Welcome to the North American Subaru Impreza Owners Club Sunday July 5, 2015
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Custom Fabrication, Welding & Tools

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 12-25-2010, 12:16 AM   #1
scubydrew
Scooby Specialist
 
Member#: 32609
Join Date: Feb 2003
Vehicle:
2005 saab 9-2x
rhd ej20tt sold...

Default Aluminum exhaust

As controverial as the aluminum exhaust is I built this just to see for myself effects of heat transfer thru the exhaust. I was suprised to find that it doesn't sound much different then it's stainless counterpart. This catback weighs in at 8.2lbs! Here's a few pics





* Registered users of the site do not see these ads.
scubydrew is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 12-25-2010, 12:27 AM   #2
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

Structurally I don't see any issues, but I'd like to see dyno plots back to back to see if there's any measureable difference due to the aluminum removing LOTS of heat from the exhaust gasses. In theory it can create backpressure, but in reality it may not even be measurable. Or maybe it is?
KillerBMotorsport is offline   Reply With Quote
Old 12-25-2010, 01:28 AM   #3
PHATsuby
Scooby Guru
 
Member#: 13617
Join Date: Dec 2001
Chapter/Region: MWSOC
Location: MN
Vehicle:
2001 Legacy GT back
to stock is a project too

Default

I think the concern is with the effect of heat cycles on aluminum vs. stainless/steel. I'll be curious to see the result. What do you plan to do to test this?

The piece looks very nice with great attention to detail(the extra thickness for welding the hangers for example).

Great job.

Ben
PHATsuby is offline   Reply With Quote
Old 12-25-2010, 01:34 AM   #4
scubydrew
Scooby Specialist
 
Member#: 32609
Join Date: Feb 2003
Vehicle:
2005 saab 9-2x
rhd ej20tt sold...

Default

Thanks Ben. yeah I don't plan doing any tests. This was built purely out of curiosity.
scubydrew is offline   Reply With Quote
Old 12-25-2010, 07:27 AM   #5
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

I like it, just curious of the effects is all. I've seen this done by a few others lately and I wouldn't be suprised if the interest brought a few pieces to market.
KillerBMotorsport is offline   Reply With Quote
Old 12-25-2010, 04:28 PM   #6
sorrowfulkiller
Scooby Specialist
 
Member#: 170439
Join Date: Jan 2008
Location: Sioux Falls, SD
Vehicle:
I <3 Lamp

Default

Quote:
Originally Posted by KillerBMotorsport
I like it, just curious of the effects is all. I've seen this done by a few others lately and I wouldn't be suprised if the interest brought a few pieces to market.
I'd buy one if a straight through design was kept with a turn down on the muffler. I'm curious to see if it would stand up to as much abuse as stainless though
sorrowfulkiller is offline   Reply With Quote
Old 12-25-2010, 04:34 PM   #7
tobylazur
Scooby Specialist
 
Member#: 150289
Join Date: May 2007
Chapter/Region: SWIC
Location: PHX, AZ
Vehicle:
2006 SV650N
1972 Travelall

Default

Let us know how it works down the road. I'm really interested in the idea of an aluminum exhaust, but I would think they wouldn't last very long.
tobylazur is offline   Reply With Quote
Old 12-25-2010, 04:43 PM   #8
scubydrew
Scooby Specialist
 
Member#: 32609
Join Date: Feb 2003
Vehicle:
2005 saab 9-2x
rhd ej20tt sold...

Default

Quote:
Originally Posted by tobylazur View Post
Let us know how it works down the road. I'm really interested in the idea of an aluminum exhaust, but I would think they wouldn't last very long.
I will and this is the reason I wanted to make this. I wanted to see first hand. Putting the he said, she said to rest.
scubydrew is offline   Reply With Quote
Old 12-29-2010, 05:16 AM   #9
Uncle Scotty
Visiting NASIOC Timeout
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK buy Nates beans
westcoastroasting.com

Default

exhaust gases are quite corrosive and the pipes will corrode from the inside out

It'll look ok from the outside one day and fall to bits the next


that is why aluminum isnt very popular for this kind of thing...and stainless and titanium are
Uncle Scotty is offline   Reply With Quote
Old 12-29-2010, 07:19 AM   #10
Storm
Scooby Guru
 
Member#: 5218
Join Date: Mar 2001
Chapter/Region: MWSOC
Location: SAUL'S Motorsports
Vehicle:
96L Most Over-
Developed Beater

Default

^^^ Cool....so it'll get even LIGHTER? I think I may build one for the weight savings. The car doesn't see daily driving anymore anyway.

What's the wall thickness of the tubing and approximate $/ft.?

Thanks,
Jay
Storm is offline   Reply With Quote
Old 12-29-2010, 07:24 AM   #11
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

^ True. Could be a month or a year, could be 10 depending on many factors (grade of aluminum, thickness, EGTs, etc.). The only thing I would have done differently than scubydrew, is put a collar at the flange and used saddles at all the hanger locations. My guess is fatigue will be the eventual demise here.
KillerBMotorsport is offline   Reply With Quote
Old 12-29-2010, 10:44 AM   #12
Uncle Scotty
Visiting NASIOC Timeout
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK buy Nates beans
westcoastroasting.com

Default

Quote:
Originally Posted by KillerBMotorsport View Post
^ True. Could be a month or a year, could be 10 depending on many factors (grade of aluminum, thickness, EGTs, etc.). The only thing I would have done differently than scubydrew, is put a collar at the flange and used saddles at all the hanger locations. My guess is fatigue will be the eventual demise here.
yeah....Ive been around 'hot rodding' a while and I have known a few welders who fabbed up aluminum exhaust....most got the tubing for 'free' and some lasted a while some didnt

If you take the time to figure out where all the cracks are gonna happen and use an alloy that is more resistant to corrosion.....it may be a better idea than if you dont

I would drill a small hole in the low spot in the system to let the water out
Uncle Scotty is offline   Reply With Quote
Old 12-29-2010, 11:31 AM   #13
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

Good idea with the low point weep hole.
KillerBMotorsport is offline   Reply With Quote
Old 12-30-2010, 08:38 PM   #14
tobylazur
Scooby Specialist
 
Member#: 150289
Join Date: May 2007
Chapter/Region: SWIC
Location: PHX, AZ
Vehicle:
2006 SV650N
1972 Travelall

Default

The two I've seen were on race cars, and both failed due to heat and vibration
tobylazur is offline   Reply With Quote
Old 12-30-2010, 09:12 PM   #15
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

Quote:
Originally Posted by tobylazur View Post
The two I've seen were on race cars, and both failed due to heat and vibration
Probably no chance you have or can get pictures? I'd love to see those failures.
KillerBMotorsport is offline   Reply With Quote
Old 12-30-2010, 10:48 PM   #16
Gixx6
Scooby Newbie
 
Member#: 134563
Join Date: Dec 2006
Default

We have test around with aluminum exhausts. Mostly wanted to see what kind of heat they could take - not much, so the first part of the exhaust system needed to be stainless for around 3 feet. After that it's aluminum. Tried a few setups with just aluminum and ended up collapsing on the track haha.

Aluminum is much cheaper than stainless and of course lighter. So if it doesn't last the longest big deal and I'll make another
Gixx6 is offline   Reply With Quote
Old 12-31-2010, 12:05 AM   #17
tobylazur
Scooby Specialist
 
Member#: 150289
Join Date: May 2007
Chapter/Region: SWIC
Location: PHX, AZ
Vehicle:
2006 SV650N
1972 Travelall

Default

Quote:
Originally Posted by KillerBMotorsport View Post
Probably no chance you have or can get pictures? I'd love to see those failures.

One was the AFI S2000. The exhaust kept breaking on where it would split into two towards the back.

The other was the full race S14. I don't have the picture of where it failed, it was on my buddy's phone, but here's the written version

Quote:
after the race was over, the aluminum exhaust shattered, and cut open the p/s line. p/s fluid got under the car and exh lit it up.


it broke way up there by the steering rack
tobylazur is offline   Reply With Quote
Old 12-31-2010, 10:28 AM   #18
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

Thanks. Interesting stuff.
KillerBMotorsport is offline   Reply With Quote
Old 12-31-2010, 04:37 PM   #19
oguitar
Scooby Specialist
 
Member#: 206720
Join Date: Mar 2009
Chapter/Region: SWIC
Location: Albuquerque NM
Vehicle:
2002 WRX Wagon
Silver

Default

What type of Al alloy did you use?

http://www.azom.com/Details.asp?ArticleID=310

6063 or 5083 might work. Your Al exhaust looked really shiny though so either you polished it or used a different alloy. Just wondering.
oguitar is offline   Reply With Quote
Old 12-31-2010, 08:22 PM   #20
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

I would use 5052
KillerBMotorsport is offline   Reply With Quote
Old 12-31-2010, 10:25 PM   #21
silentvoice71
Scooby Newbie
 
Member#: 79660
Join Date: Jan 2005
Location: indiana
Default

Ive welding aluminum for a long time. The only thing I worry about was already talked about. When you heat up aluminum and cool it often it becomes brittle. Just like when you heat temper tools. They become brittle and instead of bending the just shatter. I'd stick with aluminum or if you just wanna go all out.... Buy some Ti and weld a nice one. Jmo.
silentvoice71 is offline   Reply With Quote
Old 01-01-2011, 04:27 AM   #22
Uncle Scotty
Visiting NASIOC Timeout
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK buy Nates beans
westcoastroasting.com

Default

Quote:
Originally Posted by KillerBMotorsport View Post
I would use 5052
this may be the best bet....but it will still crack

Some airplanes have apu exhaust ducting made of 5052
Uncle Scotty is offline   Reply With Quote
Old 01-01-2011, 10:55 AM   #23
pwrofdrm
Scooby Newbie
 
Member#: 129574
Join Date: Oct 2006
Chapter/Region: NESIC
Location: NY
Default

Here's my aluminum exhaust setup on my turbo S2000. For the reasons noted above, it was constructed of stainless steel from the downpipe back to the "Y" which also allowed me to use my resonator of choice.

No mufflers, just the Vibrant 12" resonator.





pwrofdrm is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS : STi Ver 7 Aluminum control arms Legacy Suspension/Brakes/Handling 9 02-09-2011 08:25 AM
FS : 4ea Billet Aluminum Hubcentric Spacers jbsurf1 Wheels/Tires 1 01-03-2011 03:28 PM
aluminum exhaust gaskets? gto7419 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 2 10-15-2008 08:22 PM
Aluminum Exhaust? TurboWRX32 Newbies & FAQs 7 07-29-2008 10:49 PM
Stainless steel or Aluminum exhaust? jay25RS Normally Aspirated Powertrain 7 06-10-2001 09:52 PM


All times are GMT -4. The time now is 04:24 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2015 Axivo Inc.
Copyright ©1999 - 2015, North American Subaru Impreza Owners Club, Inc.