Build your own exhaust

[91 Turbo Mitsu]

Found a new company on Ebay that sells mandrel bent pipes in 16gauge and stainless. Their prices are very reasonable. I bought a 180 mandrel, a 90 mandrel and 2 sections of 4'pipe all in 3" 16 gauge steel with shipping for under a $100.00.This should be enough for me to build my exhaust from the turbo back. I just got the 2 mandrel bent pieces and they look awesome. Check out their store.http://stores.ebay.com/Mandrel-Bending-Solutions

 

[sonicnofadz]

I'm not a welding expert, or metallurgist, but doesn't mild steel last longer than stainless steel in high heat situations? Why is it that stainless manifolds always crack where cast iron or steel manifolds seem to last forever?

 

[speedy_talon28]

hhhmmm? interesting, I would have swear you used a arc welder by the welds. maybe it's because I can't use a mig welder that well, . good job

 

[GVR4592]

I'm not a welding expert, or metallurgist, but doesn't mild steel last longer than stainless steel in high heat situations? Why is it that stainless manifolds always crack where cast iron or steel manifolds seem to last forever?

That's a good question. Stainless steel has a much higher thermal expansion rate than mild steel. Stainless steel expands at a very high rate and causes a lot of stress. The high heat and the stress really work the weak parts of the manifold and it eventually cracks. The weak points come from a combination of thin walled tubing, crappy welding/prep, bad design, and improper bracing.

Most high quality manifolds are made from 321 cast bends. They are very thick and handle high heat and stresses much better than a thin piece of 304 stainless that is commonly used in the ebay manifolds and others like them.

 

[rst95eclipse]

Steel fails around 2750 degrees Fahrenheit. Stainless steel fails around 1900 degrees (when held over a long duration of time depending on mass). However, both of these numbers can be increased and decreased depending on the grade and rating of the material. I will be fabricating my exhaust manifold and downpipe out of mild steel.

For the comment on the downpipes flow characteristics, it will not be the most efficient 3" downpipe, but it will work. The breaks, and I can imagine the weld continued inside the pipe as well, will create turbulence. A smooth mandrel bend will not create as much.

 

[rst95eclipse]

I would have swear you used a arc welder by the welds. maybe it's because I can't use a mig welder that well

A Mig is much easier to use.

 

[thjones3]

A lot of time went into making that downpipe . I will be making mine from 3" aluminized steel tubing. I use a lincoln MIG welder at home, but I want a Miller TIG. TIG welder FTW .

 

[rst95eclipse]

My experience with aluminized pipe is that it just doesn't work. I used some 2.5" for some IC piping and it rusted within 2 days.

 

[91 Turbo Mitsu]

My experience with aluminized pipe is that it just doesn't work. I used some 2.5" for some IC piping and it rusted within 2 days.

What I do is clean the pipe then use a torch to warm it up then I spray on some hight emp paint. seems to last a long time for me and I live in vermont where they salt the roads all winter long. I will try to post some pics if the finished exhaust and external dump wastegate for everyone to see. Thanks to all for the responses. Travis

 

[sonicnofadz]

A lot of time went into making that downpipe . I will be making mine from 3" aluminized steel tubing. I use a lincoln MIG welder at home, but I want a Miller TIG. TIG welder FTW .

TIG is what you are supposed to use when welding exhaust. I don't think MIG is a very good idea...

 

[xveganxcowboyx]

TIG is what you are supposed to use when welding exhaust. I don't think MIG is a very good idea...

Why not? Exhaust = Metal MIG = welds metal

Worked fine for me anyway. And that was a cheap gassless junker.

 

[91 Turbo Mitsu]

TIG is what you are supposed to use when welding exhaust. I don't think MIG is a very good idea...

I am a mechanic and have personally never seen an exhaust shop that used a tig welder to build exhausts but it works great. Usually a tig is used for stainless( can use a mig but it is harder) and welding things like aluminum.

 

[brandonzero0]

Yes using TIG is nice i have TIg and MIG Tig is the way to go if you know how to use one and have access to one, MiG is easier to use though.

 

[91 Turbo Mitsu]

Here is a couple of pics of my finished exhaust. I had to trim a little of the side skirt so I could tuck it up as far as possible.

 

[rst95eclipse]

As 91_Turbo_Mitsu stated, Mig is just fine to use on exhaust parts. It just so happens that Tig gives a much better outcome when it comes to aluminum and stainless steel.

 

[fulanititoo8198]

Awesome work, now if I only had a welder.

 

[thjones3]

What type of wire are you using in your MIG for stainless? I thought stainless had to be surrounded with a sheilding gas (back-gassed).

 

[91 Turbo Mitsu]

What type of wire are you using in your MIG for stainless? I thought stainless had to be surrounded with a sheilding gas (back-gassed).

I have never personally used a mig for stainless but you can buy stainless wire at for a mig at my local auto parts store. Travis

 

[eldiabloz13]

VT. Good old cabot cheese. Now whats the exhaust for. Coming out by the tires like that it looks like its for a damn mustang. Now where did you get the flux piping to make the DP. How big is that piping. Where did you also get the flange for the turbo outlet.

 

[91 Turbo Mitsu]

VT. Good old cabot cheese. Now whats the exhaust for. Coming out by the tires like that it looks like its for a damn mustang. Now where did you get the flux piping to make the DP. How big is that piping. Where did you also get the flange for the turbo outlet.

The exhaust is on my 91 turbo eclipse.I like the side exit becuase it means a lot less bends. I think I have three bends in the whole exhaust. The downpipe I made from several pie cut pieces to make the curve down around the oil filter. It is 3" piping from the turbo back. The 5 bolt flange I bought from a company on ebay for I think it was $12.00. If you really want to know I can check my history to see the name of the company and the exact price. Travis

 

[eldiabloz13]

Isnt it loud as hell. With no muffler and all. Now i was saying the FLUX mesh that is on the DP. The stuff that bends to cope with street on the exhaust. Where did you get that

 

[xveganxcowboyx]

Isnt it loud as hell. With no muffler and all. Now i was saying the FLUX mesh that is on the DP. The stuff that bends to cope with street on the exhaust. Where did you get that

You mean the FLEX pipe? You can buy them anywhere that sells exhaust components. And, as always, ebay.

 

[eldiabloz13]

Yeh the flex mesh. In my area its called FLUX for some reason like thats the brand of it.

 

[91 Turbo Mitsu]

Yeh the flex mesh. In my area its called FLUX for some reason like thats the brand of it.

E Bay for $18.00 and it is a heavy duty piece. When I got it I was shocked at how thick it was. It is about 3/4 of an inch in the middle. Travis

 

[Dorifto]

Looks very nice! I imagine it sounds ungodly beasty as well, the 40-series has quite the tone to it. Very nice fabrication, much time and effort was put into that.

Any chance we will be graced with sound clips?

 

[BISHILVR]

Hey, you do know that those worm clamps are'nt going to hold on that turbo right? !