Can I ask... does it seem reasonable to you experts... that an intercooler would perfom so well that your intake temps at the manifold are only a couple degrees fahrenheight over ambient?

 

talkin' to me?

 

Yeah sure.. anyone. I'm just wondering what performance to expect out of various intercoolers. I sort of thought about 20c above ambient was good. Then that madman Buschur came along and spoiled my day and says his race core only adds a couple degrees F over ambient.

So now I am like... does my intercooler suck... or not?

 

It just seems to me... you have air flowing into the turbo compressor housing. The housing and wheel is presumably pretty darn hot. Then you have the air being pressurized as well which I think adds heat too?

Then this air which is now presumably considerably hotter than ambient.. is flowing through an intercooler which is not considerably cooler than ambient. So I'd think it is easier for the compressor housing of turbo to add heat to the charge versus the intercooler to pull heat from the charge because the delta from ambient is much larger with the turbo.

So my braindead assumption is that it is very hard for an intercooler to bring things back to a point which is very close to ambient.

 

when moisture condenses on your cold ice filled coke cola glass it does so because of the cold temperature inside the glass,,, when it evaporates back into the atmosphere it will only do so after the glass has warmed up to ambient conditions, or the little droplet of water rolls down the glass and rests on the table beneath it,,, which i would bet, is room temp... think about it....how much energy does it take for the water to condense on the glass and how much does it take for it to vaporize again????

Fog? yep i heard of it... super saturated air,, fog is visible because it air as reached 100% relative humidity. Which is where , i assume you get your Pressure idea from above. although you did not apply it correctly.... relative humidity is the ratio of the partial pressure of vapor in the gas / air mixture divided by the saturation vapor pressure at a given temperature of water...
the key here is it is a ratio,, of the moisture in the air and the moisture that _could_ be in the air at a given temp ( in easier terms).. what does this have to do with anything stated above? nothing...

the key to all this intercooler bantering is as simple as an energy balance. ( regardless of steady state or transient conditions.. or compressible flow..) the heat, that can be removed from one fluid, _MUST_ be equal to the energy that is added to the other..

If you think about this, IT IS IMPOSSIBLE TO GET TEMPS EXITING AN INTERCOOLER, LOWER THAN THE TEMPERATURE OF THE OTHER COOLING FLUID.

the only way to do so, is if the water being sprayed on the intercooler is colder than the ambient air temp... if so, yes the exit temp of the air within the intercooler might be colder than ambient temps, but it will never be colder than the temp of water sprayed on the intercooler.


If an intercooler is capable of lower temps beyond the cooling fluid's temps, then every law of thermodynamics has just been broken and the whole world will end..

and for someone else's question,, a very well designed air to air intercooler could very well have an exit temp near the ambient air temp.. it might be fricken huge,,, but it could be done....

 

Your statements are incorrect. Water does not have to be cold to lower the temp of the surface below ambient. In my experiment above the water was 96 degrees. Room temp was 78. As it evaporated, which took about 7 seconds, the surface of the probe dropped 6 degrees below ambient to 72 degrees temperature. This is nothing more than the latent heat of evaporation in action. It takes heat energy to chance water to a vapor. The heat energy is pulled from the surface. Very simple concept to grasp. Same as getting out of a pool and feeling cold. You feel cold because the water evapoartes from you skin and you skin temp drops.

In ohio with ambient temps at 60 it is very easy to keep temps just above ambient with a good intercooler. In florida where it is very hot it is a whole different ball game. Local here did some temp measurements on his t25 powered dsm. In 90 degree weather. He saw 210 degress on the stock side mount. (TB temp) switched to a starion front mount and saw 170 at TB. Then switched to a supra sidemount and saw 140. This is not a good example of good intercooler. But an example of what factory coolers thought to exceptable 15 years ago.

With a spearco 24 x 13 x 3.5 core on my yellow car. I saw as high as 170 intercooler out (350 out of turbo) in 95 degree weather. This was with a 35r and 33psi boost. The meth cooled the air down to 105, just 10 over ambient. Something an intercooler alone is not going to do in hotter weather.

 

But this doesn't explain how an intercooler can achieve outlet teps. lower than the air passing over it's surface.

 

simple example everyone knows about... pouring hot water on a frozen windshield gets you frozen windshield... pouring cold water gets you melted windshield.

another simple example that everyone is familiar with that negates claims earlier. open a coke bottle... what happens? you get fog inside the clean particle free bottle... don't have to condense on anything.

 

i think Buschur is just scare of this test because it will show that his intercooler suck ***. lol

 

Well Buschur uses a Garrett core, as far as I know, so you'de be saying Garrett cores suck ***.

Which is far from the truth...

 

If there is a signficant ∆P of the compressed air as it moves across the core of the intercooler, the reduction in air pressure will cause the air to cool. If the compressed air entering the intercooler was already near ambient temperature, then with a large ∆P (e.g. stock intercooler), then I think that this cause the outlet air temperature to drop below ambient.

 

let's be fair... the dyno test was close. but cast end tanks and cnc brackets and details like that attract an informed and detail oriented customer.

 

suscribed

 

umm.... did you know that soda is carbonated? that is not fog...

and the getting puit of the pool is nice,, but feeling cold does not actually mean that you are cold....

second... the latent heat of vaporization idea is great,, but please explain how you can transfer that idea to an intercooler.... yes the surface get cold, but do you think the same happens with an intercooler?? no it does not!

energy balance... energy balance... energy balance....energy balance...

have you completed your tests on the intercooler yet? do you have real recorded results under strictly controlled conditions?? mimicing the actual operational conditions of loads on the car??
let the resutls speak for them selves....

 

no... not at all... pv=nRT is a steady state condition in a fixed control volume.... none of this applies in an intercooler... which is not steady state, nor is the volume of air fixed.. air that enters one side leaves the other... it does not stay in the intercooler...

oh yeah, one more thing... about the latent heat of vaporization idea everyone has.... look at the amount of energy that is transfered in an intercooler to the amount of energy in your latent heat idea...... several orders of magnitude difference.. i.e. it is almost neglible...

if you want to spray water and make it work,,, spray it in the intake,,, not on the intercooler