Aluminum exhaust vs. stainless exhaust

[ramsack]

I would think differing metals would sound different with an exhaust for the same reason that certain metals are preferred for certain brass instruments.

I would also consider a minor effect. The aluminum is going to cool the gas faster since the aluminum itself will let heat go faster than steel, making a more dense exhaust gas, and a slight loss in power. Is it enough to outweigh the weight savings? Who cares.

If you really want to go for something exotic, go for titanium or inconel.

 

[snowborder714]

Titanium I've seen has the same properties as aluminum and is priced between stainless and inconel. I've read Titanium is also harder to weld. And there's probably no way in hell anyone on here would spend the moolah on inconel!!!!

 

[TSi Kid]

I would think differing metals would sound different with an exhaust for the same reason that certain metals are preferred for certain brass instruments.

Full brass exhaust, i'm doing it!

Titanium I've seen has the same properties as aluminum and is priced between stainless and inconel. I've read Titanium is also harder to weld. And there's probably no way in hell anyone on here would spend the moolah on inconel!!!!

I've heard of titanium exhausts but never iconel, and if I wasn't still laying in bed hungover i'd look it up haha

What's the difference between titanium and iconel vs SS or aluminum?

 

[ramsack]

Inconel is supposed to be able to be really super thin and take a crap load of heat. Obviously as expensive as it is, it's mainly used in F1 exhaust. I'd imagine copper would be a pretty interesting-sounding exhaust and really get rid of the heat.

 

[TSi Kid]

Inconel is supposed to be able to be really super thin and take a crap load of heat. Obviously as expensive as it is, it's mainly used in F1 exhaust. I'd imagine copper would be a pretty interesting-sounding exhaust and really get rid of the heat.

Could you imagine how expensive copper would be though? The benefit, however, is by drilling a few holes, you could turn your exhaust into a brass instrument; and who doesn't want that?

 

[ramsack]

I don't think copper would be too high priced. No point in making it super thick, either, since it's going to definitely and easily fail. Luckily metals have fallen and are just starting to now go up again. I hope they don't go up too fast.

 

[snowborder714]

STM GALLERY - Brad's 99 GST

I just called STM and got some more info on this exhaust.

Pipe size: 3"
Wall thickness: 1.5mm (0.059")
Muffler: Vibrant
Clearance issue running under rear end for FWD car? Nothing yet
How much of exhaust is aluminum? After downpipe is when the aluminum section starts (SS downpipe)

 

[TSi Kid]

How much of exhaust is aluminum? After downpipe is when the aluminum section starts (SS downpipe)

Know of anyone running an aluminum down pipe?

 

[snowborder714]

No DSM owners have one that I know of. The temps right off the turbo would be too hot (at least for my liking) to be putting through aluminum.

 

[TSi Kid]

No DSM owners have one that I know of. The temps right off the turbo would be too hot (at least for my liking) to be putting through aluminum.

Even if you were to heat wrap the down pipe and the manifold? Hmm..

 

[ramsack]

That would make things worse. Heat wrapping and such is better for performance, but harder on the metals.

 

[TSi Kid]

That would make things worse. Heat wrapping and such is better for performance, but harder on the metals.

Sorry, I didn't mean to say heat wrapping the downpipe. I could put a heat cover on the compressor housing, and then heat wrap the manifold to minimize the heat that the downpipe would see.

What temperatures does aluminum start to become unsafe to use in regards towards an exhaust application?

 

[snowborder714]

You have to consider internal heat just as much as external heat. Think of how hot exhaust gasses are.

Aluminum's melting point is 1220 °F.

 

[TSi Kid]

You have to consider internal heat just as much as external heat. Think of how hot exhaust gasses are.

Aluminum's melting point is 1220 °F.

Sorry for all the questions, i'm not trying to post bump; physics just gets my rocks off.

I like the idea of copper or iconel though, I wonder how much an exhaust like that would cost.

 

[ramsack]

Inconel would cost a few thousand. It's one of those things where you can't just see prices in google searches, you simply get these manufacturers where you fill out a quote form, and they e-mail you a price.

 

[TSi Kid]

Inconel would cost a few thousand. It's one of those things where you can't just see prices in google searches, you simply get these manufacturers where you fill out a quote form, and they e-mail you a price.

I mean, I make some pretty poor choices in my life, but I could never rationalize that.

How much do you think copper would be?

 

[ramsack]

A few hundred for copper. Closer to a grand.

 

[snowborder714]

Inconel 600 in 3" OD from Pacific Alloys is $298/foot. I called as I couldn't find any pricing online from anywhere and was interested.

 

[TSi Kid]

Inconel 600 in 3" OD from Pacific Alloys is $298/foot. I called as I couldn't find any pricing online from anywhere and was interested.

I mean, that's a ridiculous amount, but if it sounded sexy, and would weigh a sizable number less I would waste the money.

Copper doesn't sound too rediculous, has this ever been done before?

 

[ramsack]

What kind of wall thickness is that?

I don't see anyone attempting copper. It's heavy and soft. It would need to be insanely thick to deal with the heat. In the end it would probably weigh more than steel.

 

[snowborder714]

I don't remember, but I think it was pretty darn thin (.02ish maybe?).

 

[ramsack]

That would be pretty damn sweet of an exhaust, turbo back.

 

[TSimage]

A few hundred for copper. Closer to a grand.

Not even close...

A copper exhaust is probably gunna run a few hundred at best.. But why is it even being seriously discussed . TSi Kid is trolling hard in this thread .

On a side note, I run 4" aluminum exhaust and there were never any issues. The NSX and RX8 had Titanium exhaust on them and there is a definite change in sound that is more subtle with aluminum. Aluminum seems to slightly 'dampen/muffle' the sound as most softer metals would.

 

[ramsack]

It is close because you're not going to be able to run some thin-walled crap and have it last. You're going to have to use some damn meaty pipe for it to last. It would cost over $500 easily.

 

[99gst_racer]

I built a 3.5" turboback from 20-gauge SS a few years ago. It ended up weighing exactly half as much as the 3" turboback that it replaced. But the cost of the materials and muffler from Burns Stainless was over a grand. It was a PITA to weld too.