Done it on multiple vehicles with no issues and I only use regular old flux wire for welding. I also don’t have salt to contend with.
CK5
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Where are all my exhaust fab experts at?
- Thread starter jtrux
- Start date
I like to weld everything on exhaust with stainless wire, even if it's aluminized mild steel. The joints last longer. I don't worry about purging or anything and just use regular C20 shield gas. It's an exhaust pipe, not medical processing equipment. I don't know the metallurgy, just that it seems to work fine.
Aluminized steel is just a coating just clean back where you’re gonna weld the v-bands
I brush and spray all my welds anyway
Depends on my mood sometimes I take my time, use jigs , math multiple fit ups and sometimes I hold it up with one eye closed n send it
I guess I should add, you absolutely can weld mild steel to stainless. You’ll just have to use tri-gas if you decide to use the ol glue gun for speed (mig) and of course you’ll have to find a happy medium as far as heat goes between the two metals
Why tri-gas? Several times I've welded stainless to mild with regular 'ol 75/25 and it seemed to work fine?
Honestly I’ve never tried to weld ss without it so I just switch bottles when I am welding it
Oh. Well I thought I was about to learn something lol. I've migged a heck of a lot of steel together over the years, but I'm basically self-taught and have never considered myself to be a professional of any kind.
I can't speak to how much better tri-gas works for exhaust because I've never had any, but as I said before, regular shield gas works fine. If you're making food-production equipment or high-pressure pipelines, the proper gas and back-purging with nitrogen may be important, but your tailpipe(s) doesn't have the same requirements. A decent exhaust will never be more than like 1psi above ambient. This is especially true where you're able to flare pipes and do overlap welds, as opposed to butt-welds in the pipe. The biggest issues for exhaust are the water in the pipe that is natural for internal combustion and the road salt, for areas that vandalize tax-payers vehicles (YMMV).
People rave about V-bands (i.e. butt-welds, plus clamping parts with gaps), but I've never had ones that didn't leak, which may be why most success stories include putting silicone in them.
If it’s not spec for something, I’ve ran 75-25 on SS wire. Went back 20 years later and it still looks new, even in a corrosive environment
Probably not an issue
I can not TIG 20 gauge or thinner SS without tri gas. Tried 100 argon and 75/25. No luck. The heat seems to walk farther into the material with non tri glasses.
Is there a pre-made exhaust kit that has all the bends fabricated?
luna negra
Newbie
I bought this kit and it worked great. https://www.summitracing.com/parts/WLK-89005
I’ve used the kit from speedway.
That chart is way off for performance. From real world experience you need larger pipes than that for best performance. I would pick up 20 HP from only around 400 HP going from dual 2.5" to dual 3". I've seen this on multiple occasions too. In my app I have the exhaust size calculated, there is also Pipemax available specifically for that.
As far as building it, they sell kits with bends that help a lot, I can get some of them through my distributors. Aluminized or SS. Also, header or manifold back.
With those kits I've built entire systems without a butt weld, just lap joints.
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@folkenheath
What would you recommend for a 5.3 swap with stock manifolds ? Dont want headers now . Was thinking 2.5" from manifolds to a merge y and then single 3" out from there .
What would you recommend for a 5.3 swap with stock manifolds ? Dont want headers now . Was thinking 2.5" from manifolds to a merge y and then single 3" out from there .
When you retain stock manifolds it isn't going to matter as much because it's choked too much right out of the head. With that said, in that case my suggestion would be at least the same diameter as the manifold outlet. So if the manifold outlet is 2.5", then dual 2.5" minimum. To maintain the flow area of a dual 2.5 in a single would require a single 3.5" piece. If its only dual 2.25" you can barely get away with a single 3", you may lose a little power. If you put on a restrictive muffler, you will lose power because the muffler can't maintain the flow of the pipe diameter. Some mufflers flow nearly as much as the open pipe, like Borla for example. It's up to your project to balance power/sound.
Now, flow area does not equal flow, because as the pipe gets larger the area increases exponentially while the circumference (ID friction surface) only increases linearly. That means smaller pipes flows less per area than larger pipes. However, maintaining area is close enough in many applications, also, you aren't going to see extreme differences in pipe size anyway. This is not the case with collectors as the combined flow does not need to equal the cylinder flow because they are firing at different times. So you have a ratio, but unless you are building your own headers you don't need to worry about that, then you get into stepped headers, etc. My app will also calculate recommended header primary and collector diameters.
You can see the flow area in this simple excel chart I made below.
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People rave about V-bands (i.e. butt-welds, plus clamping parts with gaps), but I've never had ones that didn't leak, which may be why most success stories include putting silicone in them.
I just had mine off to replace the hangar rubber on my truck. I've got two vbands right before my X tube and two more at the race bullets. Only one showed a bit of soot where there was a small leak, and this was the X tube. I do use silicone, but I also remember I ran the truck last time about 10 minutes after the silicone was put on and exhaust reinstalled. Lol.
I think a big thing where people have trouble is keeping the heat minimal on the faced parts during welding. Any warpage there is gonna screw you up.
