Hey guys, Im looking at getting a 3" prebent exhaust from kteller.com as there prices are very good it seems for a standard prebent exhaust and I can weld it up and make some hangers.

Im currently running open downpipe, which is made of mild steel. Using a fluxcore welder. I am looking to flange my current downpipe and add the exhaust to the rear

Would aluminized or mild steel be better in anyway? Im assuming my fluxcore welder would be fine with the aluminized, but am not sure. I was very amazed with how nice a bead I could get with the .065" wall mild steel.

Id like the exhaust to last atleast a few years, I will probably change setups a few times during that period, but dont see a real need to switch a good 3" exhaust if its in good condition..

 

Aluminized produces toxic gasses when welded, you'd need to grind the coating off. And uncoated mild steel will rust in a very short time period

Save up and get the stainless kit, your investment will last much longer and still have resale value

 

I think you mean aluminized vs stainless steel right?

 

You will have a very hard time welding stainless steel with a flux core welder. Go with the aluminized mild steel. It lasts on average 10-15 years at least depending on where you live.

 

Except at the welds, that will be the weak link since you have to remove the galvanized coating to weld it properly... then you have a mild steel weld and small sections of no coating which will
Be the first place to fail

 

There are typically 3 grades of stainless; 409, 304, and 316. The 409 is what is used on most new cars. It's durable, but will get a light rust color in a year or 2. The 304 is extremely high quality, but costs much more than the 409. The 316 is for those who are quite ****. Polished stainless is either the 304 or 316.

I'd recommend getting 409 stainless. Most exhaust shops either have, or can get 3" 409. That is my default exhaust pipe.

Mike

 

paint that shiznit yo.

im using the aluminized kteller kit on my turbo car. ive had the exhaust since 2006 and it was welded up with my flux core lincoln welder at the time. it has very light surface rust at best and is in pretty good shape overall. i made the downpipe at the same time with aluminized bends from summit and i primed and painted it with ceramic 2000 degree paint. you should clean off the coating and then bevel where you are going to weld it up though.

 

You excluded 321 stainless, the best grade for a lot of of motorsports applications

304 is the most common grade due to low cost and high availability.

 

Because 321 is stabilized with titanium, equivalent to at least 5 times the carbon content

Then there's 321H which has a higher carbon content than standard 321.

Then 347, basically the highest grade one would use in motorsports, it's similar to 304 and 321 except it's stabilized with columbium and tantalum. It has an incredible temperature limit compared to 304 and 321.

An there's also 347H, which like 321H has higher carbon content for higher temperature thresholds.

The grades are vast and each have a purpose from 200 series to the 2000 series

 

Sounds like aluminized is what I want. Cheap and fairly long lasting and easy to weld.

I will definetely bevel the edges and try and move the coating on the joints and respray the exhaust in high temp paint afterwards

I'll take your advice and weld it up outside aswell

 

i thought it was only the cheapo galvanized pipe from parts stores do that. It burns yellowish/green when welded


back in the day when i was flux core master, ive welded 409 & 304 ss with good sucess. obviously the weld was not ss, but it welded just fine.

 

So maybe I should go with his stainless kit for the $50 extra?? Would the welds rust quite quickly even if painted?

 

You'd need high temp paint...

And you can't flux core stainless... you need to mig it, they don't ,take stainless flux core wire

 

you can convert your flux core to gas for cheap and have much better weld, but if not, mild steel.