Bnjmn

I was reading on the Burns site that they don't recommend aluminum for exhaust piping. Why would they say this? I was thinking of using aluminum after the catalytic converter- is this a bad idea?

Thanks
Ben

GraphiteAccord

it'll melt.

Overblown-Teg

I wondered that also. maybe just for the muffler.. My muffler does not get very hot.. I would say less hot than my intake manifold..

Tinker219

the ultimate combination for exhaust materials on a turbo charged car would be a
Heat-wrapped turbo manifold and turbo paired with an un wrapped aluminum exhaust. This will utilize pressure differences between hot and cold, and will allow quicker spool, more hp, etc.
BUT, the tricky part is keeping the aluminum by the turbo in one piece. Someone try it..if nobody does in the next month, I will on my new setup...

rioninja

nice... thats good thinking. heat differences would almost suck the exhaust out, in a matter of speaking.

Bnjmn

Come on...I think you guys are full of baloney. A cat. converter's operating temp is around 600 degrees. 6061 Aluminum has a solidus temp of 1080 degrees F. Anyone ever put an EGT probe around the end of the downpipe? I'd be really surprised to see anything that would melt aluminum.

meanteg

Yeah, why no one does that ? I wanna know too.

Bnjmn

Regarding the temp differences and having the Al section "suck" out the hotter exhaust- is this really going to happen? The Al exhaust piping wouldn't run any cooler than a comparable piece of steel- if anything it would run hotter since Al is a much better conductor of heat than steel?

xci_ed6

That is the point. it will conduct the heat from the exhaust to the atmosphere through the tube walls.

-Dustin

Tinker219

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by krustindumm &raquo;</TD></TR><TR><TD CLASS="quote">That is the point. it will conduct the heat from the exhaust to the atmosphere through the tube walls.

-Dustin</TD></TR></TABLE>
Yep. Im not sure how great of a difference it would make, but just basic physics laws pretty much proves that it will make a difference.

Full-Race Javier

yes, in theory it would work. u have to also consider that exhaust gasses and by products of combustion (like water) can shorten the downpipes life by corroding the material. AL will conduct more heat than mild steel and ss.....but it wont be able to withstand the harsh conditions like stainless can. u have to make comprimises

AL 6000 series:
-thermal conductivity=<u>166.9 W/m-K</u> or <u>1160 BTU-in/hr-ft²-°F</u>

Mild steel 1000 series:
-thermal conductivity=<u>51.9 W/m-K</u> or <u>360 BTU-in/hr-ft²-°F </u>

Stainless 304L:
-thermal conductivity=<u>16.3 W/m-K</u> or <u>113 BTU-in/hr-ft²-°F </u>

stierhund

aluminum can withstand the conditions just as well as steel if your talking about exhaust gases but not the temp changes... wether or not it will melt between 1080 and 1220 F is not the point... its the fact that it goes through temp changes daily and the structure bends quicker, but I bet that thick aluminum would hold up if it were welded well, and thats not easy to do

tony1

I've seen it done after the first bend on a drag car. The first bend takes most of the heat and you can do aluminum from there. This is on a drag car though, i don't think it'll last too long on a street car...

Tinker219

I think Im going to try this on my SRT4. 15k miles since Dec. 1st of 03, I drive a lot!
Back from the dead

xci_ed6

I forgot I even posted in this, let us know how it works!

tony1

I did it on Rado's car, we'll see how it holds up. If nothing else, it's super light!!

Tinker219

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote"> If nothing else, it's super light!!</TD></TR></TABLE>
Thats my thought on the PIG peon...
just have to flange for mufflers is the only drawback.

dasher

Ti exhaust is light also , but like aluminum doesn't hold up very well ... I guess its a great Idea it you don't mind changing your exhaust every couple years...

... I also was about to fork out the cash for an Aluminum or Ti exhaust for weight issues ... then realized that the exhaust weight sits so low to the ground that it wouldn't help handling that much ... Thats why i purchased a civic for my engine swap which doesn't have a sunroof... 30 pounds less up top where it counts!

macrosshn

iTrader: (1)

Zombie---back from the grave. I was definitely going to buy a JIC Bullet but I guess I'll buy a SS version. Can't really afford to spend 500+ on a new exhaust every couple of years.

dasher

yep, thats exactly what I was thinking ... Their is a point of diminishing returns, if you have tons of dispossible income then go for it though.

tjbizzo

You wouldn't need to get the aluminum hot enough to melt it, just hot enough to anneal it, because once it is in a soft annealed state it will turn to **** in very short order. This won't happen to Ti in an exhaust, and although Ti is more expensive it is much tougher and much more corrosion resistant.

dasher

TI is brittle and will dent easily however ... but I agree with you that Ti will hold up better then AL...

here is an idea:
... Inconel anyone? $$$$$$$$$$$$$$$$$$$$$$