ETS TMIC question

[Mid_Life_Crisis]

I'm kind of glad that many recommend the 3.5 inch core...
Though, is there no doubt that the bigger core is less prone to heat soak (thats what PG told me)? Thats its better in a high heat enviornment than the smaller 3.25 core...? I would have figured, more material (metal), more chances for heat soak... (scratch)

I would think it would be the other way around. You are generating the same amount of heat regardless. A bigger core means more surface area for air to flow over and pull the heat out of the unit. In addition, the heat is spread out over a larger area, so there are less BTUs per inch of surface area.
The reason there may be no significant difference between 3.25 and 3.5 is because of what is called "the law of diminishing returns". Simply put, since the system is only generating so much heat, you only need so big an intercooler to dissipate that much heat. Anything bigger is just wasted cooling capacity. If you get too big (4.00 for example) you might see response starting to drop off due to things like lag time pressurizing the larger intercooler. I suspect that for lightly modded engines, the 3.25 will be fine, but for guys like Driver and Laloosh who want every bit of power they can squeeze out of their engines, they may need the extra capacity of the 3.5.

 

[jbiird317]

thanks for all the responses... i think its clear that the 3.5 is the way to go. To Chacon - I think the point that you were missing is that the clearance from the ducting doesnt make a difference because the ducting directs all of the air directly to the intercooler. I think you are thinking of air free flowing through the engine bay without the ducting directing the air. From your example (.5" vs 1" of clearance), i think the way our tmic works, the less clearance from the hood the better because it gives the air nowhere else to go but through the IC.

for me the issue with the powder coating is that you insulate the intercooler reducing its ability to dissipate heat. Makes no sense.(uhm)

yes, thats exactly what i was thinking

As for the color, it doesn't matter that its black since the color with regards to heat is only an issue when in direct sunlight, which is not the case for us.

Is that true? That kinda flies in the face of what i was thinking about color and energy absorption, whether its heat or direct light energy, i thought that darker colors would insulate that energy more. This is the principle behind heat soak of the intercooler, darker color would only enhance this principle. (someone correct me if im wrong, but thats what chemistry tells me)

 

[USAF_TRobertson]

Since everyone seems to agree the 3.5 is no more efficient than the 3.25 why not play it safe and just get the 3.25? This will prevent the possible cooling issue and possible fitment issue.

 

[SuperStretch18]

Is that true? That kinda flies in the face of what i was thinking about color and energy absorption, whether its heat or direct light energy, i thought that darker colors would insulate that energy more. This is the principle behind heat soak of the intercooler, darker color would only enhance this principle. (someone correct me if im wrong, but thats what chemistry tells me)

Dark colors transmit heat more effectively. That goes for both absorption and radiation. As long as the air going through the intercooler is cooler than the intake charge (which it better be) black should cool better. The only issue (which I'm not sure of) is whether the coating will form a sort of insulation. I did find the page below which explains why a black engine block helps prevent overheating pretty well. The same color theories apply here:

http://www.offroaders.com/tech/paint-it-black.htm

As a side note; almost every oil cooler that I have ever seen is powder coated black...

 

[jbiird317]

Dark colors transmit heat more effectively. That goes for both absorption and radiation.

good call, i guess i forgot that part! Although according to that article the net gain in energy would be greater still for a darker color.

 

[SwampAss]

I have a 3.25 and had no fitting issue at all in regard to it making contact with anything.

I have an upgraded rear mount too though. It works great. Much better than my FMIC on my 1.8T GTI.

 

[Mid_Life_Crisis]

Since everyone seems to agree the 3.5 is no more efficient than the 3.25 why not play it safe and just get the 3.25? This will prevent the possible cooling issue and possible fitment issue.

But everyone doesn't agree with this. There are members who swear that the 3.5 is better for our vehicles. As I stated earlier, I think it is a borderline issue, and it may come down to how much power you plan to try to get out of your car. It may be like the fuel pump issue. Stock, or nearly stock, you don't need it. Start pushing the envelope and the extra capacity is necessary.

 

[chacon101]

I have always wondered who the in hell would pay for the Autoexe one? SU has them for like $1225! Boooo.

 

[Mid_Life_Crisis]

I have always wondered who the in hell would pay for the Autoexe one? SU has them for like $1225! Boooo.

I think the Swedish bikini team comes out and installs it while you watch.

 

[SuperStretch18]

good call, i guess i forgot that part! Although according to that article the net gain in energy would be greater still for a darker color.

Good point. I hate thermal dynamics...

 

[jbiird317]

Good point. I hate thermal dynamics...

lol yeah thermo and differential equations were the reason I made the move from chemical engineering to just chemistry in college. discussions like this are interesting and def make me wanna figure out the answer, but damn, i cant imagine doing it every day...

 

[whooosh]

the unfortunate truth in dealing with a TMIC is >>> regardless of the core thickness and the design be it air to air or liquid to air...you will be dealing with heatsoak issues simply due to the loaction

core CFM, air duct this and that, inlet/outlet diameter...doesn't matter
the aluminum IC can't hide from the engine and turbo heat no matter what you do

 

[AutoXRacer]

I just ordered the 3.25" core... I spoke with another vendor and they also confirmed that the 3.5" core partially blocks airflow through the duct on the hood side...

 

[redspeed]

Ken from pg said that there is almost no performance difference between the sizes.

Posted by Captain KRM P5 on 12-11-2006
"there is virtually no performance difference we have assessed between the two sized cores, so from this point on all that is being offered is the 3 inch core."

http://www.mazdas247.com/forum/showthread.php?t=123654573&highlight=ets+tmic

Then on 7-12-2007:

Posted by Captain KRM P5 on 7-12-2007
"thats old news - they are selling three core sizes; the 3inch, the 3.25inch and the 3.5inch. originally it was only going to be 3.5 inch but we had rubbing issues on the ms6. then it was going to be no more 3.5 and just the 3.25 exclusively. we found that the 3.5 inch models do not have the same issues on the ms3 that they do on the ms6, with the exception of the shroud on the intercooler being too long initially for the ms3 (would tap the firewall). those issues have all since been worked through and now all three options are still available to people."

http://www.mazdas247.com/forum/showthread.php?t=123675778&highlight=ets+tmic&page=9

 

[Jays07MS3]

Dark colors transmit heat more effectively. That goes for both absorption and radiation. As long as the air going through the intercooler is cooler than the intake charge (which it better be) black should cool better. The only issue (which I'm not sure of) is whether the coating will form a sort of insulation. I did find the page below which explains why a black engine block helps prevent overheating pretty well. The same color theories apply here:

http://www.offroaders.com/tech/paint-it-black.htm

As a side note; almost every oil cooler that I have ever seen is powder coated black...

That doesn't make sense at all. The way they transfer heat is by conduction (direct contact) not radiative like the article mentions. Aluminum has great thermal conductivity, paint does not. Since the air is physically coming into contact with the fins of the intercooler, you want the highest thermal conductivity you can get so that as much heat is transferred (from the fins TO the air) as possible in the shortest amount of time. If you cover the fins with paint or powder coating, you just put a barrier of low thermal conductivity between the intercooler and the air. Less heat will now transfer from the fins to the air. Its simple physics.

This would be akin to painting heat sinks for electical components. Google "Painting Heat Sinks" and you'll see what most people think about it

Here's a good article about why it would be beneficial to anodize it but not paint it.

Is black better?
Recently, as part of our electronics course, we learned about the properties of heat sinks. The course notes (and exam mark schemes) claim that to make a heat sink more efficient it should be painted matte black.

I understand that this would make it more efficient, but my friend and I wondered why CPU heat sinks are not painted matte black? Most other heat sinks (attached to amplifiers etc) seem to be painted in this fashion, so why not CPU heat sinks?

Peter

Answer: Your course notes are right, and they're wrong.

A black object will, all things being equal, radiate heat better than one of any other colour. However, painting a shiny heat sink black may do nothing, or less than nothing, for its thermal performance, because the layer of paint acts as an insulator. The black colour must be an integral quality of the heat sink material, or a very thin, thermally conductive layer on the outside; black-anodised aluminium is a perfect example of a good black heat sink material. It's possible to put a useful thermal black patina on copper by putting it in a hot sodium hydroxide and sodium chloride solution bath (also useful for disposing of corpses), but that's neither a quick nor an easy process, so people usually only bother doing that for copper that's being used as a thermal absorber, as in solar water heaters, not on heat sinks.

This is because the colour of the heat sink matters less and less the more air you move over it. If the sink's hanging in vacuum (like the heat radiators on spacecraft that stop their own waste heat from boiling them) then it must be matte black; if it's sitting on earth being cooled by convection then it should be matte black; if it's got a bunch of forced air cooling from an attached fan then it doesn't matter a great deal what colour it is.

Again, all things being equal, a shiny aluminium heat sink with a fan on it won't work quite as well as a black one - but the difference will be small enough that the extra marketability of the shiny heat sink is likely to be the deciding factor.

A shiny fan-cooled copper heat sink, which can't easily be made black without pointless insulative paint, will work better than an aluminium one with the same dimensions, thanks to copper's rather higher thermal conductivity.

Under natural convection conditions, the performance of a heatsink with a black surface will be 6% to 8% better than that with a plain or bright surface. However, this differential disappears under forced air conditions.

Remember this a black surface that is not "painted" on. Its an extremely thin layer of anodize which gives it basically the same thermal conductivity as the underlying metal.

 

[SuperStretch18]

I was only referring to the color black which everyone was discussing, which is why I said:

...The only issue (which I'm not sure of) is whether the coating will form a sort of insulation...

 

[jbiird317]

Remember this a black surface that is not "painted" on. Its an extremely thin layer of anodize which gives it basically the same thermal conductivity as the underlying metal.

are you speaking of the powder coating here? or about the black annodized steel they were talking about in the article?

 

[redrocketz]

I just ordered the 3.25" core... I spoke with another vendor and they also confirmed that the 3.5" core partially blocks airflow through the duct on the hood side...

Just processed the order for ya

 

[Jays07MS3]

are you speaking of the powder coating here? or about the black annodized steel they were talking about in the article?

Anodized. And you can't anodize steel because of oxidation reasons. Just Aluminum and some other metals.

 

[SSMS3]

thanks man, thats exactly the info I was looking for. My basic physics/chemistry knowledge tells me that darker colors retain their heat more, so powdercoating didnt make sense, i guess I just needed to hear it from someone else too haha.

As for the 3.5" core, I know we started this discussion in another thread, but clearance of the hood ducting is ok with no trimming? Also, I see the PG website reccomends upgraded motor mounts if youre going with the 3.5" core for the ms6, have you noticed a need for the upgrade with yours?

opinions other than driver's are welcome too, haha

I had clearance issues with the firewall, but none with the hood ducting from my 3.5" core ETS