DIY exhaust header

[Jeffer]

I'm wondering if here's anybody who made thir SQ exhaust manifold themselves????

I got al the flanges to make one myself, but i'm thinking about what kind of steel/SS to use or what kind not to use! There must be someone out there that knows.

Greet,
Jeffer

[Pisobiker]

Hi Jeffer,

where did you get the flanges?
I'm tring to find some manufacturer over here to have flanges done for me (laser cut machinery required) but did not yet.
About material, I've seen some tubular headers made out of S.S. and others on "mechanical high resistance steel".
I personally am a little sceptical on using Stainles Steel on turbocharged headers, unless it is a special high strenght stell alloy. Many years ago, when I modified my Fiesta XR2i to Turbo, I custom built the header (that was after succesfully building the N2O system ). Combined heat + weight of turbocharger assembly + heat expansion of ducts (different lengts to have them as short as possible) caused 1st version of header, made out of S.S. (don't remember the SS code) to suffer of many cracking related problems.
Second version was made out of "mechanical high resistance steel" and runned fine for about 20k km until I sold the car.
Anyway on another thread someone of us (don't remeber who) linked to a tuner that makes exhaust headers using S.S. 2348. Maight be worth checking out what kind of alloy it is.

Marco

[Jeffer]

Yo Marco,

http://www.80tq.com/tube_header.html

I Quote:

"Manifold Material- in the high temp. environment of the turbo manifold, the utmost temperature resistance is required. Because of this, standard mild steel is completely unacceptable. Even standard 16g 304 stainless will eventually fail in an unacceptable amount of time under heavy turbo use. In the thinner gauge material such as 16 or 18 gauge, 321 is really the only alloy suitable. But, with increased material thickness temp. resistance also increased (as in the stock cast iron manifolds). To reduce cost but still create a strong, durable manifold I used schedule 10 butt-weld 304 stainless hydraulic pipe (also known as WeldEls). These are a pain to work with as they are hard and thick, but they lay up nicely, create smooth bends, weld strongly and create a very nice manifold when it's all done."

The flanges are made at a machine shop through a friend of mine, He makes them on demand!


Greets

[Jeffer]

This is a very interseting link on building your own SS header!

http://www.burnsstainless.com/TechAr...struction.html

[Pisobiker]

thanks Jeffer.

yeah, I recal now I did use SS 304. Maybe not stiff enaugh.
I used SS 304 for my S2 custom made turbo back 3" exhaust system as well.

How much would your friend charge for complete set of 10mm thick head + turbine + WG flange (4-5 mm thick would be good enaugh for the latter one)?

Marco

[Jeffer]

I'll ask him what it would cost to make them from 321 SS.
I get back to you.

[Dutch_RsBlueS2]

This is a real good thread, im also wondering what kind of S.S to use for my custom built exhaust manifold.

I am lucky because of we have a company which does all kinds of things with metal, we also have some computer controlled milling machines to make the flanges. And i can program those things so that is very handy, maybe i can make some more flanges for interessted people?

But what i`m also looking for is if there are any drawings of those flanges, of do i have to demount my own 3b exhaustmanifold and measure it?

[Jeffer]

Hi Dutch_blue

What are you asking for a set of flanges, I've got a spare manifold lying around. I could send it to you for the sizes? Or come over to you.
Let me know

Greets.

[Pisobiker]

Here you go with the main exhaust flange drawing.
Will follow header to turbo, turbo to downpipe, WG flanges as well (later on, when I find some more time).

Ciao

Marco

[Pisobiker]

Here are the others.
Forgot to take the Manifold to WG flange mesurements...
I'll do that tomorrow.

P.S. Drawings are taken from the gaskets, which may be slightly different from real flange in some places but have more regular shapes which will make them easier to machine.

[Tylerb929]

Sorry, but those aren't right if your making a flange out of them. I've drawn the flange in AutoCad based off the stock 3B exhaust manifold and there is a little bit of difference.

[Pisobiker]

Took 'em from the gaskets. As already written in my previous post, gaskets outer dimensions are slightly different compared to the real flange (in some points), but have a more "clean" shape, easyer to reproduce by machining.

Should also be the same for 3B and ABY. Don't see why it should not:
EM, Turbocharger, WG, everything is the same...

Marco

[Pisobiker]

Tyler929,
given I don't have the best precision tool for mesurements (calliper, which still goes in the 10th of a millimeter range of precision) I may also have not used it with enaugh accuracy.
Just to check this out, I'll go home and bring the header back for mesuring directly from it.
But if you have different sizes why you don't just share them with us?

Marco

[Dutch_RsBlueS2]

Originally posted by Jeffer
Hi Dutch_blue

What are you asking for a set of flanges, I've got a spare manifold lying around. I could send it to you for the sizes? Or come over to you.
Let me know

Greets.

That would be great I guess those measures are the same for a rs2 manifold or any 20V flange Maybe we can figure things out if we meet sometime ?


Thnx for the drawings Pesobiker

[Tylerb929]

Nevermind, I just checked them, there pretty much good except the size of the holes because obviously due to heat expansion the manifold is going to have a larger diameter hole so that it doesn't strip the studs. And of course the stock manifold is cast iron so its not too exact.