Header: Stainless vs. Mild
 

I was looking at the Racing Beat site and they offer 2 versions of their streetable header. One is mild steel and the other is 304 stainless steel. RB notes the weight difference (7 less for the 304), but what are the other differences? I'd rather not shell out an extra $100 (or whatever the difference would be used) if it's not worth it.

P.S. Via my Google search I came across this gem: http://www.yarisworld.com/forums/sho...d.php?p=193173. Hopefully that link won't derail my thread too much.

i know that Starspeed racing is trying to make some SS headers like RB or SJD....look into those as an inexpensive alternative.

Stainless real advantages over mild steel besides being more resistant to corrosion and rust is they dissapate heat better. but i would get the mild steel and ceramic coat them. around the same price in the end, but SS advantages can not compete with the ceramic coating.

Why not then just coat stainless?

My understanding is that ceramic coating will lock out corrosion/rust (think of it as heat/moisture resistant paint) and insulate much better. This will decrease under hood temps and increase exhaust velocity. So basically it just uses the header as a structure to adhere to and could care less (to a viable point) what it's made out of.

You could then pay the extra $100 for stainless to save 7 lbs!

You can loose that 7lbs somewhere else. Go with the higher quality material and if you want to get that ceramic coated inside and out and it is even more gains.

Just don't header wrap it if you plan on driving it in wet conditions because it will rot your pipes very quickly.

Usually you can use a silicon spray of somesort underneath the wrap to lock out water and moisture.

I'm inferring that stainless is a better material than mild steel, or do I have it backwards?

Yes and no. Really depends on your application of what you desire/need. If you want a header that's not going to be wrapped and not going to be used to spool a turbo, then by all means go with the stainless.

If however you're going to be spooling a turbo the less heat that the header absorbs the better (however the cast Iron one's do quite well if not better at spooling a turbo). Your biggest thing you want is to make sure you keep heat in the manifold and not in your engine bay. Stainless steel is known to crack if not welded correctly in/on the manifold, it's also known to crack if you decide to wrap it. It all depends.

Great, thanks for the information.

As a followup, what makes the stainless crack if you decide to wrap it?

what really matters is the quality of the stainless steel. Cheap stuff cracks because generally its not the grade they claim to be using OR the flange and the tubing are different in material which causes a lower quality weld.

I would opt for stainless steel over mild just from what i know regarding materials. Even with a ceramic coating, you'll get rust eventually. Heat cycling, salt, moisture etc seem to work their magic on ceramic coatings. Then there is always the chipping aspects.

it doesn't have to be stainless, it can crack when you wrap it. If you wrap it and then it gets wet it will hold moisture in there and with all the heating and cooling it will rot the pipes.

works great just not ideal for a daily or a rally car.

there is a spray that goes over the wrap to seal it from moisture. its probably made my the same company that makes the wrap. REI or something? i dunno

I haven't had any experience with the spray for moisture protection but if it works it works.