[REVHRD4]

Anyone made a list or know the CFM of parts on the 2.4L engine? Like stock intake, stock exhaust, aftermarket intakes, aftermarket exhausts etc...?

 

[arinesmith]

bump

 

[AzKoupSX]

 

[Matemorh]

^^ +1

 

[AutoItKing]

Unfortunately CFM ratings don't really mean much. You can push as much air through a pipe as you want as long as there is enough pressure.
There are standardized tests, but many companies will fudge the results to make their product look better.
In an exhaust the only restriction is the muffler. And the cat if you count that.
The intake is only the filter really.

There is some simple math you can do to figure out how much air is going through your engine at any time. We know the size of the engine, so we can calculate the amount of air that goes through at any RPM.
in a four stroke engine, air is pulled in or pushed out every other revolution. Which means for every RPM there is one liter of air pulled in. Or 1.2 for the SX.
So at 2000 RPM there is 2000 liters of air going in every minute. And from there it's a simple conversion to get the CFM.
To get the flow for the exhaust you have to use some more math to find out how much extra volume the burnt gas has added to the charge in the cylinder. That will tell you how much is flowing through the exhaust.
Keep in mind all of this is in an idealized system, actuall values will likely be lower.

I hope this helps.

 

[arinesmith]

1 liter/minute = 0.035 314 666 213 cubic foot/minute
2 000 liter/minute = 70.629 332 427 cubic foot/minute
6 000 liter/minute = 211.887 997 28 cubic foot/minute

 

[Matemorh]

Which means for every RPM there is one liter of air pulled in. Or 1.2 for the SX.
So at 2000 RPM there is 2000 liters of air going in every minute. And from there it's a simple conversion to get the CFM.

Well, this is true if you asume that air density(or air presure) is at 1 atmospher (or 32inHg or 103 Kpa) witch is false in an intake manifold of an atmospheric engine.
Since it's the piston going down that "draw" air in the engine, there a low pressure generated in the manifold. The more retriction there is for the air to go trough filter/piping/tube bending/manifold etc. the less air enter the cylinder chamber. (air temp. is not considere here)
So once you straithen the piping, reduce filter restriction all is left is the intake manifold!!

 

[AutoItKing]

Yep, I didn't really go too in depth since I'm on my iPod touch right now. Not easy writing a long post, ya know?

Also, the volume will be the same, just a lower pressure than atmosphere.
Now I want to do some stoichiometry... Engineer's curse... We always want to do math!

 

[arinesmith]

I was just curious if putting a fan inline would simulate ram air. Something around 250cfm.

 

[AutoItKing]

I was just curious if putting a fan inline would simulate ram air. Something around 250cfm.

I'd say at least 300, maybe 400. So you can get some good pressure in there. It would have to have a high static pressure too, there's going to be some resistance to push through.
Even if you can keep the pressure in the manifold at atmospheric pressure, that's a pretty good increase in power and efficiency.

 

[Matemorh]

I was just curious if putting a fan inline would simulate ram air. Something around 250cfm.

Yes it will work....... BUT!

You'll have to put such a big fan that will have to spin so fast that the current draw from your new HUGE alternator will negate the gain!!

If you want the engine to dirrectely drive your fan than it's call a supercharger!! .... and driven by your exhaust gaz = turbocharger!!

Here a simplyfied math (very simplyfied!).
Each rpm require half the volume of your engine in air (for a 4 cylinder)
So at 6000rpm for your 2.0liter = 6000 liter of air per minute
and that is just what your engine is curretly "breating"!! You want more performance..... you need even more air!!

 

[Koupsx4110]

Sorry to ignite maybe a dead topic topic, but has anyone seen or used this? Is it worth it for a basically stock engine? OR does this fit in line with the plug and play ECU chips that promise 60-80 hp gimmicks?

Kia Forte Koup Air Intake Supercharger Fan - 10HP+ | eBay

thanks!

 

[arinesmith]

40A fan and only 250 cfm

 

[AutoItKing]

That'll remove about 60hp if anything!

 

[Koupsx4110]

40A fan and only 250 cfm

If i'm reading this thread right, it should be even a little boost then right?

i used to have something like this in my monte carlo, helped a little bit though there was no fan just a bunch of angled surfaces circulating airflow.

 

[arinesmith]

It would pull so hard the engine would have to work harder to run it, neg gain. Law of physics, is why there are only 3 'chargers'. The only thing is sometimes messing up the air flow increases efficiency. Think golf ball, spoiler or vortex generator.

 

[Koupsx4110]

understood thanks.

 

[Tebore]

Just know that you need to move thousands of CFMs to get any boost / Positive pressure in to the cylinders. Anything listing CFM's in the hundreds is just getting in the way.

 

[Koupsx4110]

Ill remember that thanks.

 

[AutoItKing]

Mhmm boost need high CFM and high pressure, hence the name.
But hey, even if you can keep the pressure at 0atm (pressure at sea level), then you're getting somewhere. That's what superchargers on older aeronautical engines did, just keep the pressure at 1atm so there's no power loss as you got higher in the atmosphere.