It's for a 1G FWD DSM. I've done a lot of tubing fitment before and built some exhaust manifolds, but they have always been with a MIG setup. I bought a Thermal Arc 185 TSW a couple months back and this is the first real project I've taken on with it. My camera doesn't take the best up close pictures, so I only have 2 pictures showing the welds.

3" downpipe/O2 housing




3" Cat-back It has to go around a gas tank and over the axle, but I managed to cut out about 90 degrees worth of bends by getting a little creative with the path of the tubing.




Any suggestions or constructive criticism would be greatly appreciated.
Thanks

 

Look great! The fitting is perfect.

 

Nice! Good Job!

 

Good job man! I like the looks of it.

Question.. how much was your Mig?

-Jason

 

just an fyi it was tig'd not migged. looks good!

 

Man......damn it.....that's nice but....I don't know if I should say.

How about this...can you take a picture of the car from the passenger side so I can see the exhaust from that angle?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedej1 &raquo;</TD></TR><TR><TD CLASS="quote">just an fyi it was tig'd not migged. looks good! </TD></TR></TABLE>

Yah, I realized that after I hit post and then I fell asleep.

-Jason

 

I've got a question I hope somebody can answer for me. When I fit the tubes together, I can get the tubes to fity perfectly together before the weld. As I weld, I can watch the tubes expand at slightly different rates. This makes the seam uneven, as can be seen in the second and third pictures.

What's the best way to prevent this from happening?

 

Lots of tack welds or slip fitting the joints.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nowtype &raquo;</TD></TR><TR><TD CLASS="quote">Lots of tack welds or slip fitting the joints.</TD></TR></TABLE>


You don't need lots of tack welds. Just 3 or 4 will do it. Also when you weld get into the habit of crisscrossing your welds, ie a quarter here, then opposite side do another quarter, etc, until the pipe is welded all the way around. This prevents the pipe from expanding on one side.


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F20Cteg, I'll give it a shot. I didn't do it that way because it would cause a lot of start and stop points. But my welds aren't that pretty, so I guess it's not that big of a deal.

Also, am I getting the uneven expansion because I'm not controlling the heat correctly? Or is this to be expeted when welding a bend onto a straight tube simply because of the difference in the metal thickness between the inside and outside radius portions of the tube?

 

This is where a pulser control can help out alot. You can put alot less heat into the weld and the surrounding metal using it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99_GS-T &raquo;</TD></TR><TR><TD CLASS="quote">F20Cteg, I'll give it a shot. I didn't do it that way because it would cause a lot of start and stop points. But my welds aren't that pretty, so I guess it's not that big of a deal.
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The idea would be to go over the spot welds. That way they won't show.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99_GS-T &raquo;</TD></TR><TR><TD CLASS="quote">
Also, am I getting the uneven expansion because I'm not controlling the heat correctly? Or is this to be expeted when welding a bend onto a straight tube simply because of the difference in the metal thickness between the inside and outside radius portions of the tube?
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All materials will expand when heat is applied. SS unfortunately expands more than mild steel. Keep the heat down enough but not enough that the metal is not penetrating.

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