Topic: Phenolic Spacer Discussion (split from Parts Pictures)

[snackers]

Oh hey look... Phenolic Spacers from KS Tech

I've been trying to figure out what these will do for a turbo engine but rs25 is full of ricers and that's the only place I've looked because I'm lazy.
Wanna CN it for me in 20 words or less?

[Zaider]

I've been trying to figure out what these will do for a turbo engine but rs25 is full of ricers and that's the only place I've looked because I'm lazy.
Wanna CN it for me in 20 words or less?

Your intake manifold gets hot because its directly connected to the block. This isolates it and should lower Intake Air..... Temperature.



I haven't seen any definitive testing however I was able to find a guy who did some tests and found that a before/after test showed his IAT's were 30 degrees lower while cruising at 60mph with the phenolic spacers installed. Basically the block is a giant heat sink and makes your Intake Manifold really hot. This is supposed to help.

To be honest, the only reason im installing them is that the Intake Manifold needs to be removed to fix my fuel lines. Its the same reason I am replacing my Turbo Inlet... cause its convenient to do it all at the same time.

[snackers]

Your intake manifold gets hot because its directly connected to the block. This isolates it and should lower Intake Air..... Temperature.

Yeah, that much I got.

But when you're in boost, how much heat will the air really take when it's traveling at that speed?

[Zaider]

Yeah, that much I got.

But when you're in boost, how much heat will the air really take when it's traveling at that speed?

http://autospeed.com/cms/A_110474/article.html

this is about the calibre of data that I can find...

[AdamMc]

Because the 08+ Intake manifolds are plastic: do they essentially achieve what you're trying to do with the separation of the intake manifold from the block? 

So the point I'm getting at: is something like this worth while on an 08+ application?

[jer]

Because the 08+ Intake manifolds are plastic: do they essentially achieve what you're trying to do with the separation of the intake manifold from the block? 

So the point I'm getting at: is something like this worth while on an 08+ application?

IIRC that was part of the reason they went to the plastic manifold?

[snackers]

IIRC that was part of the reason they went to the plastic manifold?

That was my understanding, except that the STI didn't get the same treatment.

My question was more in general for turbo cars specifically.
The NA crowd over on rs25 swears they pull mad tyte powers, but I don't know how long the air stays in the IM, especially while under boost.
Is it long enough to really grab that much heat from it?

[Zaider]

That was my understanding, except that the STI didn't get the same treatment.

My question was more in general for turbo cars specifically.
The NA crowd over on rs25 swears they pull mad tyte powers, but I don't know how long the air stays in the IM, especially while under boost.
Is it long enough to really grab that much heat from it?

That's a good point. Here's my theory based on what I remember from my 3rd year thermal and fluid mechanics clases. The interior of the intake manifold is not coated with anything at all, so I would assume that it is quite condusive to heat transfer. The air running along the outside of the "air mass", along the walls of the IM is going to be conducting that heat (air is not a good conductor of heat to begin with). The fact that the air is under pressure is "forcing" it against the walls even more therefore, at any given time, there are more air molecules touching the IM surface and gaining heat. It is a turbulent flow (as opposed to laminar) meaning more molecules of air are coming in contact with the surface of the IM over the period of time that the "air mass" is in the IM. Therefore, my theory (that im just thinking up right now) is that even though the flow rate through the IM is higher, the number of molecules in contact with the IM is also increased.

Here's a good site that explains the mechanics of heat transfer: http://www.engineeringtoolbox.com/overall-heat-transfer-coefficient-d_434.html

Im pretty busy at work so I can't check my theory with hard numbers... but... our IM's are aluminum right? The thermal conductivity is extremely high: Aluminum - 221 W/mK

[snackers]

That all sounds good to me.
I didn't think about that, but it makes sense.
Forcing the air through faster means it might spend more time hugging the wall.

[Zaider]

That all sounds good to me.
I didn't think about that, but it makes sense.
Forcing the air through faster means it might spend more time hugging the wall.

Its really only a theory... and it could definitely have flaws so dont bet the bank. I wouldn't just choose to install one... but... based on the fact that:
a) They are cheap
b) The IM is coming off anyway
c) The theory seems sound to me and I have seen some "data" to support it

I figured why not? I went with the thinest one though because going thicker apparently gives TMIC and IM fitment issues sometimes.

[Hurricane]

That's a good point. Here's my theory based on what I remember from my 3rd year thermal and fluid mechanics clases. The interior of the intake manifold is not coated with anything at all, so I would assume that it is quite condusive to heat transfer. The air running along the outside of the "air mass", along the walls of the IM is going to be conducting that heat (air is not a good conductor of heat to begin with). The fact that the air is under pressure is "forcing" it against the walls even more therefore, at any given time, there are more air molecules touching the IM surface and gaining heat. It is a turbulent flow (as opposed to laminar) meaning more molecules of air are coming in contact with the surface of the IM over the period of time that the "air mass" is in the IM. Therefore, my theory (that im just thinking up right now) is that even though the flow rate through the IM is higher, the number of molecules in contact with the IM is also increased.

Here's a good site that explains the mechanics of heat transfer: http://www.engineeringtoolbox.com/overall-heat-transfer-coefficient-d_434.html

Im pretty busy at work so I can't check my theory with hard numbers... but... our IM's are aluminum right? The thermal conductivity is extremely high: Aluminum - 221 W/mK

This is one of the reasons I decided against going with the hard inlet ... another place for heat to be transferred to the intake charge.  The other reason is the number of horrible fitment stories.

[Zaider]

This is one of the reasons I decided against going with the hard inlet ... another place for heat to be transferred to the intake charge.  The other reason is the number of horrible fitment stories.

I wonder how tight the fitment will be with the extra 3mm clearance from the spacers.

If, when I do the install, I can afford to have my car down for a couple days, I might test fit the hard inlet and see if there is room to wrap the turbo inlet in as thin a layer of exhaust wrap that I can. We'll see though...

[Way-do]

How much surface area is inside your intercooler?
We all go to great lengths to keep that thing cool, and while obviously, it sheds energy much more effectively due to surface area and alloying, the air charge is howling through there just as fast, and thermal conductivity doesn't much care which direction it is going.

Flow velocity at the wall is much lower, so it has more contact time as well.  Throw in the turbulent flow so it mixes into the main flow better.

The biggest gain is keeping the IM from heat soaking to begin with. All that heat goes into the radiator... and is then blown back over the engine.

If we keep using big engineering words, this may have to move to technical discussions.

[Zaider]

If we keep using big engineering words, this may have to move to technical discussions.

Done.

Rumour is that you can touch your IM after installing these. Now, i dont know about you, but mine gets really hot from heat soak... so... if it helps a bit, its worth it.

Really, I dont even think that dyno testing would be any use in this case. The benefits would be mostly after the engine has been running for a while and the IM is heat soaked.

Before/After IAT's would be nice... maybe ill look into that

[Airboy]

Your intake manifold gets hot because its directly connected to the block. This isolates it and should lower Intake Air..... Temperature.



I haven't seen any definitive testing however I was able to find a guy who did some tests and found that a before/after test showed his IAT's were 30 degrees lower while cruising at 60mph with the phenolic spacers installed. Basically the block is a giant heat sink and makes your Intake Manifold really hot. This is supposed to help.

To be honest, the only reason im installing them is that the Intake Manifold needs to be removed to fix my fuel lines. Its the same reason I am replacing my Turbo Inlet... cause its convenient to do it all at the same time.

The article that you linked says the IM was 30F cooler, not the IAT.  Unless I missed it somewhere...

[Zaider]

The article that you linked says the IM was 30F cooler, not the IAT.  Unless I missed it somewhere...

Oops. You're right. I misread that.

[Zac]

installed these on my old ej22 NA and I swear by them.

Yes you can touch your IM after a long hard drive, I then proceded to touch my block and burnt my finger tip.

But like most said my 05 LGT has a plastic IM so I will not be installing them this time around.

Zaider you dont need to remove your whole intake manifold to put them on, just unbolt it, pry it up and slide them under

I had to remove my power steering line bracket on my old legacy to get a little extra clearance.

[edicius]

He bought them because he was going to take the intake off to do his fuel rails and figured why not since i'm in there.

Hope you bought enough intake gaskets Zev.

[Zaider]

He bought them because he was going to take the intake off to do his fuel rails and figured why not since i'm in there.

Hope you bought enough intake gaskets Zev.

Exactly..

umm.. four? I think that's how many I need....

Im waiting until January 17ish before I do this...

[funk32]

ya you need 4, I have a set of 8mm phenolic spacers from GS. I got them for uber cheap so I said why not while doing a rebuild, plus it gives more room for th aps 3" turbo inlet. I will also be going to a FMIC so I wont have fitment issuses with a tmic.

[edicius]

Will you be doing this in a newly acquired garage?

[Zaider]

Will you be doing this in a newly acquired garage?

I will

probably first thing... before even moving in.

[edicius]

Awesome good to hear, if you need a hand let me know.

[Sleeper]

I heard of a few of them cracking at low temps, ie. our climate... might be something to confirm or not. Rocket wouldn't let me install them on my car for that reason when it was still winter driven. Maybe the spacers have changed since then (3 years ago).

[Way-do]

I have a hard time believing that phenolic would crack.  It is realy, amazingly tough stuff and for an engine to contract that much in the cold, assuming thermal expansion is linear wrt to T, -30 to 0 (cold Engine vs REALLY cold engine) is nothing compared to 0 - +95. (cold engine vs hot). Cold to hot is 3 times the expansion and I have NO IDEA what the coefficient of expansion of Phenolic is but I seem to recall it is colse to aluminum.

DeltaL = L1 *(CoEff of Exp * DeltaT)