My latest mod. idle hands are the devil's playground
 

I'm going to prefice this by saying i am in NO WAY going to reproduce, market, sell, give away, rent, lend or condone this.

Here is the latest from my twisted mind. you're saying to yourself " so what? you put a new exhaust on your 930", then you say, "is that a coating on the pipe? looks silver". Well aluminum is silvery in color

http://forums.pelicanparts.com/uploa...1269807981.jpg

yes, it's aluminum. from the flange to the tailpipe tip.
http://forums.pelicanparts.com/uploa...1269808210.jpg

http://forums.pelicanparts.com/uploa...1269808233.jpg

http://forums.pelicanparts.com/uploa...1269808249.jpg


yes, i am aware aluminum melts in the 800* area. Yes, i am aware for road racing this would NOT hold up AT ALL. But it's all in fun and thats what hor rodding is all about.

Sounds pretty good as well.

Yup, idle hands. Nice work.

Nothing wrong with experimenting and trying something different, keep at it!

You may see temperatures 1000*F higher than the melting point of aluminum in the neck area. Please show pictures of what the looks like as I can't quite imagine it.

the flange off the turbo is 1/2" thick aluminum. The tubing going to the muffler is .120" wall but the muffler is only .083" (we'll see how that holds up). The real unknown is how well the "U" turn will hold up. It's a "donut" we sell and it's really for intercooler piping and .065" wall. It provided me with the tightest radius in one piece but if it blows out i'll replace it with 2 90*'s in the thick wall. The car sounds good, i'll video it and post for all to hear.

Mad doctor at work! Love it.
Drag racers have been doing it for years. Why not try on a Porsche? What's the worst that'll happen -- it'll melt at the turbo and get loud?
Go for it!

I wish I could Tig like that!

true.

funny thing is i had just a 24" long straight pipe with no muffler on it before. It weighs 5.75 pounds. This whole contraption weighs 5 pounds and the car sounds much better

Nothing ventured nothing gained. As a one-off in a specific lower-than-tyical heat application it may last for a little while. That design is pretty much how my mufflers look and they weigh 12 pounds in 321 stainless. I would love to use aluminum as it is less expensive and lighter but it is nowhere near as durable as 321. You have seen those pictures of cherry red glowing turbos yes? That would turn your muffler into a vulcano.
Is your muffler packed or a perforated chamber?

Maybe you could give the inside ceramic coating if there is a process like powdercoating using ceramic. I guess that would require a "firing" that would melt Aluminum. Maybe a liquid dip?

I thought about some sort of coating on the inside but not sure what it would do to the muffler packing. We made the muffler out of perforated aluminum rolled into a tube shape then stuffed into the 4" tube with stainless packing material.

Brian, I did use your design for this set-up as it looks to give a bit quieter exhaust note due to the longer tubing. I'm going to the drag strip Wed night so we'll see if it stays on.

If your engine is in good tune with propper AFRs you should not see crazy heat like some of my mufflers have been exposed to. I would LOVE to use aluminum but it just isn't practical for all the various applications and range (or lack of) of tune.
Please do report back as I have never personally seen aluminum used in a turbo application. N/A typically produces a lot less localized heat.

As an FYI tidbit,

Inconel (Nickel alloy of ~30% Chrome and about ~5% Iron) is used for headers to save weight. It is actually similar density to Stainless Steels but it has a much higher resistance to heat. It is stronger (by weight) than SS at high temperatures. Therefore, F1 teams or high-budget racers can use paper-thin Inconel tubing to save on materials and weight. The problem is that it work hardens quickly and is very easy to fold/bend with tube walls than thin.

alot of my drag racing customers use aluminum exhaut on their turbo cars. They are after light weight and low price. Even if they have to replace the pipes at the end of the season it's still a whole lot cheaper than exotic materials. I keep my a/f on the fat side (10.5 @ WOT) so we'll see how well it holds up.

I would never recommend aluminum for road racing or any kind of extended WOT situations

That is a great application for this material, short term high performance.

We worked up a set of headers in inconel. Cost for materials alone was going to be $5000. Wow!

yikes

Brian, did your customer actually go ahead with the inconel system? Bragging rights or to save 2 oz? Where can I find customers like this.

A friend used aluminum for the rear half of the exhaust on a turbo road race car. To my surprise it lived.

The inconel headers were bagged by the client due to a personal issue that affected financing. He did pay for all the R&D work and some fixturing costs which was very nice.
LOVE the ditty under your screen name.