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Discussion Starter #1
Ok, so I'm going to be showing my n00b here. F*ck, I feel so stupid having to ask this question right now. But please don't be too harsh with me; I am a mechanical dunce.

So I'm trying to educate myself on the whole business of supercharger vs turbocharger. As well as trying to figure out what the best options are for preventing heatsoak to the S intercooler. I've had a great time learning about the various methods people have proposed to remedy or at least minimize or delay the situation. (water/methanol injection, a2w intercooler, shoco's DIY duct work.) However, I've come across something that kinda threw me for a loop that is related to the intake system but not necessarily the heatsoak issue.

Where does the supercharger suck the air from? I know it sucks in air from somewhere. Where along the "path of air" threw the engine path does it come in? The way I'm guessing (and I'm sure you'll tell me if I'm wrong) is this:

- Air comes in through an intake somewhere.
- Goes through an air filter.
- Gets squeezed through the supercharger.
- Compressed air is piped to the intercooler...
- Where the heated compressed air is cooled by the intercooler, which is being fed cold air via ANOTHER intake (this case, the roof scoop).
- Cooled, dense air is piped into the cylinder.
- Bang!
- Exhaust....

I guess my question is on a supercharged car are there actually two intakes? One for the supercharger that is filtered and one for the intercooler that is unfiltered?

I'm sorry if I'm just spouting nonsense trying to formulate a correct question to ask. Hopefully someone more knowledgeable can enlighten me.
 

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Where does the supercharger suck the air from? I know it sucks in air from somewhere. Where along the "path of air" threw the engine path does it come in? The way I'm guessing (and I'm sure you'll tell me if I'm wrong) is this:

- Air comes in through an intake somewhere.
- Goes through an air filter.
- Gets squeezed through the supercharger.
- Compressed air is piped to the intercooler...
- Where the heated compressed air is cooled by the intercooler, which is being fed cold air via ANOTHER intake (this case, the roof scoop).
- Cooled, dense air is piped into the cylinder.
- Bang!
- Exhaust....

I guess my question is on a supercharged car are there actually two intakes? One for the supercharger that is filtered and one for the intercooler that is unfiltered?

I'm sorry if I'm just spouting nonsense trying to formulate a correct question to ask. Hopefully someone more knowledgeable can enlighten me.
The intake for air that is mixed with fuel for combustion is behind the driver's side air vent/scoop. That's true for all factory Federal Elise/Exige models that I know of.

The intake for the intercooler (air used to cool the intercooler, not used for combustion) is the roof scoop on factory intercooled Exige models.

Your sequence is essentially correct (you could add after the airbox and before the supercharger it goes past a throttle body, and that fuel is injected into the charged air in the intake manifold just before entering the cylinder). After that its your usual four-stroke Otto cycle.
 

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Discussion Starter #5
So then a follow up question. Since the air, after being squeezed thru the supercharger, is then being cooled by the intercooler, how important is a "cold air intake" that is placed in a high pressure zone to an Exige S then?

In other words, does it really matter where the intake is placed since the supercharger is actively sucking in air?
 

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So then a follow up question. Since the air, after being squeezed thru the supercharger, is then being cooled by the intercooler, how important is a "cold air intake" then to an Exige S?
Now that's a can of worms... it's actually quite important, since cooling the charged air increases the volumetric efficiency of the engine (more power), among other things. There are many threads discussing ways to make the Exige S intercooler more efficient, including changing roof scoops, changing intercoolers, injecting water/methanol, changing to an air/water intercooler, and many more. Many ways to attack the same problem (more efficient cooling of the air heated by the supercharger during compression).

EDIT: I just reread your last line... the supercharger is not sucking "cooling air" through the intercooler, its sucking air to be used in combustion. For an air to air intercooler to work properly, "cooling air" must be traveling through the intercooler at a sufficient rate to cool the charged air, otherwise the intercooler loses efficiency. There are questions about how much air flow the stock Exige S roof scoop actually provides.
 

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You are doing great, keep asking questions. That's how we all learn.

Remember, there is intake air for combustion and there is ducted air for cooling. I think you have it figured out.
 

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Discussion Starter #10
.... the supercharger is not sucking "cooling air" through the intercooler, its sucking air to be used in combustion. For an air to air intercooler to work properly, "cooling air" must be traveling through the intercooler at a sufficient rate to cool the charged air, otherwise the intercooler loses efficiency. There are questions about how much air flow the stock Exige S roof scoop actually provides.
Hmm. I realize that the supercharger is not sucking cooling air through the intercooler. The supercharger is sucking air through an intake and then the air gets sent to the intercooler to get cooled down because as a result of compression the temperature has increased and has expanded.

My question is if the intake air going into the supercharger would benefit from a "cold air intake", meaning just a intake that is placed in a high flow area of the air stream about the car....

Am I making sense at all? hahaha...
 

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All things being equal: yes, cooler air at the intake is better...

The problem is that it isn't that simple. Dynos show that the stock airbox is just fine... or, "cold air intakes" that keep the stock MAF geometry.
 

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Discussion Starter #12
You are doing great, keep asking questions. That's how we all learn.

Remember, there is intake air for combustion and there is ducted air for cooling. I think you have it figured out.
"Ducted air". Good term. I gotta keep that in mind. Thanks, Thomasio. Your solution to the intercooler heatsoak issue looks tasty, btw.
 

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Hmm. I realize that the supercharger is not sucking cooling air through the intercooler. The supercharger is sucking air through an intake and then the air gets sent to the intercooler to get cooled down because as a result of compression the temperature has increased and has expanded.
Hmmm... I'm not sure you've got this part straight. The charged air is at a higher pressure (compressed) and higher temperature because of the supercharger. The intercooler cools it by exchanging the heat of the supercharged air with the cool (actually lower heat) of the air ducted through the intercooler from the roof scoop. It also slightly loses some of its pressure due to the expanded cross section of the flow of charged air through the intercooler. Whew...

Remember, the intercooler is much like a water radiator... "ducted air" goes through it to cool the fluid... in the intercooler's case the fluid is charged air.

My question is if the intake air going into the supercharger would benefit from a "cold air intake", meaning just a intake that is placed in a high flow area of the air stream about the car....

Am I making sense at all? hahaha...
Oh, sorry, I see what you mean. As Thomasio said, it's not that simple. That said, the side scoop is probably a higher flow area than the stock Exige S roof scoop.
 

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Discussion Starter #15
Hmmm... I'm not sure you've got this part straight. The charged air is at a higher pressure (compressed) and higher temperature because of the supercharger. The intercooler cools it by exchanging the heat of the supercharged air with the cool (actually lower heat) of the air ducted through the intercooler from the roof scoop. It also slightly loses some of its pressure due to the expanded cross section of the flow of charged air through the intercooler. Whew...

Remember, the intercooler is much like a water radiator... "ducted air" goes through it to cool the fluid... in the intercooler's case the fluid is charged air.



Oh, sorry, I see what you mean. As Thomasio said, it's not that simple. That said, the side scoop is probably a higher flow area than the stock Exige S roof scoop.
Thanks for all the info, guys. It's good to know....
 

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It also slightly loses some of its pressure due to the expanded cross section of the flow of charged air through the intercooler.
Interesting point. The pressure drops at the inlet tank of the intercooler, because of the expanded volume...

What then, when the volume is constricted again at the outlet tank of the intercooler? Shouldn't the pressure rise back to its original value?

The reason that it cannot rise to its original value is that there are pumping losses between when the compressed air enters the inlet tank, "smooshes" through the core (sorry for the technical jargon), and then into the outlet tank of the intercooler.

All of that "smooshing" takes energy (here: heat and pressure) away from the compressed air. The "smooshing" also creates back pressure that lessens the supercharger's efficiency...

We are okay with losing heat... but, all things being equal, we'd like to preserve the original pressure.

If we can design an intercooler that looses less pressure through the "smooshing" process, yet can still cool the compessed air as well as the original intercooler (or better), the engine would benefit.

Shame someone doesn't have something that can do that. ;) :popcorn:
 

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Shame someone doesn't have something that can do that. ;) :popcorn:
Hey, you know I'm subscribed to your thread!! I'm not quite ready to be on the bleeding edge... I want to see installed pics and data. Yes, I know you're working on it. -poke-
 

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Hey, you know I'm subscribed to your thread!! I'm not quite ready to be on the bleeding edge... I want to see installed pics and data. Yes, I know you're working on it. -poke-
Subtle as a flying mallet, yes? rotfl
 
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