Infinite pressure might be a bad thing


But really all I've said is I'd like to see the data and there hasn't really been any, except for TonyB's new info which I haven't had time to read. Which of course post dates my original question.
My questions were raised by a few things. One being that the OEM scoop was inefficient and that there is some "wall" of air created by the front fascia that made in inefficient. And that this new scoop somehow magically made that wall of air go away or overcame it with superior design.
There's also several comments about the opening of the scoop being a bit lacking and needing modification.

I'm sure it works as a handy improved bug ingestion device but hey, if it keeps them off the windshield then so much the better.

All that aside, I never said it didn't work. I'd just like to know how well.

 

this is gibberish. you need to study a little fluid mechanics and understand the difference between pressure and force and air speed. making the scoop bigger doesn't change the maximum pressure you can get from the air at a given speed. you won't have more and more pressure through the ic the bigger and bigger you make the scoop. if you put a 4 foot x 4 foot scoop on your hood, you won't force any more air through the ic than the pressure and the resistance of the ic allow (at a given speed).

whether the stock scoop is "too low" and isn't getting clean air is another question.

 

Not true at all. I know plenty about fluid mechanics . I'll grant your assumption that I could not know what I am talking about, but the fact is I've studied quite a bit of physics in my time . Trust me. The thing is:

1) The path of least resistance with the stock scoop is over the hood. It does not stick out enough to capture much laminar flow AT SPEED.
2) The VAST MAJORITY of fluid therefore flows over that path, not through the stock scoop.
3) With little-to-no [AGAIN trust me I know what I'm talking about!] impediment to flow directly over top of the scoop, air will not magically seek it out. In FACT, proportionally LESS will enter as speeds increase, because the air following a path over top will have increasingly much inertia. A larger fraction will flow over with increasing speed.
4) The only way to change 1-3 is to add an incentive for the air to divert. A scoop can do this in TWO important ways. First of all, the lip of a raised scoop poses an essentially infinitely higher resistance to movement over than the stock one [that does not divert much air because it does not impede laminar flow, as I said above]. Since the scoop doesn't move if anchored in the hood [ie, approaching infinite resistance in its vicinity, ie AIR DOES NOT FLOW through], it FORCES air to follow new paths of least resistance. Therefore, this hood scoop increases air pressure outside the scoop, pushing in. Secondly, the scoop alters the front aerodynamics of our cars. It ADDS resistance to airflow above, yes, but that just means 2 things at speed: 1, increased downforce and 2, by Bernoulli's principle, that the air flows even faster UNDER the car. Now, since air below the car now flows faster, this helps suck more air out of the ambient environment of the engine compartment [AIR sucked in the hood ostensibly travels down, under the car]. This LOWERS resistance to flow through the engine compartment. This INCREASES flow. P=flowxResistance, so the hood scoop helps two different ways!

Of course all with input are welcome. I would love to see it modeled. But, that is the pure THEORY. I am quite a fan of physics and know more than enough through my studies to argue the above.

 

I take it you do not understand how the MCS intercooler works. The thing sits right OVER the engine block. For air to flow through en mass would be prohibitive because there are many impediments around the head cover. Instead, and this is the precise problem with our IC's, the air flows almost exclusively OVER the IC. It cools by convection, just like wind does to our bodies when we sweat. The goal of the scoop is to increase flow over the metal vanes, not through them.

As an aside, this is also why, I would venture, there is such little difference in performance between the stock IC and larger ones. Air flow is not flowing uniformly over the area. This is also why front mount IC's offer much better dyno AND TRACK results. They move the vanes of the IC to a place [in front of the radiator] which offers much better conductance.

 

That's classic!

 

Glad you like! Just the facts, right?

 

I think an equally plausible theory is that the intercooler operates via reverse osmosis and serves as a proton exchange membrane.

Tell you what, tape over the entire underside of your IC and get back to me.

 

Sorry, I'm too busy to be bothered with it in all honesty. Gotta study about meaningful things like saving lives. Man it sucks to be a med student .

You're more than welcome to, though. I remain confident.

 

I'm glad your confident in your theory, but it:

A) Makes no sense

and

B) Has no evidence to support it

 

Well that settles it! I'm convinced.

 

This is very interesting. I've actually wondered how much of this cherished air gets directed down through, and out the bottom of the IC. Maybe this has never been the intent of the design (I awlays was under that assumption)... and maybe this thinking is flawed. But then if the design was to cool simply by exposure of the top surface of the IC, I would think that there is much to improve upon then...

Duct tape at the bottom of the IC could get messy, but something along those lines though would allow us to confirm this... Heck, if room below the IC is not sacred space, a couple of those sucking eRAM fans might really make a difference...

 

a) it is perfectly logical.
b) has no evidence to contradict it. you're more than welcome to prove me wrong. seriously.

BTW, I'm signed up on the BIM-COM site but have not seen any indication of ETA. I want some logging software . You've got it. No fair.

 

maybe we should go back and re-visit this bad boy :

 

Where, pray tell, does the fluid that is an integral part of evaporative cooling come from?

I'm sorry - I'm trying not to violate the rules of this site by being disrespectful. But to make such a statement as quoted above is indicitive that you have not the slightest clue regarding the theory or implementation of anything remotely related to fluidics.

 

Is that an aftermarket IC that goes up and almost touches the top of the IC opening? How does it get air in it? How is that better than stock? I angled my stock IC down in the front and up in the back. Used washers to do it. The air has an easier time entering the IC than before.

Bomboasy

 

evaporative cooling/convection does not presuppose that fluid is involved. air behaves essentially like a fluid, hence i liken it to a fluid.

 

So, if this is true, what purpose does the air diverter serve???

 

It's simple really. As ingsoc indicated, "For air to flow through en mass would be prohibitive because there are many impediments around the head cover. Instead, and this is the precise problem with our IC's, the air flows almost exclusively OVER the IC. It cools by evaporative cooling, just like wind does to our bodies when we sweat. The goal of the scoop is to increase flow over the metal vanes, not through them."

So, it doesn't matter that air can't pass through the Forge intercooler. All it needs to do is pass over it and the miracle of evaporation does the rest. :smile:

 

When it sweats, the body cools mostly by convection, not by evaporating sweat [in humid climates, when water cannot vaporize, you are still cooled, just not as much...] . I was referring to the convective aspects of the process, not the evaporative one.

Sorry for any confusion and if I misspoke/mislead in trying to use a simile.

 

Evaporative cooling is not at all the same as convection. Look it up.

Also, air does not "behave essentially like a fluid". Air IS a fluid (it is also a gas - the two are not mutually exclusive properties).

 

The stock air diverter forces some air through, but nowhere near most. Most passes right over.

 

I know very well. Read the few posts above. Sorry.

 

I'm intrigued by your theory. How does the air "pass over" the intercooler? The scoop has foam sealing around the IC. So, does the air enter the scoop, spend some quality time in there doing evaporative cooling, then exit back out the front?

 

The stock diverter does not fit flush with the under-hood structures. That is why alta made theirs: to fill the gap.

 

I just stuck my hand in the scoop. There is a U-shaped piece of foam (reverse osmosis foam perhaps?) that seals the hood to the intercooler cover. The air has no choice but to go through the intercooler or back out the scoop to the front of the car.