Stainless to mild

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Dean said:
ey your second toe is larger than your large toe. lol

ahahha i dont know if thats a good thing or bad, any one got a foot fetish? lol!! :w00t:

(thats FRONTN's set up btw)
 
Most people make the mistake of putting on a baffled muffler on their turbo'd car's system only to make it flow/sound worse than an un-baffled muffler would.
 
Some old school from a newb. Try some copper somwhere. About 2 feet will do. Works on M.S. and S.S. Pick a straight bit so you dont have to get it bent, cut, swage and away.

Also if you are going stainless, 316 looks flash, but 321 is the grade to use. Use 347 filler rods.
 
tritondan said:
Sorry, nearly forgot to mention, make sure the epa are not with the highway patrol man if he pulls you up. I dont think they like copper exhausts.

That because at temp copper can cause noxious gasses to be emmited?



tritondan said:
Some old school from a newb. Try some copper somwhere. About 2 feet will do. Works on M.S. and S.S. Pick a straight bit so you dont have to get it bent, cut, swage and away.

Also if you are going stainless, 316 looks flash, but 321 is the grade to use. Use 347 filler rods.

I take it you weld a bit then?
Man thatd be expensive wouldnt it? the 321..
Would 304L be good for longevity? considering it has low carbon and wouldnt crack as easily, or would it not take the heat too well?
 
JAP63 said:
That because at temp copper can cause noxious gasses to be emmited?

Umm, yeah, I think. I think its both temp and reaction with gasses. But it sounds cool.



I take it you weld a bit then?
Man thatd be expensive wouldnt it? the 321..
Would 304L be good for longevity? considering it has low carbon and wouldnt crack as easily, or would it not take the heat too well?

Depends on if you want the best.
As for price, you might be surprised. Its got less Mo in it (molybdenum) It will depend on the supplier, and their mark up rates. Shop arround.
Technicly 316 has better creep strength at elevated temps. 316L has max carbon of 0.03% for use where it is not possible to anneal the weld afterwards, making it the better choice. I dont know all this shit, Ive just got a book.

I have made full stainless steel exhausts from eng pipe to tailpipe, with the stainless I could get my hands on, with 316L filler rods, and they work well. Like any exhaust, the trick is to make sure you dont have it "loaded" with pressue, ie, stress. make sure your final connections between joints dosent pull everything.
Dont forget to "purge weld" it.
 
i think 304/310/316/316L was easier to get in larger diam pipes then the other higher grade stuff

but i'm talkin about industrial grade stuff...

317
321
904L
6MoS......

and i think the consumable stuff was....

308L and 347....

thus why i use Mild..... no need to think which grade is really needed.... unless you want the exhaust to outlast the car.... and or human life lol....
 
JayRome said:
i think 304/310/316/316L was easier to get in larger diam pipes then the other higher grade stuff

but i'm talkin about industrial grade stuff...

317
321
904L
6MoS......

and i think the consumable stuff was....

308L and 347....

thus why i use Mild..... no need to think which grade is really needed.... unless you want the exhaust to outlast the car.... and or human life lol....

I agree. Particuly the bit about outlast the car.
Mild has some properties that are hard to go past. Price, availabilty, ease of welding, bending, altering, etc,

I guess the answer to the original post is a simple "yes"
Stainless steel and mild do sound different.

I say design the system for best performance (turbo or non turbo), choose the material you can work with the best, and go for it.
The price for getting all the bending done is going to be the biggie.
 
tritondan said:
Depends on if you want the best.
As for price, you might be surprised. Its got less Mo in it (molybdenum) It will depend on the supplier, and their mark up rates. Shop arround.

Technicly 316 has better creep strength at elevated temps. 316L has max carbon of 0.03% for use where it is not possible to anneal the weld afterwards, making it the better choice. I dont know all this shit, Ive just got a book..

Yeah creep rates are generally for things like blast furnaces and jet engines etc.... and things under pressure and load at high temperatures, creep rate probably isnt a consideration for exhaust, it would be at say the dump pipe area, but further down probably not.
The general idea is how much the thing deforms or moves etc....

tritondan said:
Dont forget to "purge weld" it.

Yeah purge welding is the go, though not many do it..!
 
JAP63 said:
....
Yeah purge welding is the go, though not many do it..!

a tad bit on the pricey side and time consuming.... plus your wasting a huge amount of Argon just to weld not even 30cm of S/S.... and then to make up a jig to block of both ends etc.... i'd just stick to stitch welding with a mig or a good tig welder, if done right it still looks like tig and just as strong.....
 
JayRome said:
a tad bit on the pricey side and time consuming.... plus your wasting a huge amount of Argon just to weld not even 30cm of S/S.... and then to make up a jig to block of both ends etc.... i'd just stick to stitch welding with a mig or a good tig welder, if done right it still looks like tig and just as strong.....

Purge welding aint about the outside.
Its not dear. Jigs?? No!
Heres the trick: Get a tee joint for your argon hose,join on a length of 1/4" hose to it. If you like put a valve in it. An aquairium hose valve will do.
Now get a disc of rubber 1/4" thick or so, cut to fit neatly in one end of the pipe you are welding, put a hole in it so your hose fits. Pack all exits of the headers/ pipes/ etc, with non flamable rag- dont use nylon, its hard to clean if it melts. Use wool or cotton. Dont pack too tight- you want it to breathe a bit. Use silicone rubber if you need to do your welding near it.
All thats left is to set the gas flow on your hand peice and your hose. You want some coming out of both. Then shove your hose into the rubber, remove the best looking rag and allow some gas to purge through the pipe. Stick the rag back in to preserve your gas. It should be able to flow through tha rag slowly.
Contrary to popular belief, you only need gas in there, not a great deal of flow. You can get fussy with reg's but this method gets you flying at home. If you dont belive me, do a test peice with gas and without, then cut them apart. Tell me what you see.

This is mostly intended for TIG, but works very well when using MIG. Works on mild and staino. A stiched MIG weld, purged, can look very nice. It stops unwanted intrusions inside the pipe that you cant check for and cant do anything about.

One other note, if you are doing thin bits, dont forget there is a slight positive pressure (of your choosing) in the pipe. It can muck arround with the final closing weld. :thumbsup:
 
tritondan said:
Purge welding aint about the outside.
Its not dear. Jigs?? No!
Heres the trick: Get a tee joint for your argon hose,join on a length of 1/4" hose to it. If you like put a valve in it. An aquairium hose valve will do.
Now get a disc of rubber 1/4" thick or so, cut to fit neatly in one end of the pipe you are welding, put a hole in it so your hose fits. Pack all exits of the headers/ pipes/ etc, with non flamable rag- dont use nylon, its hard to clean if it melts. Use wool or cotton. Dont pack too tight- you want it to breathe a bit. Use silicone rubber if you need to do your welding near it.
All thats left is to set the gas flow on your hand peice and your hose. You want some coming out of both. Then shove your hose into the rubber, remove the best looking rag and allow some gas to purge through the pipe. Stick the rag back in to preserve your gas. It should be able to flow through tha rag slowly.
Contrary to popular belief, you only need gas in there, not a great deal of flow. You can get fussy with reg's but this method gets you flying at home. If you dont belive me, do a test peice with gas and without, then cut them apart. Tell me what you see.

This is mostly intended for TIG, but works very well when using MIG. Works on mild and staino. A stiched MIG weld, purged, can look very nice. It stops unwanted intrusions inside the pipe that you cant check for and cant do anything about.

One other note, if you are doing thin bits, dont forget there is a slight positive pressure (of your choosing) in the pipe. It can muck arround with the final closing weld. :thumbsup:

ah sall good, i dont think many people get paid enough per exhaust to go all out with purge style welding and prep work (i know i dont lol)
 
JayRome said:
ah sall good, i dont think many people get paid enough per exhaust to go all out with purge style welding and prep work (i know i dont lol)

I hear what your saying. If youre doing on for yourself, or a mate, give it a go. The results are worth it. Only hot rod joints do purging- at a price!!

Happy birthday!
 

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