Aluminum vs. Stainless Steel Intercooler Tubing

bennyboy26j

Active member
Joined
Oct 30, 2010
Location
Detroit Metro
TDI
2002 Jetta 1.9L TDI
Well I am at the point in my ALH build where I need to start planning my intercooler pipe routing and I got to thinking, which material should I use? In the past I have always used aluminum because it was light weight and I had all the room in the world to work with so size didn't matter. In all my searching on here, I have found both aluminum and SS. So I figured I would start a conversation with all of you about the pros and cons of each. Also, what size tubing would you suggest and why?

Thanks for your input :)
 

BigTurboAlh

Veteran Member
Joined
Jan 8, 2016
Location
Pa
TDI
06 ranger cjaa swap
most people think im nuts but use mild steel on most stuff i do. most people like aluminum for its light weight and heat dispensation. stainless looks nice but cracks sometimes. if i was doing a weekend car id to stainless or aluminum. dd i use mild steel but thats just my preference.
 
Last edited:

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Whatever material you decide to use, get a set of these to help in the mock up. They're a bit pricey but high quality and if you've ever done this kind of work without them, you won't hesitate at picking up a set (I think I have 3 different sizes)

https://www.icengineworks.com/product/2000series-tack-welding-clamps-set-4/

I'd go with 2" tube (not pipe) since it's commonly available and a tick bigger than OEM.

I've fabbed tubing with all 3 materials and mild steel is by far the easiest to work with, least expensive and a good coat of paint goes a long ways in keeping it from rusting out.

Stainless looks nice, stays that way, but is heavy and really unnecessary for boost piping in my opinion. Most difficult to cut/form, has the lowest heat transfer coefficient of the 3, and is more difficult to weld than mild steel, but easier than aluminum.

Aluminum is likely the best due to weight and heat dissipation (this works both ways as it absorbs heat equally well), but is the most difficult to work with - particularly the welding part but it scratches and dents easily as well.

Woolf Aircraft is a good source for the tubing and has most all sizes/materials in 1D CLR (really tight bend radius) so you can fit in tight places. Made in USA and fair prices as well.

http://catalog.woolfaircraft.com/viewitems/bent-elbows/aluminum-bent-elbows
 

Macradiators.com

Veteran Member
Joined
Nov 2, 2015
Location
Romania
TDI
2.0 CR 360hp
Only Aluminum for me , its light, its beautiful and for me the easiest to work with.
Stainless needs purging when welding, pita.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I like aluminum, even though it's tougher to weld up it's worth that much.

Realities of life say that I use mostly junkyard sourced 409 exhaust tubing, rust and all.
What aluminum I've got is mainly junkyard sourced as well, in the form of cold air intakes. Sadly it's all much larger than I'd use on a TDI.

Stainless is cool because you can burn it together with normal mild steel mig wire long as you don't care about it rusting eventually.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
Stainless needs purging when welding, pita.
Don't burn through!
adjusting down output inductance (or removing the capacitors) helps a lot with MIG, I hear low on-time pulse TIG does similar stuff, but I've only got transformer machines.
 

vtpsd

Veteran Member
Joined
Aug 15, 2013
Location
Vermont
TDI
03 jsw TDI, audi 90 AHU swap
most people think im nuts but use mild steel on most stuff i do. most people like aluminum for its light weight and heat dispensation. stainless looks nice but cracks sometimes. if i was doing a weekend car id to stainless or aluminum. dd i use mild steel but thats just my preference.
I use mild steel exhaust tubing and MIG it togeather. Then I smooth the welds out and coat it with this.


The stuff drys with a hard, textured rubbery surface. People always compliment my piping and ask what it is. It ends up looking somewhat like and OEM product when the piping is fit nicely.

I would use aluminum if I had a TIG.
 

bennyboy26j

Active member
Joined
Oct 30, 2010
Location
Detroit Metro
TDI
2002 Jetta 1.9L TDI
So far I am leaning towards aluminum. I have a TIG welder, and will be getting a MIG soon with a spool gun so I can weld aluminum with either. I am certainly not good at welding, but I can make things seal. I like the idea of grining down the welds and using that textured paint that vtpsd suggested. Its kinda cheating (according to the welders I have worked with), but you gotta do what you gotta do. Thanks for the input so far!
 

amafrank

Well-known member
Joined
Feb 17, 2009
Location
USA
TDI
'06 TDi jetta, '09 TDi jetta wagon, 15 TDi GSw
It depends more on what you're capable of working with and what you're attaching it to. If you're welding to an aluminum intercooler you should use aluminum obviously. If you're making connecting pipes that will be joined with rubber sleeves it doesn't matter. They all have their advantages. I like mild steel for a lot of stuff but it can rust inside where you really don't want rust unless you paint inside and out. Stainless and Aluminum won't have that problem. Powder coating can fix that issue too. Mild steel is easier to weld even with a glue gun (mig) though I'd like to have access to the insides of the welds for cleanup.

Frank
 

smoking

Well-known member
Joined
May 9, 2018
Location
Europe
TDI
A5 3.0 TDI quattro + Golf II AFN + Golf IV ASZ
I had an old Nissan that had mild steel IC piping painted black and eventually it did rust.
 

bennyboy26j

Active member
Joined
Oct 30, 2010
Location
Detroit Metro
TDI
2002 Jetta 1.9L TDI
Matt is a friend of mine, I am a far cry from his skills when it comes to welding anything. I will probably be painting mine regardless
 

Votblindub

Veteran Member
Joined
Dec 22, 2010
Location
NY
TDI
MK4 Jetta Wagon
I've seen both on a lot of turbo cars. Most of the time it's aluminum piping(some welded and some with silicone couplers). Stainless(or some other metals) are used for those very pretty lobster-tail pipes with the super tight radius curves, because they show the welds with the blue and gold colors on them more. Some of it is aesthetics...well, let's be honest here, MOST of that is aesthetics or to show off some welding skills. My personal piping will be aluminum(for the wagon build). It's less weight(saving like 2lbs here HAH!), aluminum doesn't have the rust issues that steel tends to have(i'm in the northeast), but I'll paint it with the stuff vtpsd suggested. A big factor of it for me is that I already have a bunch of aluminum piping already. From what i've been reading, aluminum has better heat dissipation properties compared to steel. I am also not running enough PSI through it, my pipes won't split, so I don't need stainless there.
 
Top