What is the perfered material for running IC pipes? - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• What is the perfered material for running IC pipes? by subsonic on 16 Jun, 2007 22:00
• Like the title says.  I guess if is listed, from the most to the least.  
  Silicon, aluminum, copper, pvc...?
  As a add on, what about the ID size of the pipe?  Is bigger better?
  
  So do you want a material that will radiate / give off heat going towards the IC, and a insulated pipe coming back to the intake?  Or should it all be the same?
  
  Has anyone ever tried to mount a IC under a hood scoop?  Not sure how you would continue the air flow out of the engine compartment.  Just thought it would reduce the overall length of the pipe runs. Just a thought.
• #1 by OM617 on 16 Jun, 2007 23:44
• Aluminum.
  
  Also, you want the insulation to be the other way. Insulate going to the intercooler and none going to the engine.
  
  The hotter the air going to the IC, the more efficient it will be at removing the heat.
• #2 by jackbombay on 17 Jun, 2007 01:11
• Quote from: libbybapa

  There is no situation where hotter air entering the intercooler will create colder air out of it.
  
  Andrew

  
  
    Yep.
  
    Aluminum pipes are best as Al transfers heat very effectively for additional cooling.
• #3 by jimfoo on 17 Jun, 2007 10:52
• So why don't people also put finned heatsinks on their tubing? Might not even need the IC that way.  :lol:
• #4 by jtanguay on 17 Jun, 2007 12:30
• Quote from: "jimfoo"

  So why don't people also put finned heatsinks on their tubing? Might not even need the IC that way.  :lol:

  
  
  heatsinks are quite expensive.  plus if you put a heatsink inside the engine compartment you will most likely get heatsoak.  (except maybe at highway speeds where fresh air is constantly flowing in)
  
  imo insulating the IC pipes would give some gains with aluminum, especially on hot days.
  
  the same concept is used on refrigerant systems.  just look under the hood.  does the high/hot side have any insulation on it??? nope, because chances are the temps there are greater than the temps under the hood. (if not, you might want to get that fixed  :lol: ) after the high pressured (high pressure creates heat) is flowed through the condensor to cool it, it then flows insulated to the evaporator, where the expansion valve controls the flow of liquified refrigerant to be sprayed in.  the liquified refrigerant then evaporates, taking with it a great amount of heat, and is then flowed back into the compressor to complete the cycle.
  
  that should make sense to everyone.  the only difference between refrigerant system and your intercooler, is the matter being compressed, and the pressures at which they are being compressed.  (air vs hydrocarbon refrigerant & 10-20 psi vs 300 or so psi)
• #5 by Vincent Waldon on 17 Jun, 2007 12:53
• My opinion:  the entire purpose of an IC is to cool down the air between the turbo and the intake... anything you can do to lose heat along the way is a good thing.
  
  So, I can't personally see any reason to insulate any part of the tubing... the more heat you lose along the way the better.  And I'd paint it flat black to radiate as much heat as possible.... an old VW bug trick that can actually make a real difference. Shiny/chrome is terrible at losing heat... as Beetle owners with fancy chromed rocker covers soon discovered.
  
  If you had to route the tubing over a hot part of the engine you might want some kind of a heat shield.
  
  Finally, ideally I'd put the IC anywhere but in front or behind the rad... you're removing heat from one part of the engine and transferring it to another part of the engine.  Obviously the physical realities of each situation sometimes dictate otherwise, but if you can avoid it doesn't make much sense to me to go to a lot of plumbing trouble if you're just moving heat around !!
  
  Just my CDN $0.02 worth...
  
  Vince
• #6 by subsonic on 17 Jun, 2007 14:36
• So aluminum gets a few votes.  Whats with all the big silicon tubes you see on IC setups?  Is that just for the flash of purple neon or dayglow green?
  
  As far as painting the pipes, I live in New England.  There are still lots of old homes that have the big cast iron steam radiators.  People are always painting them to try and get them to blend in with the room.  I hear from all kinds of HVAC guys that this screws up the heat transfer.  They should not be painted.  Does the same apply here?
  
  What about size -ID-.  Is bigger better? Should it be max dia. of the intake-outlet opening of the  turbo / IC / intake, or should it neck down to meet them to speed up air flow?
• #7 by Benjamin on 17 Jun, 2007 14:49
• i know aluminium is very good.
  but do anyone have any idea "how much better" it is than metal?
  
  i'm making a intercooler also, i can make the metal pipes myself, or i can give my €$€$€ to someone who can work with a TIG and let him make the alu's.
  
  is it realy worth it to have those aluminiums?
  
  Greetz, Benjamin
• #8 by Vincent Waldon on 17 Jun, 2007 14:52
• IMHO thick enamel house paint is probably more of an insulator than anything... coating something you want to radiate heat with an insulating layer is probably not the best, but of course there are home-decorating considerations to make !
  
  Air-cooled guys learned that a light coat of flat black (Tremclad is good since you don't need the thickness of an additional primer coat) seem to give optimal heat transfer with a minimum of insulation effect.
  
  Someone once pointed out to me:  good frying pans are usually flat black, partly to transfer heat efficiently to your bacon.  Kettles are chrome partly to keep heat in and boil water quickly.
  
  Again, just my theoretical perspective as an ex-aircooled guy... I don't actually have an IC on my beast at the moment.  When I do it will be mounted away from the rad and plumbed with the biggest diameter flat black tubing (aluminum, thin steel, I doubt it matters as long as it can carry the pressure) I can fit under the hood.
  
  Vince
• #9 by rallydiesel on 17 Jun, 2007 16:41
• I think silicon is popular just because it is easy to work with. Aluminum tubes need to be specific to the car and welding and fabricating the bends is not something the home "tuner" is capable of.
• #10 by BlackTieTD on 17 Jun, 2007 17:22
• i don't think it was mentioned the obvious, that aluminum is a lot lighter than steel, which is another clear benefit if this material.
  
  

  Quote from: "Vincent Waldon"

  When I do it will be mounted away from the rad and plumbed with the biggest diameter flat black tubing (aluminum, thin steel, I doubt it matters as long as it can carry the pressure) I can fit under the hood.

  
  
  will there not be a larger pressure drop by using such large diameter tubing?
  
  where else under the hood can you get good airflow with minimal heatsoak than in front of the rad?
• #11 by Vincent Waldon on 17 Jun, 2007 21:21
• Location is definitely  a challenge.
  
  The GTDs have a small IC mounted on the driver's side with a hood scoop.... the other location I like is long and thin under the rad in the front big bumper (mine's a A2)
  
  Have to do some research about tubing but my guess is that the limiting factor is size that actually fits under the hood.  I think flow is a consideration as well as pressure... and they are generally inversely proportional to each other as tubing diameters change.
• #12 by jimfoo on 18 Jun, 2007 00:57
• One reason people use silicone is that it handles heat very well. If you were running a lot of boost, the air might get too hot for rubber tube or connectors.
• #13 by subsonic on 18 Jun, 2007 23:55
• So, if we increase or decrease the size(dia.) of the IC pipes this must have an effect on performance would'nt it?  
  If a turbo is pushing 20psi, the actual pressure must be relevant to the size of the area holding it right? I am thinking of an example of my bike tires.  My road bike tires I pump up to about 120psi.  My mountain bike tires roll at about 40psi.  Both tubes are different diameters.  The same volume of air and needed pressure to hit 120psi in the road tire would probably only give me 20psi if I transfered it to the mountain bike tire.  I would also not have to work so hard to fill the bigger tire to this level.  I am guessing that the air volume would slow down though as well in the bigger diameter.
  Kind of an odd analogy, but I 've been up for 30 hours so I am kind of punchy.
  Does the same sort of volume(cfm) v.s pressure(psi) thing relate to the turbo and IC tubes? If a turbo is putting out 20psi into a system with a diameter of say 1", is it really the same 20psi if the diameter is now 2" or is more air being moved?  Could the same amount of air being moved with the 1" now be achieved with the 2" but at say a pressure of 15psi instead of 20psi?  The 1" 2"  20psi thing are all just pulled from the air just as examples.
  I was wondering with this line of questions if this would mean that the amount of boost someone says they are running is really accurate? 20psi at what volume, or what velocity?  
  The sleep monster is starting to win the fight and kick my ass, I'm off to bed..............zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
• #14 by jimfoo on 19 Jun, 2007 01:09
• Small pipes will restrict volume, with the end result being less air at the intake, or the turbo having to work harder to get that same amount there at the same pressure. If small pipes were good, you wouldn't see 3" and larger pipes for sale.