-hold information..."trade secrets" are lame... just use a wirewheel on a bench grinder to get that finish... and don't waste time doing it to material you aren't going to be welding, like the material that is cut away on the pipes for the collector. you can save yourself a lot of time by doing the prep just before you weld, rather than the first step. i cut my collectors with absolutely no jig and they turn out just fine.


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## cncpete (Oct 31, 2005)

*Re: (weiRtech)*


_Quote, originally posted by *weiRtech* »_ i cut my collectors with absolutely no jig and they turn out just fine.



What do you mean no jig??? How do you do that?? Tell me you run them through a vertical bandsaw by hand? Pretty sweet if you do!
I cut mine on a cnc mill. I've done them on a manual mill too, but way too much cranking. I use a long 3/4" roughing mill and program it to take off about .100" per pass. All I do is start with a long piece of pipe and clamp it in the vise and program it to cut along an angle (multiple passes like I said, to much to take in one shot). I then made a protractor wheel to slide over the pipe and clamp down on it with a little pointer attached to the table. After both angles are cut (or 3 for 6 cyl.) I will take it out of the vice and cut it off in the band saw. And, YES you do need to rotate past 90°, usually a touch past 92° does the trick for me. It will vary with the height of the collector. That is a trade secret right there, it does not matter how you cut it, it seems you always have to go past 90. I don't hear that talked about much. 








From back in the day, cut this one by hand on the bridgeport.


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## Stroked1.8t (Jan 9, 2004)

*Re: (weiRtech)*



weiRtech[IMG said:


> http://i47.photobucket.com/albums/f161/weirtech/DSC09902.jpg[/IMG]











Can someone hit on how to weld this up? I don't see how you get into those impossible places and lay a bead. I would guess the entire thing is tack assembled and then final welded?


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## bulldogger72 (Mar 16, 2008)

*Re: (Stroked1.8t)*


_Quote, originally posted by *Stroked1.8t* »_
Can someone hit on how to weld this up? I don't see how you get into those impossible places and lay a bead. I would guess the entire thing is tack assembled and then final welded? 

tack everythingup, then break individual runner from collector/head flange, weld, weld to head flange/collector


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (bulldogger72)*


_Quote, originally posted by *bulldogger72* »_
tack everythingup, then break individual runner from collector/head flange, weld, weld to head flange/collector

I follow a much different process, and it has always worked for me. Unlike welding the runners individualy and then to the flange and collector. I'll get to it soon enough. http://****************.com/smile/emthup.gif


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## Stroked1.8t (Jan 9, 2004)

*Re: (MK1FAN4LIFE)*

it looks like you went past it already


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (Stroked1.8t)*

Havn't had time to go over collector making, but I will be doing it tomorrow. In the meantime, heres a little update from the last manifold and a friends car I am building.
ready to cut then weld:








Welded up:








And my friends car. I've built the engine and head, as well as fabbed up the IC piping, turbo manifold, and piecut downpipe. Hope you like.
























And the manifold prior to install (BTW, its an old manifold being modified):


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## weiRtech (Jan 17, 2006)

here is a great alternative to piecuts... i've used them with great success, and i guarantee they won't crack:
http://vibrantperformance.com/...41a7e
if you search around you can find them cheaper. i get mine for less than $30.


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (weiRtech)*

Well I finally pushed through and completed another manifold today, so I was able to document the entire process. I had to take the day off to do so, but I think it was worth it. Today I will show you how I cut and prep the collector for welding, Enjoy!
Here I am going to show you the jig I made for my chop saw. I am going to assume that the most commonly available cutting tool for the amateur fabricator is a chop saw, so I’m demonstrating with it.
Here is the Jig, it is very simple, allows for infinite angles and depths of cut, and seems to work just fine for the application.
































Here is a piece of pipe loaded in the jig. As you can see I’ve marked where the end of the pipe rests so that all four pipes will be the same. Once it has been loaded the first cut can be made.
































The next step will either make or break your collector. You must turn the pipe just slightly past 90 degrees in order to create a collector that merges correctly. I will explain more now.
Here is the pipe turned:








This would be a 90 degree turn as being shown by the perfectly level surface from the previous cut, this is not ideal.








Here you see the ideal angle to cut, just slightly more than 90 degrees. You can see that the bubble in the bullet level is off to the right.








And here is the pipe after making the cut:
















a few more pieces:









Here you can see what you are trying to avoid. While the collector looks very close to being perfect, light can be seen from underneath. If you have this problem it simply means you need to turn your pipe slightly more the next time you cut a collector. This piece is still salvageable; it’s just going to take a little more time to reach a perfect fit.








I’m not too tired yet, so I’ll post how to weld the collector in a little bit.


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## talon223 (Mar 28, 2008)

Wow.
I know this is probably a lot easier than it looks ...but meh
PROPS!


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## sharkytm (Jul 6, 2003)

I just want to say thanks for sharing the information. I understand people protecting their methods, but info like this lets more people learn how to DIY, and thats what this forum is all about. Props to you, man.


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## simon-says (Oct 21, 2007)

*Re: (sharkytm)*

I think this thread is awesome. Because, not everyone has the chance to spend time in a fab shop to watch and learn. Its guys like this, that make the DIY stuff happen in the first place. Sooner or later I'll be making an attempt at a manifold and will be looking back for the TRADE SECRETS.


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## Agtronic (May 14, 2001)

Have you noticed any boost creep with the WG this low on the collector? I've made a manifold almost identical to yours, and the car would boost 15 psi then creep up to 18 by redline. I've found that putting the WG right near the turbine inlet flange helped reduce this.


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## andy9775 (May 29, 2008)

Hey I have a quick question, how do the runners match the ports on the flange is it all flush, or are the runners bigger then the ports then do you weld it and smooth it out?


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## FabricatorX (Aug 3, 2007)

The reason you need to turn the collector piece past 90 is because when cutting on a chop saw, the blade deflects.


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## G60syncro (Feb 7, 2001)

*Re: (FabricatorX)*

No, it's because it's a compound angle... you're rotating the pipe along it's own axis, but you have to take into account the angle of the cut you just made. Basically, the angle between both cuts you made should be a perftect 90* but it's not quite that because you're working on two planes that are'nt parallel to your rotation axis.


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## ftwelder (Feb 27, 2008)

I was wondering where these guys were "losing degrees" . Good call syncro.


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## California Jay (Sep 1, 2004)

*Re: this is a crazy method*

Why would anyone cut two sides of each runner for the collector at a time? You waste time in setup and theres room for more error as shown in this thread.
Make one slice in each runner, 
Pair up runners. 
Weld/tack pairs,
Set up for a new cut on each pair.
Each cut/slice will always match up to the previous cut/slice, no guess work.


_Modified by silly_sohc at 9:11 AM 5-31-2008_


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## weiRtech (Jan 17, 2006)

*Re: this is a crazy method (silly_sohc)*


_Quote, originally posted by *silly_sohc* »_Why would anyone cut two sides of each runner for the collector at a time? You waste time in setup and theres room for more error as shown in this thread.
Make one slice in each runner, 
Pair up runners. 
Weld/tack pairs,
Set up for a new cut on each pair.
Each cut/slice will always match up to the previous cut/slice, no guess work.

_Modified by silly_sohc at 9:11 AM 5-31-2008_

that is how i do it, but i tack two together, then cut the bottom angle that joins to the flange, then cut the joint angle between the other pair. to make 4 collectors, using a stop setup on the saw, i cut the first angle on 16 pieces all at the same time so they are identical. then clean up/polish, deburr and tack, then set the bottom angle and cut the 8 pairs, then adjust for the final cut and cut all 8 pairs again and then tack together.


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## FabricatorX (Aug 3, 2007)

*Re: (G60syncro)*


_Quote, originally posted by *G60syncro* »_No, it's because it's a compound angle... you're rotating the pipe along it's own axis, but you have to take into account the angle of the cut you just made. Basically, the angle between both cuts you made should be a perftect 90* but it's not quite that because you're working on two planes that are'nt parallel to your rotation axis.

You can't say no, it's because it's a compound angle, when in fact, the chop saw blade does deflect, therefore losing degrees. Why is it that when I make the same cut on a bandsaw it comes out right? Because on a 1" bandsaw blade, there is almost no deflection. Each collector piece still needs to be square to fit up to each other piece, therefore calling for 90*.
Just because you are cutting on a third axis doesn't change the orientation of the first two axis. The bandsaw blade for the second cut needs to be perpendicular to the first cut, therefore creating a squared piece. 
Then again, maybe we are talking about two different things...


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## G60syncro (Feb 7, 2001)

*Re: (FabricatorX)*


_Quote, originally posted by *FabricatorX* »_ 
Then again, maybe we are talking about two different things...

Indeed, maybe we do.... Cutting on a bandsaw is different than the setup above. When you're making that second cut, I assume you're resting the workpiece on the surface of the first cut, right?? Then you have a perfect 90* between both cutting planes but the centerline of the pipe is'nt square or parallel to either the table or blade!! That's because you did'nt rotate the pipe along it's true axis. Both methods will give you good results, it's just that the chopsaw one will require a bit more finesse to get proper results.
That being said, I'd also use the bandsaw method because it's much easier and foolproof to get the angles right!!
Proceed with thread, I want to see that thing finished!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 


_Modified by G60syncro at 12:13 PM 6-1-2008_


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## Forty-six and 2 (Jan 21, 2007)

*Re: (G60syncro)*

Great thread. http://****************.com/smile/emthup.gif 
Pretty soon I will be taking a stab at this. Is a tig machine the *only* way to go?


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## andy9775 (May 29, 2008)

*Re: (Forty-six and 2)*


_Quote, originally posted by *forty-six and 2* »_Great thread.
Pretty soon I will be taking a stab at this. Is a tig machine the only way to go?


If you want strength and reliability, yes, although people have used mig. Now would a 17 series torch with a gas lens work or would you need a 9?


_Modified by andy9775 at 6:50 PM 6-5-2008_


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## California Jay (Sep 1, 2004)

iIn planning/thinking out the approach you will take in assembling the manifold, a #9 gun does everything just fine. 
Switching up the nozzle as you go may be your only change when you weld the middle of the collector.


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## 20v_boost (Jan 29, 2002)

*Re: (andy9775)*

Wow, I feel like I kinda over-killed my jig. But for me it was easier to CNC two halves of Plastic to hold the pipe at the right angles. I didn't cut the jig with a band saw, it came off the cnc as pictured. The pictures tell the story.
















































I do have a question. How do you guys get weld the middle of the collector? I couldn't seem to get the torch in there. Don't ask what I did.


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## andy9775 (May 29, 2008)

*Re: (20v_boost)*

The best way to weld in there, assume your talking outside not inside, is to use a gas lens that lets you stick the tungsten out more. Also working in a place with little airflow helps.


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## FabricatorX (Aug 3, 2007)

use that heat resistant tape to block off the back holes, fill the inside with argon, pull the T waaaaaaay waaaaay out there and weld at low low amps.


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## redline6k (Jun 27, 2008)

What angle do you guys cut the collector at. I tried 13* but it didn't come out to great.


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## fastmaxxcooper (Sep 25, 2003)

*Re: (redline6k)*


_Quote, originally posted by *redline6k* »_What angle do you guys cut the collector at. I tried 13* but it didn't come out to great.

i cut mine at 11 degrees and it worked out well


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## nubVR (Apr 25, 2004)

*Re: (fastmaxxcooper)*

wow, this is probably one of the better threads that i have ever read, thanks for everyone that is posting some great information! http://****************.com/smile/emthup.gif


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## michael66899 (Feb 23, 2007)

This thread kicks ass, just wonted to bump it up to keep it going. Thanks for all the info guys, theres a ton of knowledge in here.


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## twicepardoned (May 2, 2006)

Sweet thread... I've been looking at chopping wheels and band saws for some time on craigslist hoping to find a killer deal and start fabbing up stuff.


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## twicepardoned (May 2, 2006)

Where and how are you guys getting head exhaust flanges made?


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## California Jay (Sep 1, 2004)

A lot of fabrication companies or ppl in the biz can give you access to flange sales. They are either water jet/lazer cut or cnc. Some are even advertising in this forum.


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (silly_sohc)*

I will be finishing this thread very soon. I'm taking new pictures with a new camera as the old pictures just werent of very good quality. Just thought everybody should know.


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## twicepardoned (May 2, 2006)

cool


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## NAVI51 (Aug 18, 2008)

*Re: Building A Turbo Manifold...Step By Step (MK1FAN4LIFE)*

does anyone of u know where can I get the flanges for a 93 cabriolet??? the engine is a 1.8 digifant II


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## thetwodubheads (Dec 6, 2004)

*Re: Building A Turbo Manifold...Step By Step (NAVI51)*

I got mine from techtonicstuning.com... All 8v head flanges are the same, old Rabbit motors, newer 2.0s and event the diesels.
Now if we could get some action shots of welding the collector, that'd be great, mkay?


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## V-TEC this!!! (May 4, 2003)

*Re: Building A Turbo Manifold...Step By Step (thetwodubheads)*

this is a great thread. I plan on building myself a manifold but I wanted to know what size piping I should use and where I would be able to find it.


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## NAVI51 (Aug 18, 2008)

*Re: Building A Turbo Manifold...Step By Step (V-TEC this!!!)*

I would recomend u to use 2.5 in piping, I'm not very sure but I think you can get it at Home Depot, it's because here I get it at a specialliced piping place :/


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## xbluewaterx (Jul 20, 2006)

*Re: Building A Turbo Manifold...Step By Step (NAVI51)*

Subscribed!


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## x SPY x (Dec 20, 2007)

*Re: Building A Turbo Manifold...Step By Step (V-TEC this!!!)*

1.5" Stainless sch. 10 is what most people use, unless they are going the thin wall route.

http://****************.com/smile/emthup.gif


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## MA_XXX (Apr 10, 2002)

*Re: Building A Turbo Manifold...Step By Step (x SPY x)*

i've used .065" 304SS with good success. but, you have to support your turbo properly if it's a big bastard. schedule 10 is good for 20V engines. i find they vibrate more and crack thinwall stuff because of the valvetrain.
match the exhaust port size and the size of the tubing you're using. *whatever you do... don't go bigger thinking you're going to get more flow.* for NA engines (headers) you want high velocity to promote scavenging. for FI engines you want to preserve velocity to get that turbine spinning as quickly as possible. more boost generated earlier will outweigh any scavenging effect when you look at how much power is generated.


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## GTijoejoe (Oct 6, 2001)

*Re: Building A Turbo Manifold...Step By Step (MA_XXX)*

I really like this thread


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## XClayX (Apr 30, 2005)

*Re: (silly_sohc)*

WOW, I'm going to have to do that. That's a great Idea for a material holder. Those Two square stock bars and that pipe. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
I always wondered how those collectors were welded so nice.


_Modified by XClayX at 10:31 PM 10-4-2008_


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## evil92gti (Jun 23, 2005)

*Re: (fastmaxxcooper)*


_Quote, originally posted by *fastmaxxcooper* »_
i cut mine at 11 degrees and it worked out well









When you guys do the 13* or 11* cut do you just rotate the sch10 90* and cut to make your collector?


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (evil92gti)*

you have to rotate the pipe roughtly 92 degrees. If you look through my pictures you'll see the level showing that the pipe has been turned past 90 degrees.


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## MK1FAN4LIFE (Mar 24, 2007)

*Re: (MK1FAN4LIFE)*

Well i'm slacking on finishing this thread, but heres a bump and a promise to finish it within the next two months








And heres one of my 1.8t manifolds after 1 hour of driving time. Pulled while removing the trans, byby 3rd gear... and then 1st gear


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## crazyass713 (Dec 28, 2006)

*FV-QR*

Purdy


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