Anyway, i don't own a turbo car and i know quite a bit about them. I don't know much about the different metals, but i do know this, Inconel in paper sounds as the answer to exhaust problems, now:

At the begining i tought inconel had to had some kind of property not desirable for turbo applications (mind you Formula 1 cars have the exhaust.....hmmm......well, headers, made out of this material). on http://www.burnsstainless.com/ there is an article about the Inconel (http://www.burnsstainless.com/....html) so the thermal properties ARE there, now, i tought that it had to had a thermal expansion greater, or maybe it wasn't as strong, now, looking at the stainless article (http://www.burnsstainless.com/....html) i found a table (at the end of the page) comparing different steels and inconel is there, now, the Tensile Strength is really high, which i didn't tought it would be, also the coeficients of thermal expansion and thermal conductivity are low, which are good because you want in a turbo manifold to NOT disipate heat so the turbo can spool faster.

Now, is there anything i'm missing, or i just found out something that everyone knew?

post your toughts, and mods, if this is out of place i'm sorry.

 

You are ignoring the cost factor... It's a BIG factor on this subject.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99_GS-T &raquo;</TD></TR><TR><TD CLASS="quote">You are ignoring the cost factor... It's a BIG factor on this subject.</TD></TR></TABLE>

that's a fast answer, anyway, yes, you're VERY right, but also, if this metal proves itself that would mean this manifold could hold to a lot more abusse and maybe in the end it would prove cheaper because of longevity, also, if you're crazy enough to use anti lag functions then i guess you have nowhere to go.

But anyway, let's look past the cost, since like everything at some point will become cheaper.

 

It is a very good material for headers, that's why the "top racing" classes like F1 and Top Fuel dragsters(I think) use it.

But when you're talking about a sub $1k manifold to be used on the street it's not a good fit because 1. the cost and 2. the thickness you'd get to use that material and have it fit in your budget(which goes back to 1). Thick wall stainless would then have more strength and work just fine.


So it's not a materials thing, people would use it if they could afford it.

 

yeah inconel is bloody expensive and hard to weld i heard.

stainless is cheaper, and very strong. it suits all the needs of a turbo manifold.

 

Everyone would use Inconel if they could. But the economics don't measure up. There is this principle called the "point of diminished returns", where you start spending a lot more money with very little return. For example, stainless steel costs 50% more than mild steel but it is worth it because of much better properties. Inconel costs a lot more, and is not much better than stainless, so very few people bother.

 

Well if you wanna ignore the ocst factor inconel 625 is wonderufl material for turbo headers. seeing as it doesn't expand quite as much as stainless retains more heat, and is quite a bit stroner you can run a thinner wall thickness therefore saving weight.

I was at one point putting togther a turbo street car and was going to run .035 inco for the header but never finished that one. however i'm putting togther a road race car that will have a .028 wacll thickness header

but as stated comes down to cost cost cost

 

thanks everyone for your answers, this will be usefull for people looking about this material.

To sum things up, inconel is wonderfull, is expensive and not really worth the extra over Stainless because of the price.

It's stronger than stainless, doesn't expand as much, doesn't dissipate heat and it EXPENSIVE.
Thanks

 

It's about 4-5 times more expensive than 321 stainless, correct?

 

on average about 3 times the price of 321 depending on the quantity, thickness, bend radii, and diameter which we can go as large as 3" maybe 4" i have never checked

 

APR uses cast iconel on their vw 1.8t stage 3 kits. I have not heard a single case of failure. The only issues I have ever heard are snapped studs, which is normal. The kit's really expensive, and no parts are available separately.

If you've got the $$, go for it

Evan

 

I think we paid around $40-50/bend for the 321 bends on Rado's header and we were quoted $200/bend for inconel.

 

lmao 200 a bend. i can see me now cutting the first peice, finding out i was off on my cut and then crying.