kas83

First off, does any make a stainless steel exhaust that has a 4" downpipe that will bolt to all the aftermarket chargers? My truck sits a lot, and is in WI yearround, so I want an exhaust that won't rot out. Secondly, has anyone considered, or made, an exhaust manifold out of stainless? I've been reading about HTT's SS housing, and it seems like the manifold and housing would be a great setup due to the thermal properties of stainless steel. Plus I think it would be pretty cool when the manifold changes colors after it gets hot. Thanks for any input.

gmctd

409SS, which is what most oem Diesel exhaust is made from, looks like regular exhaust pipe, but is more rust resistant - 4" price ~500bucks turbo back

308, 316SS, which is shinier, can be highly polished to a chrome luster, is the high-end replacement - ~900bucks turbo back

Check the vendors - MBRP, etc for options

SS exh manifold - don't know of any, other than SS headers - cast iron is the most stable for exhaust manifolding, particularly where it must support a load, such as the turbo - cracking problem comes when 4wd and lifted trucks go splashing thru high-water, where the cold water is forced around the shock tower into the engine bay - doesn't take much of that to crack the long Cummins manifold - normal rusting problem is minor, as the inside of the manifold is coated with soot and other byproducts from burning light oil - an annual coating of VHT paint should help with that - or have the manifold cleaned, blasted, and ceramic-coated - if done on a clear dry day - no humidity - the coating will adhere well and last long, long as you don't crack it or chip it during wrenching

biododge1

i had stainless manifolds on my car-looked trick, but they cracked-repeatedly

2500superram

i just installed a 409ss 4" turbo back from summit yesterday($400 shipped).ordered it wendsday and it was sitting on my door step friday.409ss will still get ugly,but last alot longer then aluminzed steel.
the only way i can see a ss manifold working on this truck is with alot of support for the turbo.the way the turbo hangs off the side,would most likely make it crack easy.i run a 321ss manifold on my supra with a bigger turbo then this truck,but it is also top mounted t4 with support.it also doesn't shake and vibrate at all

gmctd

I just installed the 409ss summit setup, also - free shipping, polished 316 ss exhaust tip included, fit perfectly, excellent welds and bends, really excellent 4"-thru ss oval glass-pak muffler, all ss brackets fit oem hangers, all hi quality - only downer is really noisy, for my tastes - gonna modify the soot trap to 4" in, reinstall it if I can't get another muffler from them - sheesh! - that oem 3" system is one more hea-vy!

dodgediesel

I wouldn't waste your time on the ss exhaust as it will spot rust. 2500 Superram, watch the swearing, they will get ya good!!

wurkenman

I am a machinist by trade and all we work on at my shop is stainless. Do not make a stainless manifold it WILL NOT take the extreme temp changes. It WILL warp and crack and there is no way to control it.

2500superram

mine seem's to be quiet.i can't hear an exhaust note over the motor.i did have a little leak after the muffler and needed to tighten the clamp a bit more.i'll have someone drive my truck down the road,wanna hear what everybody else does


thanks for the head's up.i didn't realize i typed any,must have been asleep or something.i edited it out though

kas83

But it won't rot completely out as fast as an aluminized exhaust. I don't care if it's ugly, as long as it doesn't have holes in it.


So it's a no-go on the manifold, thought I'd ask.

gmctd

Pull yer manifold, have it blasted and ceramic coated in the color of choice, or shiny, like chrome - can also do the turbine snail and exhaust elbow

XLR8R

Really, it depends on the alloy used and it's method of construction.

Castings don't thermally cycle as well as forgings, which don't perform as well as DOM-type tubing.

Higher nickel/chromium alloys such as 316SS fare much better in an elevated temperature envelope than 400 series do; essentially, higher temperatures increase the rate of oxidation of the parent metal.

Since 304 stainless steel conducts heat less efficiently than carbon steel, yet deforms more under the same thermal load - it is subject to significant dimensional stresses. These performance characteristics are beneficial in a corrosive, high-temperature structural application such as an exhaust manifold. Aesthetics are considered to be a fringe benefit.
Of course, special consideration should be given to the potentially large structural loads imposed by the turbocharger(s)' weight, as well as the severe work-hardening vibratory environment of the CTD.

The bottom line is that the nickel market has driven stainless steel prices up dramatically in the last couple of years, to the point where it costs almost 10 times what iron does.

I prefer SS headers over cast iron manifolds, both for operating performance and ease of repair.

kas83

So do you think I was on the right track with my thinking of the performance? I understand that it is a very harsh environment and that it may not hold up well. Was thinking there might be some way to make it work.

Also, I was never worried about a cast iron manifold rotting out. I was just curious as to whether any performance could be afforded with the use of stainless steel. My plans have been to get a 3 piece, get it and the turbine housing ceramic coated, and have fun. Wanted to check into the alternatives.