How Much Should I Be Paying?

[Roy]

When talking SS prices, be sure to be comparing like for like. There is 304 vs 316 (L grades of each) plus all the other grades of 300 stainless, that are often more suitable for exhausts. You then have various standards for tubing. Your 304 is typically welded tube fit for arhitectural hand rails etc (A554 etc). Some use it no problem in exhaust. Other standards are for pressure piping (A369/270 etc) , heat exchanger tube etc and are far more expensive.

Then on top you have wall thickness....so may not be a case of one place cheaper then others...usually just different. Anyone use Carringtons in western Sydney? They used to be cheaper then Midway, Atlas, Austeel, Sandvik, Prochem, Geordi etc etc

Nice work on the dumps...have to be happy with that

[GTR_JOEY]

Yea very happy with it mate, very happy with what i paid for it all as well as i expected it to be alot more for the amount of effort that was put into it

cant remember what grade of Stainless was used, it was the good sh!t though, very smooth internally and the bends were the same diameter as the rest of the pipe..

wasnt 304, 316 possibly? dont know my stainless very well

[Roy]

LOL, there are more important things in this world to know then grades of stainless My industry uses a lot of it so know a little, I am more interested in what lesser grades of stainless people use and get away with. I used 321 but not sure its worth the expense?

[GTR_JOEY]

i dunno man, i just put the good stuff in lol

[The Dan]

As with most of these things, they have different grades for a reason. A higher number doesn't mean it is better for the job.

304 is typically used in exhaust systems due to the fact it is more malleable and the higher grades like 316 and 321 will polish much shinier but are more brittle so are prone to cracking in high heat situations

[The Dan]

And impressive quality job too mate.

[Roy]

Oh man...this is all from memory...so happy to be corrected. 321 is on paper better then 304 at elevated temperatures due to the inclusion of titanium in it and improves its mechanical properties at high temps. You can get high carbon variants of 304, which are termed 304H. Not 304, and certainly not 304L which is a low carbon version as like 316L they have reduced strength at high temperature so not used for structural/pressure applications at elevated temperatures.

We never use 304 in heat exchangers etc. Quite often we use 321 or other high carbon or stabilised austenitic stainless steels. In an exhaust you dont care about the corrosion properties of ss, rather things like the creep strength, thermal expansion and structural stability/embrittlement which is where the 321 is better. Though they are all about the same with regards to withstanding general corrosion at higher temps in only air.

Years ago I was my old employers boffin on stainless and material selection. That was 12 years ago and now moved more into management so have forgotten the ins and out of the metallurgy of how the grain structures change/react to temps etc.

But at the end of the day if people are using 1.2mm thick welded 304 tube in their dumps and lasting then who gives a shit what texts say. The proof is in the pudding. The lads where i used to work all used 321 for their crazy race boat headers and manifolds etc. The downstream exhaust was often 304, but the manifolds 321. I think you will generally find thats common practice in the old school world of header design and racing. Overkill? I dunno

ps...it was either Prochem or Atlas that had pretty good tech data which may be of interest to anyone that cares

[The Dan]

This is exhaust tubing.

You regular stainless tube sales company that supplies to the automotive and/or light engineering or building industry is not going to be that technical on the grade to the point that you are explaining.

321 contains titanium but it would never be found at places like Tubesales or Right Price Exhausts. The difference between 304 and 316 is the inclusion of Moly in the 316. Their strength is much the same and they have similar corrosion resistance but when you subject 316 to hot and cold cycling close to the melting point, eventually the 316 becomes more brittle than than 304.

321 and 304H are not really used for exhausts. There is no point and they cost more.

304 wouldn't be used in heat exchangers because it is less resistance to corrosion than 321 so with steam, heat or presence of minerals and salts, it will withstand better.

Most of the above has nothing really to do with Joey's exhaust, however. The tube will be 304 or 316 (most likely the latter) and the specific details of the composition of the metal aren't going to change much for him between exhaust shops/fabricators

[Mick_o]

Dont exhaust boys purge weld stainless? I purge everything when it comes stainless pipe and tube it welds nicer and there aint no grinding dags inside pipe or tube ever

The material wont change the cost much, I would go stainless, especially if you plan to go e85.

I think $1500 would be the starting price for a good job, there is an easy 2 days doing it all properly, grinding the inside smooth takes time but nets the extra gains. Dont skimp as crunching the fabricator and making him cut corners will cost you power.

Its not just an exhaust shop you're going to is it? A good performance workshop/fabricator is required imo.

[Roy]

Most exhaust shops dont purge weld stainless because they more often then not MIG. Half the time you look inside and there is pterodactyl shit all over the ID. The other half there is nothing as there isnt full penetration with the weld. I suppose its all post turbine so not often viewed as being worth the expense of using the gas and having the extra regulators/hoses/bungs set up.

Elite, If exhaust places are making dumps out of 304 then good to know. It seems to be the guys that are more into the competition car prep/race fabrication that go for the 321. So probably overkill for road cars. Though if a burner and its coil bundle use 321, LOL I know my dump will outlast the rest of the car

[Bsa]

The price of a mild steel mantle bend is around the 12 dollar mark for a stainless one it's around 65 for one bend. I don't see the big huff about stainless exhaust ends up looking like mild steel anyway after dyno time it would be around the 1200 mark because of so much stuffing around

[GTR_JOEY]

righto last few pics

[The Bogan]

Get it on and tuned man

[N1GTR]

Damn that's looking nice. Hax does good work

[GTR_JOEY]

Yea the work he does is great, really happy with it

I'll be onto yavuz and putting the pressure on to get it done

[Mick_o]

Ya set up looks nice Joey hopefully you dont get my spot on the dyno haha had boost leaks with mine last Thursday so gotta go back AGAIN once i fix it

Yea the work he does is great, really happy with it

I'll be onto yavuz and putting the pressure on to get it done

[GTR_JOEY]

Hey mine was booked in on October 20th so don't feel so bad if mine gets done first

[Piggaz]

Looks unreal Joey!

To hell with off the shelf junk