Rabidchimp Intake pipe Aluminum?

[batmobile]

Hey for all of you people who have the chimpy intake pipe. Is it Aluminum or is it steel that has been Aluminized? In the description on the web site it says aluminized, Is that the ceramic coating that they put on it that makes it aluminized or is it just the description?

[SupraWes]

I think its aluminized exhaust tubing to cut down on the rust. The pipes have a powdercoated finish on the outside.

[batmobile]

Yes, But are the Intake pipes aluminum pipe, Or steel?

[SupraWes]

Steel

[batmobile]

If the pipes were made of aluminum It would dissipate the heat faster, Therefore allowing a little more HP Due to coldness in the intake pipe. Not only that, but they are a little lighter. But the cost of mass production of aluminum intake pipes would be outrageous. I have 48 inch 3 inch diameter pipe that Im going to attempt to bend and replicate the RC intake pipe. wish me luck.

[FWDsux]

If the intake is aluminum, it will pick up heat faster than dissapating it. The ambient air around the pipe is hotter than that of inside, so where's the heat going to go? It's going to heat up the intake air. So basically the same as steel...unless you wrap it with reflective insulation.

[batmobile]

aluminum cools faster than steel does, Steel once heated up will take a lot longer to cool than aluminum. Its a win/Win situation with aluminum.

[Phoenix]

aluminum cools faster than steel does, Steel once heated up will take a lot longer to cool than aluminum. Its a win/Win situation with aluminum.

That's right. Aluminum is a way better material to use than steel. It has a lower specifec heat capacity. Let us know how this project goes. Good Luck.

[batmobile]

Thanks Phoenix, I need to think of an Idea to bend the pipe, Since I dont know anyone with a mandrel Bender. When Im done I will post some pics.

[Phoenix]

Thanks Phoenix, I need to think of an Idea to bend the pipe, Since I dont know anyone with a mandrel Bender. When Im done I will post some pics.

I got my local muffler to bend a steel intake pipe for me. I think he charged me ten bucks or something and the work is excellent quality. For mig/tig welding in the vacuum ports a local industrial machine shop will probably do it for next to nothing. Take lots of pics. I want to see how it turns out. I'm fixin to do the same thing at some stage.

[batmobile]

Hey Thanks for that info, I know of a local muffler shop near here. I will drill some holes and get some small aluminum pipe for those 2 air things. I have a Tig welder so i guess I will attempt it.

[Junkie]

READ-----Maximum Boost..........Corky Bell.

Steel pipe is better than aluminum.Aluminum will retain the heat,dissapate less than stell.

I was under the same impression as you,until I did a bit more research.

[Phoenix]

Does that mean that steel would be a better material than aluminum to make the plenum and runners out of not to mention a cylinder head?

[batmobile]

Im going to have to dissagree with you junkie. You are dead wrong. All of the high end major manuafacturers of intake pipes prefer aluminum to steel constructions. Why:

1 They are lighter weight

2 They dissipate heat faster, Intake Internal heat dissapears because of the cold air constantly being sucked into the pipe which cools the pipe better than steel.

3 They look better than steel all polished up

Reasons to go with steel

1 Cheap to make

2 Easier to bend

3 Cheaper than Aluminum for materials

The only better route than steel and aluminum would to go with carbon fiber.

[Junkie]

Cylinder head tech is way betond heat and simple airflow.

As for the intake.......Hmmmmmmm....What do the Pro-Stockers use.....Custom sheetmetal,hand fabbed units.

Like I said..............................READ and learn.

I definately don't know everything,and even less about thermodynamics.Probably less than probably many on this board.But I do know how to look for info,and read.

[batmobile]

The only pro stockers who use sheet metal are the ones who loose and cant afford aluminum parts. Its hard to weld for one thing. And most dragsters I have seen Use carbon fiber which goes on the same basic principles of thermodynamics as aluminum.

[Junkie]

What ever,guess I'm tooooo old and out of the game for too long.

I still say read,and then read some more.







I'll go back to my little hole in the wall,and stay away from your thread now.

[batmobile]

So I guess I win, LOL Im just kidding Junkie, Either way Im sure its not going to make much of a difference. The thread was started because I wanted to know what material the RC intake pipe was and i found out it was steel. Anyways, Im going to have the pipe bent and I will post pics. I will tell you if there are any major increases in HP etc. Thanks for your input Junkie and Phoenix.

[BillyM]

Bat, throw up some real numbers when you speak of thermo-flow characteristics. I want you to do some research and give me definate percentages or figures.

A - Thermo-resistance % between aluminumized steel and aluminum.
B - Temp % increase between the AFM and the TB
C - HP loss % due to temp differences between the two pipes

When you come back with that, or even some of it, I think alot more of us will listen to your (currently) un-backed bullshitting. Until then, kindly show some of our knowlegeable members some respect and shut the fuck up when they give you good advice.

...all in my opinion ofcourse.

--BillyM
*edit*
I see you thanked him for his input, one step in the right direction
*edit*

[Tanya]

I'll have to agree with the others on this one.
I feel more constructive time should be spent on keeping the hot air away from the pipe (header wrap, heat shields etc.) but that's just me.

Good luck in your project

[batmobile]

Hot , The only reason Im building the pipe is because i dont wanna drop 190 on a ceramic coated one. After a while i will make a mold for a carbon fiber one, and Will make it out of CF which i know is better than steel.

For now I am not agreeing or disagreeing with anyone, Anyone with more posts obviously spends more time on this website than me and deserves the respect "COUGH" HOT M16 "COUGH" Junkie.

Personally I dont give a F*ck what the thermodynamic numbers prove. It all matters what happens on the Dyno.

[batmobile]

Thanks tanya!

[Phoenix]

Hey junkie, it's just not practical for me to run out right now to buy a book and read it. Since you obviously have the book why don't you just quote from it and give us a reason why you think you're right. I really would like to hear it. 8) In any case is there a cheap kind of ceramic that you can work with. There's gotta be some ceramic piping out there for some mundane use. :?

In any case I agree with Tanya about the exhaust manifold. That's definately the priority. But if you're about to make a new intake pipe for whatever reason you might as well get the best affordable material.

[supramantt10]

Hey junkie, it's just not practical for me to run out right now to buy a book and read it.
errr . . . :wtf1: . . . I thought that was how you gain knowledge? Correct me if I'm wrong. How is this not practical? Can you not read? Or are you simply stating that you are too lazy to read? I'm confused . . please enlighten us.

-Keith

**And if you were being sarcastic make it more obvious, b/c I just took it as rude**

[batmobile]

Its obvious the old people still go buy books, For us younger generation we can just search the web and find our answers. BTW I searched online and All the major high end companies make them out of aluminum. COugh AEM Cough

[Phoenix]

Hey junkie, it's just not practical for me to run out right now to buy a book and read it.
errr . . . :wtf1: . . . I thought that was how you gain knowledge? Correct me if I'm wrong. How is this not practical? Can you not read? Or are you simply stating that you are too lazy to read? I'm confused . . please enlighten us.

-Keith

**And if you were being sarcastic make it more obvious, b/c I just took it as rude**

That's either hilarious or really dumb, maybe both. It's eleven O'clock here and there is not bookstore open anywhere near. Also, last time I checked amazon.com isn't offering instant delivery yet. And even if I had the book right now it would take me a while to find the part that deals with this issue. I really do want to find the answer to this question. Junkie obviously has the book so he could just quote the relevent part dealing with this issue. Instead he is just repeating "read the book". I want to read. So how about it junky can you give us a quote? I'm more interested in learning than defending a position.

[Junkie]

Quick look and I may be quoting the wrong book,but I DO KNOW what I have read.If aluminum piping was better,I would have it installed on Ophir's car....trust me.

Arguments like this,are why I usualy don't attempt to help here much anymore.I don't answer many questions,ask even less.....because I read or as you young punks....search the web.

As for top of the line producers,HKS uses steel pipe,I have MOST of an HKS mkIII hard pipe set in my shop.

As for respect,it's not the post count,it's the combined years of experience,with more than just Supras,.

How many old school muscle cars have you owned ? I can'r count the 65-75 Domestics I have had,most were much faster than 90% of the mkii's or mkiii's on the road.


How many Supras have you even worked on,let alone converted to 7mgte? I have lost count of the total # of Supras.I have had my hands on no less than 14 7mgte conversions,in one way or another.6 have been built from start to finish in my shop.1 more to build there,and 1 more to wire up......and I'm done :!:

[Phoenix]

Quick look and I may be quoting the wrong book,but I DO KNOW what I have read.If aluminum piping was better,I would have it installed on Ophir's car....trust me.

Arguments like this,are why I usualy don't attempt to help here much anymore.I don't answer many questions,ask even less.....because I read or as you young punks....search the web.

As for top of the line producers,HKS uses steel pipe,I have MOST of an HKS mkIII hard pipe set in my shop.

As for respect,it's not the post count,it's the combined years of experience,with more than just Supras,.

How many old school muscle cars have you owned ? I can'r count the 65-75 Domestics I have had,most were much faster than 90% of the mkii's or mkiii's on the road.


How many Supras have you even worked on,let alone converted to 7mgte? I have lost count of the total # of Supras.I have had my hands on no less than 14 7mgte conversions,in one way or another.6 have been built from start to finish in my shop.1 more to build there,and 1 more to wire up......and I'm done :!:

What do you mean that might be the wrong book????Is that like admitting you were bluffing? In any case this really isn't a big issue. I'm sure both would make a pretty good intake. I like my steel pipe but I would like to know for sure which of the two is better before I make one that goes the whole way. I have no problem admitting when I'm wrong. That's sort of how learning happens I believe. I'd like to hear some reasons why you think steel is better. No one is questioning your experience. But if you "experienced" the difference between a car running steel or aluminum intake pipe I'd be surprized.

BTW you have a pretty hefty post count yourself. 8)

[spamalope]

Aluminum will disapate heat better and faster, bottem line. Why do you think you can run much higher compresion on an aluminum head then a cast iron head without detonation and all of that mess. This is due to the better heat dissapasion that the aluminum head has to offer. In my '65 barracuda project I have sitting in my driveway (as ussual) I'm running 10.5:1 on a iron head and even with quench and a cam that's set for that ratio it's hard to keep it happy on pump 91+ where the same with an aluminum head would be more then happy, infact with the cam I could go almost 11.5:1 without to much dramma. I know that these are apples to oranges with this example but im just making a point about that aluminum will disapate heat real well, better then steel.

Basicly on a stock/near stock 5/6m motor the hp gain that you would get from it would be near non-existant I would imagine. Makes sence to sell a steel pipe that makes basicly the same hp gain over stock and have people be able to afford it. Just my 2 cents.

[Ross]

Gee you guys go off on a tangent.
Comparing alum heads to iron.
I mean, we have alum heads.
I doubt you could even measure the difference in hp on a dyno (btw, dynos don't measure hp)
I don't believe alum is better, but it's a little lighter and polishes up nicely, which is why I will probably make my next set from alum instead of the steel I am now using.

[BillyM]

Personally I dont give a F*ck what the thermodynamic numbers prove. It all matters what happens on the Dyno.

...because I am sure the two aren't related...

--BillyM

[StanS]

Where does the air entering your intake come from? Is it the cool outside air that just got heated up as it passed thru your radiator? So heated air enters your rc like intake. There has to be a temperature difference for heat to flow thru the intake pipe wall. What difference does it make what pipe you use since the air inside the intake pipe is nominally at the same temp as the air outside the intake pipe except for the spot where the intake pipe crosses over the exhaust manifold heat shield? Some insulation over that section of the pipe will eliminate any heat flow thru the intake pipe wall. Here's some rough relative coefficients of thermal conduction (heat flow). The higher the number the faster heat flows. copper 1400, aluminum 1000, steel 500, stainless 100, plastic 1-3, 1" fibreglass or foam 0.1. Steel conducts heat 5000 times faster than insulation and Aluminum 10,000 times faster. It's obvious that a bit of insulation is far more effective than the choice of steel or Aluminum. Note that plastic doesn't conduct much heat either and that's what toy used since the stock intake is above the radiator where the air is still at or near outside air temp and toy was concerned about heat flow thru the intake pipe wall. Using an open air KN filter under the hood isn't very effective for power gain since you're throwing away a lot of the power gain you get from increased airflo by using less dense heated air. Cold air intake with insulated mandrel bent intake piping is the way to go if your serious about power gain. (Under fender air is about 15 deg F hotter than
outside air at speed so under fender is not the best place to take your air from.)

[Junkie]

What do you mean that might be the wrong book????Is that like admitting you were bluffing?




F#@$ off !!!! Phoenix.I know what I have read,I'm not a young punk just trying to throw shit out there.Just because it isn't in the book I thought it was in,doesn't mean shit.

Build it your way,probably doesn't make that big of deal.Just trying to help,and getting a blast of shit will just make sure I don't even try to help again.

See ya

[Phoenix]

What do you mean that might be the wrong book????Is that like admitting you were bluffing?




F#@$ off !!!! Phoenix.I know what I have read,I'm not a young punk just trying to throw shit out there.Just because it isn't in the book I thought it was in,doesn't mean shit.

Build it your way,probably doesn't make that big of deal.Just trying to help,and getting a blast of shit will just make sure I don't even try to help again.

See ya

I think the only one "blasting $hit" here is you Junkie. :D Everyone else has managed to discuss this matter without losing their cool. Perhaps a chill pill or some anger management is in order. LOL :lol: I hope you're feeling better today.

[Phoenix]

Where does the air entering your intake come from? Is it the cool outside air that just got heated up as it passed thru your radiator? So heated air enters your rc like intake. There has to be a temperature difference for heat to flow thru the intake pipe wall. What difference does it make what pipe you use since the air inside the intake pipe is nominally at the same temp as the air outside the intake pipe except for the spot where the intake pipe crosses over the exhaust manifold heat shield? Some insulation over that section of the pipe will eliminate any heat flow thru the intake pipe wall. Here's some rough relative coefficients of thermal conduction (heat flow). The higher the number the faster heat flows. copper 1400, aluminum 1000, steel 500, stainless 100, plastic 1-3, 1" fibreglass or foam 0.1. Steel conducts heat 5000 times faster than insulation and Aluminum 10,000 times faster. It's obvious that a bit of insulation is far more effective than the choice of steel or Aluminum. Note that plastic doesn't conduct much heat either and that's what toy used since the stock intake is above the radiator where the air is still at or near outside air temp and toy was concerned about heat flow thru the intake pipe wall. Using an open air KN filter under the hood isn't very effective for power gain since you're throwing away a lot of the power gain you get from increased airflo by using less dense heated air. Cold air intake with insulated mandrel bent intake piping is the way to go if your serious about power gain. (Under fender air is about 15 deg F hotter than
outside air at speed so under fender is not the best place to take your air from.)

Great info Stan. Thanks. 8)

[Dean]

Some of you guys go on about aluminum dissipating heat better, but you've only got half the story.

Think about it....
Aluminum conducts heat 2 times better than steel and 10 times better than stainless steel. That's a fact, thanks for the numbers Stan.

You want your intake air to be cold. Thermal energy can only be transferred from a hot object to a cool object. Your engine is hot (certainly hotter than the intake air), and heat is radiated/conducted/convected to the intake piping, making it hotter than the intake air. Do you think that heat will magically be "dissipated" to the hot surrounding air? Or do you suppose it will be "dissipated" to the cooler air running through the inside of the intake pipe?
So as you can see, you want a non-conductive intake pipe.

Junkie knows what he's talking about.....

[Phoenix]

OK, since stainless and aluminum differ by only a factor of two while both are five orders of magnitude away from an insulating material, I think its time to move the discussion on to how best to insulate the pipe.

Rubber paint or insulating tape seem like they'd work but both would probably peel off and look excessively makeshift. I've seen pictures of pipes with a sort of silver colored insulating jacket. Where can you get that stuff and roughly what does it cost? :?

[Dean]

OK, since stainless and aluminum differ by only a factor of two while both are five orders of magnitude away from an insulating material, I think its time to move the discussion on to how best to insulate the pipe.

They differ by a factor of 10 which is significant. Read carefully.

If you want the bling factor as well as fairly low heat transfer, polished stainless would be a nice choice. That's what I've used to replace my intake resonator.

If you want the lowest heat transfer possible, then wrap it with insulation. Wrapping the headers also helps. Bling factor goes down, performance goes up!! My race car has wrapped headers and wrapped intake pipe as it is all go and no show.

[Phoenix]

OK, since stainless and aluminum differ by only a factor of two while both are five orders of magnitude away from an insulating material, I think its time to move the discussion on to how best to insulate the pipe.

They differ by a factor of 10 which is significant. Read carefully.

If you want the bling factor as well as fairly low heat transfer, polished stainless would be a nice choice. That's what I've used to replace my intake resonator.

If you want the lowest heat transfer possible, then wrap it with insulation. Wrapping the headers also helps. Bling factor goes down, performance goes up!! My race car has wrapped headers and wrapped intake pipe as it is all go and no show.

Oh I based that on the aluminum being 10000 times faster than insulation while steel is 5000 times faster. That's a factor of two.

My point is that they're both way closer to each other than either is from insulation. With insulation the difference in core metal would become pretty small. But you're right, that doesn't jibe with the other numbers, I stand corrected. 8)

I've see one of those polished metal pipes in place of the baffler. It does look pretty cool. Polishing would definately reduce heat pickup a little bit.
I'm going to wrap my manifold with insulation tape. But I'd like something that looks a bit better for the intake. I guess I want mostly go but some show. This car is my one and only. :D

[Tanya]

as pertaining to some silly comments made earlier, post counts have nothing to do with knowledge. PERIOD.
I'm like the #2 poster on this forum, and I KNOW JACK $H*t.
I've only been into these cars since March, 2001...so a little over 3 years now....and it's been a slow time learning. You learn from your mistakes, and I've made plenty so far. But I'm no where near as knowledgeable as some of the others.

Please disregard post count as equalling smarts.
:?

[Phoenix]

as pertaining to some silly comments made earlier, post counts have nothing to do with knowledge. PERIOD.
I'm like the #2 poster on this forum, and I KNOW JACK $H*t.
I've only been into these cars since March, 2001...so a little over 3 years now....and it's been a slow time learning. You learn from your mistakes, and I've made plenty so far. But I'm no where near as knowledgeable as some of the others.

Please disregard post count as equalling smarts.
:?

Yeah I'll second that. I'm definately a novice. The knowledge of some people here astounds me. :shock: It's great to have experts around to answer really difficult questions. On the other hand I learn a $hit load of good stuff from other novices who post a lot. It's like they're going through the same learning curve, discovering things that many of the experts don't even remember having to learn. Explainations are always necessary though. Whithout them you just can't extend your knowledge base. And really there is no need to get heated about any of this stuff. We do this stuff to our cars for fun, after all.

:dj_smile: :twocents: :fruit:

[canadian_psyko]

Post count may not show knowledge, but I think it does show a measure of devotion to the cars we love.

I think someone said this already (Wes?) but I'm pretty sure getting air from outside the engine bay would be more useful than insulation or various grades of metal.
I don't know about all of your cars, but I know my engine bay gets hot enough I can't touch the hood anymore. Maybe I should intercool my n/a 8)

What about just a pvc pipe with silver paint?


Cam

[SupraFiend]

thats crazy talk :P


Dean, thanks. I only read to the end of this thread to see if I had to mention your point about why you don't want an intake pipe material that conducts well. At least someone got it.

[batmobile]

Ok, Everyone, I will admit that Im wrong about the whole aluminum thing, And since plastic is the best, I would asume that carbon fiber/Fiberglass is right up there with the rest. Im going to focus my efforts to a Ram air Fiberglass/or carbon fiber Intake pipe a little wider than the outside diameter of the AFM and the TB. I may have to relocate the AFM to accomplish this. Im also going to change the direction of the pipe, so it is no longer above the headers.

[Dangerous Ken]

Ok, Everyone, I will admit that Im wrong about the whole aluminum thing, And since plastic is the best, I would asume that carbon fiber/Fiberglass is right up there with the rest.

Never ASSUME.

Carbon is a pretty good conductor and certain types of strong glass fibers (S Glass) are pretty good conductors too.

Have you ever heard of a complaint of a Carbon Fiber shift knob being HOT...

There are fabrics, like ceramic based cloths that would be similar to plastic. And then you would have to qualify the 'matrix' that you cure your fabric in too.

Ken

[batmobile]

Here's some rough relative coefficients of thermal conduction (heat flow). The higher the number the faster heat flows. copper 1400, aluminum 1000, steel 500, stainless 100, plastic 1-3, 1" fibreglass or foam 0.1. Steel conducts heat 5000 times faster than insulation and Aluminum 10,000 times faster. It's obvious that a bit of insulation is far more effective than the choice of steel or Aluminum. Note that plastic doesn't conduct much heat either and that's what toy used since the stock intake is above the radiator where the air is still at or near outside air temp and toy was concerned about heat flow thru the intake pipe wall.)

Im not assuming anything, Its right here, Fiberglass of foam is .1. So its 50,000 times better than steel(give or take a few. So ideally you want a plastic, fiberglass, or CF intake pipe with no restrictions.

[StanS]

Jamie (Ghostrider) used a rc pipe and insulated it with foam enclosed in an aluminum pipe jacket as i remember (Please chime in here Jamie). This should give more than sufficient insulation for insignificant heat flow and looked nice as she described it. She also has a cold air intake. I would have done the same thing but I didn't want to give up the resonator which corrects a few hp drop from 2900-3400 rpm and reduces engine noise to some degree. I made a 3" dia plastic (pvc) thinwall (o.d. = 3.25") intake pipe which I wrapped in 1.5" thick aluminum coated fiberglass insulation. The fiberglass is there to prevent the pvc pipe from sagging due to heat soak on a hot day after the engine is shut off and the car is parked in the sun. I also made a resonator by cutting out a 3.25" hole in the stock resonator and passing the pvc pipe thru the resonator chamber. (I made the existing pipe in the resonator wider). I cut a ~1/16" wide slot in the pvc pipe in the center of the resonator chamber. (actually, i cut 2 almost 1/2 slots so the 2 lengthwise (same as flow direction) halves of the pvc pipe passing thru the resonator are connected by two ~1/8" connecting bridges). I made sure that the distance from the tb to the slot was the same as stock so i didn't change any resonant tuning rpm. I measured and reproduced the stock slot width so 1/16" is approximate because I don' remember the exact width. I tried running the intake pipe with and without a slot (resonator). There may have been a barely detectable power gain between 2900-3400 rpm with the resonater but there was definitely a big reduction in noise.
Also, I wrapped the afm in fiberglass which is very easy to do and got a little gain (i have cold/ramair setup http://autos.groups.yahoo.com/group/mk2/files/Ramair%20instructions/ and http://autos.groups.yahoo.com/group/mk2/files/Air%20Box%20to%20AFM%20coupling/ which I've posted 7 zillion times)

[StanS]

I posted the relative heat conduction rates from memory this morning. Just looked them up. They're a little different but the conclusions are still the same. Copper 2610, Aluminum 1450, Steel 290, Stainless 112, plastic 1-3.5 fiberglass 0.05

[batmobile]

hey stan , I cant access the photos, But im very interested to see what you have done. Email the pics to Justaddwadda@aol.com, or post them directly.

[StanS]

i just accessed photos. join e-groups and look thru files. there's lots of other good info there.

[TEMPEST]

I don't really get it? why the big deal? This is what I understand. Using an intake of aluminum will heat the air inside much faster than a steel one. The surrounding engine bay air is hot. Aluminum dissipates heat much more efficiently than steel, but since it is in a hot environment, heat cannot be dissapated. Think of this...A steel pan on the stove takes longer to heat up than an aluminum one. But once hot is great for cooking. An aluminum pan takes less time to heat but will cool lots faster as heat is removed.
I hate cooking on aluminum, I digress, What I guess I mean to say is, I'll stick with steel until someone makes one of ABS. Perhaps I will. As far as wrapping in insulation, great idea for keeping heat out. Unfortunately..also great for keeping heat in, it will prematurely destroy a header. The part will heat stress corrosiode and fail. I would also stay away from carbon exhausts. They give off DEADLY toxins as they burn. It is considered a class 4 fire. The heat generated by your motor will cause it to give off fumes. Either way the entire idea of a "cold air intake" is a misnomer. I'm happy with the unrestricted flow achieved with the rc intake.


TEMPEST

[batmobile]

i think cowl induction on my hood should help with engine bay heat dissipation. especially if placed right above the headers.

[StanS]

Tempest
You're correct. If u use the underhood hot air as your input it doesn't make any difference what kind of pipe u use except where the intake passes over the exhaust mani heat shield (or near your header if u have one). U need a temperature differnce to pass heat thru the intake walls. Since the intake air inside the intake pipe is at the same temp as the engine air outside and surrounding the intake pipe there is no temp difference across the intake pipe walls and no heat will flow thru the intake pipe walls and the air flowing thru the inside of the intake pipe will not get heated up to a higher temp. (Obvious physics which some peeps ignore. Heat flows from a higher temp object to a lower temp opbject. When an object absorbs heat it's temp rises proportional to the amount of heat it absorbs. i.e. The more heat the object absorbs, the higher it's temp rises. Heat flows thru materials (like water thru a hose). Every material has a heat conduction rate associated with it (called coefficient of thermal conduction). The higher the coefficient the faster heat flows thru that material (hose has bigger diameter).

To complicate matters heated objects (such as heat shields and headers)radiate energy. When this radiant energy hits a surface (intake pipe walls), part of the energy reflected (like visible light gets reflected) and part of the energy gets absorbed and turns to heat (and flows thru the intake walls and heats the air traveling thru the inside the of the pipe. The air inside the pipe is cooling the pipe walls by absorbing heat from the pipe walls). The rc pipe which is ceramic coated should be an excellent radiant heat reflector but, I assume (since no one will tell me the coefficient), has a fairly high conduction coefficient. But as i just said, conduction doesn't make a difference since the air inside the intake is already at the same temp as the air outside the intake pipe.

If u port ambient temp air ("cold air") from outside the engine compartment thru the intake pipe then the air inside the intake pipe is cooler (and denser) than the engine air surrounding the intake pipe and obviously u want to use low thermally conducting pipe or insulation around the intake pipe to prevent heat from flowing thru the intake pipe walls and heating the air flowing thru the inside of the intake pipe.