This year I decided to run a side exit exhaust to save some weight and maybe relieve some back pressure. My previous exhaust was a full 3" aluminum with a vibrant aluminum muffler.

Material: 3.5"OD .035" wall 321 SS (very light!) The entire thing with steel billet flange weighs 3.9lbs. I suspect it will be 4lbs with filler and two o2 bungs.

I pie cut everything since I could not purchase this material in bends without it costing an arm and a leg.



















Started the first round of welding which came out like crap. I am going to focus on consistency when I weld the rest of it. I kinda rushed the fit up which is also a problem. I realized I never really kept the torch angle the same for each pass. I am using .035" ER347 which seems to be working really well! 1/16 was a little too thick for this thin material. I am back purging as well. Machine is an AHP 2015 alpha tig.

Man, I have no idea how you guys cut and weld all that stuff with so much accuracy. I really wish I learned how to weld, but now I'm an old 33 and damn near going to die soon so no sense in starting now.

What did you do with your old aluminum exhaust?

Vegas smith said:

Man, I have no idea how you guys cut and weld all that stuff with so much accuracy. I really wish I learned how to weld, but now I'm an old 33 and damn near going to die soon so no sense in starting now.

What did you do with your old aluminum exhaust?

Click to expand...

sold that shit quickly . went to message him about it the day he posted it when I went to lunch and seen it was already gone

I am surprised you didn't jump on the titanium bandwagon.

Vegas smith said:

Man, I have no idea how you guys cut and weld all that stuff with so much accuracy. I really wish I learned how to weld, but now I'm an old 33 and damn near going to die soon so no sense in starting now.

What did you do with your old aluminum exhaust?

Click to expand...

Accuracy or bust!

I've worked with .03x stainless one time and I'll tell you fitment MUST be tight. Heat control is far more critical and filling gaps is damn near impossible.

Nice work, Scott!

Could of gotten away with 9° cuts to make your life easier.

Either way it looks good!

Vegas smith said:

Man, I have no idea how you guys cut and weld all that stuff with so much accuracy. I really wish I learned how to weld, but now I'm an old 33 and damn near going to die soon so no sense in starting now.

What did you do with your old aluminum exhaust?

Click to expand...

It definitely took some practice to get to this point. I use a table mounted portable band saw to cut the material.

OH91awd said:

sold that sh** quickly . went to message him about it the day he posted it when I went to lunch and seen it was already gone

Click to expand...

OH91awd said:

I am surprised you didn't jump on the titanium bandwagon.

Click to expand...

Haha, it sold insanely quick! I guess thats what happens when no one sells aluminum exhausts for these cars. The entire thing weighed 15lbs with downpipe.

Titanium was over $500 in material, plus they don't offer the borg warner marmon flange in Ti yet. The SS material, flange and o2 bungs came in at $150.

99gst_racer said:

Accuracy or bust!

I've worked with .03x stainless one time and I'll tell you fitment MUST be tight. Heat control is far more critical and filling gaps is damn near impossible.

Nice work, Scott!

Click to expand...

Definitely a pain in the butt with the slightest gap. Thank you!

lasthope05 said:

Could of gotten away with 9° cuts to make your life easier.

Either way it looks good!

Click to expand...

I was really upset I couldn't buy pre bent material, so I wanted it took look as smooth as possible

b00stedtalon2 said:

Haha, it sold insanely quick! I guess thats what happens when no one sells aluminum exhausts for these cars. The entire thing weighed 15lbs with downpipe.

Titanium was over $500 in material, plus they don't offer the borg warner marmon flange in Ti yet. The material, flange and o2 bungs came in at $150.

Click to expand...

yea and now nobody makes an aluminum muffler . I contemplated a ti bumper exit but after pricing everything I decided to keep my heavy ss exhaust out the back

Looks good man

I tried doing pie cuts on my table mounted porta band and all it did was piss me off. I ended up using an abrasive chop saw and that was easier especially being able to angle the fence. That looks really good I'll have to do more practice with my bandsaw when I get out there to do my o2 housing.

brian9397gsx said:

I tried doing pie cuts on my table mounted porta band and all it did was piss me off. I ended up using an abrasive chop saw and that was easier especially being able to angle the fence. That looks really good I'll have to do more practice with my bandsaw when I get out there to do my o2 housing.

Click to expand...

The biggest thing is having a good miter gauge for doing these on a table band saw. I use the incra v27 miter gauge with my swag 3.0 portaband table.

A chop saw would definitely be easier... I just don't own one yet.

That was my biggest issue I don't have a miter gauge. My porta band I made the mount and table the table is 3 16 6061 that's 8 inch by 12 inch but I'm seriously considering ditching the aluminum top for a steel one. The cut chips cut and dig into it, it's fine for anything other than stainless

Man do i hate pie cuts....... so much freaking welding and argon.

The hardest part imo is proping the damn pipe..... drives me crazy

amsrn13 said:

Man do i hate pie cuts....... so much freaking welding and argon.

Click to expand...

amsrn13 said:

The hardest part imo is proping the damn pipe..... drives me crazy

Click to expand...

Yeah man. It's good practice at least. I have to refill my tank before I can continue.

Propping it is definitely interesting...

Looks good Scott.

Props to you, looks good.That sure takes alot of patience. Im learning to weld on my own and when ever i weld butt joints on thin tubing I have hard time keeping from blowing out the ends of the tubing. I would destroy that down pipe.

Xska555 said:

Props to you, looks good.That sure takes alot of patience. Im learning to weld on my own and when ever i weld butt joints on thin tubing I have hard time keeping from blowing out the ends of the tubing. I would destroy that down pipe.

Click to expand...

Thank you!

Heat control is the biggest thing. I'm not sure if your welder has a pulse option, but its helped quite a lot on this downpipe.

I also made a HUGE mistake by not adding at least 3-4 tack welds to each connection. I only added two on each side and i'm finding large gaps opening from the heat. Probably not an issue on thicker material, but most certainly an issue with .035" SS.

You guys can buy laser cut pie you know .

I'd love a link for that when I searched last time I could only find titanium

brian9397gsx said:

I'd love a link for that when I searched last time I could only find titanium

Click to expand...

Ticon (who you probably found the titanium ones) started a sister company called stainless bros, thats what I used on my porsche cat delete pipes.

Awesome thanks