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2.9L Cold Air Intake


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So I've read the tech article on here about the K&N Air Filter with the angled inlet (it's actually for a 2011 & up Toyota Tundra, oddly enough) being mounted directly to the throttle body. I did it on my old Ranger, and I really liked the way it looked.

The problem with the factory air box is obvious: it's right on top of the passenger side exhaust manifold, and it sucks in all the hot air coming up from it. My question is, however, even though the K&N mod puts the filter kind of in front of the cooling fan, it is DIRECTLY on top of the upper radiator hose, so wouldn't it just be sucking in hot air from the hose as well?
 


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2.9l should be fuel injected

All Rangers with fuel injection had Cold Air Intake(CAI) from the factory

The "air box" should have a tube running to a hole in the rad support, so air was pulled from in front of the rad support, cold air.
There should also be a Pre-heated air duct with a vacuum valve, on cold start the valve would cause air to be pulled from around the exhaust manifold, heated air, instead of from rad support duct.
This allows faster warmup when temps are very cold.

Any air from inside the engine bay would not be considered CAI, air must be pulled in from outside the engine bay, like from in front of the rad support.

CAI was first developed from Carb setups, air intakes sat in the middle of engine bay.

The physics of it is a normally aspirated cylinder can pull in XX amount of air.
Cooler air is denser than warm air, if air is denser then you can add more fuel.
So cylinder pulls in XX warm air and you can add x amount of fuel
Cylinder pulls in XX cold air you can add x+1 amount of fuel

More fuel added means more power, this is why engines are "peppier" in cold weather and also why MPG goes down, lol, can't have it both ways :)

Pretty much every fuel injected vehicle has CAI from the factory now, also tuned exhaust.
 
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2.9l should be fuel injected

All Rangers with fuel injection had Cold Air Intake(CAI) from the factory

The "air box" should have a tube running to a hole in the rad support, so air was pulled from in front of the rad support, cold air.
There should also be a Pre-heated air duct with a vacuum valve, on cold start the valve would cause air to be pulled from around the exhaust manifold, heated air, instead of from rad support duct.
This allows faster warmup when temps are very cold.

Any air from inside the engine bay would not be considered CAI, air must be pulled in from outside the engine bay, like from in front of the rad support.

CAI was first developed from Carb setups, air intakes sat in the middle of engine bay.

The physics of it is a normally aspirated cylinder can pull in XX amount of air.
Cooler air is denser than warm air, if air is denser then you can add more fuel.
So cylinder pulls in XX warm air and you can add x amount of fuel
Cylinder pulls in XX cold air you can add x+1 amount of fuel

More fuel added means more power, this is why engines are "peppier" in cold weather and also why MPG goes down, lol, can't have it both ways :)

Pretty much every fuel injected vehicle has CAI from the factory now, also tuned exhaust.
So would the K&N swap actually DECREASE efficiency as compared to the factory set up?
 

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If factory setup was working correctly then, yes, pulling air from inside the engine bay would decrease available power.

Generally speaking most "bolt-on" changes only increase power if the factory system was failing.
Which is why you read stories of "I really noticed a difference when I added..............."
So stories are true if looked at in that aspect.

But when people do independent tests with dynos there is either no change or a loss of power, with most bolt-on gear

A good paint job doesn't make it go faster, but if it looks good why not.
A new exhaust doesn't make it go faster(assuming factory exhaust was good) but it makes it sound better, so why not.

You make your vehicle yours, unique.
If you want powerful and fast you don't buy a Ranger, lol.
If you want a powerful and fast Ranger you put in a V8 or 4BT
 
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If your factory air box is sucking right off the manifold then there is a piece missing (like on mine).

It should be sucking from the grille.
 
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If your factory air box is sucking right off the manifold then there is a piece missing (like on mine).

It should be sucking from the grille.
The air box is located on the passenger side wheel well, is that not where it picks up from?
 

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The air box is located on the passenger side wheel well, is that not where it picks up from?
Under the air box should be another large plastic conduit. Measures about 2" wide and about 4" long. Hanging off that will be the hot air/cold start vacuum valve that diverts the system over to drawing air off the exhaust manifold (if it's still there? You'll see about a 2" flexible metal tube attached to the heat shield on the manifold. When stone cold that valve allows for warmer air for better cold performance. Once the engine is warm enough, the valve diverts over to the front air intake--which is a nice cold blast of fresh air.)

That air conduit goes under the battery (at least that is how it was on my prior Bronco II 1989) And the air gets introduced via nice cool air flow next to the radiator.

Most of the "Cold Air Intake" modifications aren't doing anything noticeable. We call them "Hot Air Intake" due to the fact all the thing does is suck hot engine compartment air into the engine. It's nothing more then a placebo effect in about 95% cases. I know K&N is a respected 'brand'.... And they do make excellent oil and normal higher flow air filters. But the tube nonsense that sucks ANY air from the engine compartment is a waste.

It's like the teen age child that puts a "Fart Can" exhaust on his car along with a huge spoiler and thinks he's got a race car. All he has is something to feed his ego....and doesn't do squat for real engine performance.

S-
 
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So if the only true "cold air" comes from outside the engine bay, does that mean a snorkel would technically be a true "cold air intake" and thus bump up performance, even if only slightly?
 

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The "bump" in performance was from the old days of carbs sitting in the middle of the engine with air cleaner sitting on top sucking in warmed air from upper engine bay.

If you already have a CAI then changing it's intake location wouldn't really change performance

Why CAI is used:
In the old Carb days Hotrodders ran tubes to front grill or cut holes in the hood to get cooler air for the engine.

"Hot air rises", hot air balloons float up into the sky because of this.
So warmer air is lighter than cooler air, warmer air is not as dense so "floats" on cooler air, it weights less.

Gasoline engines run on a ratio of 14.7 to 1, air to fuel, this is a WEIGHT ratio.
If you have 14.7 pounds of air, you can add 1 pound of fuel.

2.9l engine means it can use 2.9 Liters of air every 2 RPM, 4-stroke engine needs 2 RPM for one cycle.

A Liter is a VOLUME measurement, so if the WEIGHT of a Liter of air is more, then more fuel can/needs to be added, if less WEIGHT then less fuel.
If your 2.9l engine sucks in 2.9 liters of cold air then slightly more fuel is added so slightly more power.


And just FYI, this is why "pre-vaporizers" and 200mpg carbs were a myth, lol.
These use VOLUME in their "cons", and that's what it is.

You do need an efficient dispersion method to mix the fuel with the air, intake fuel injection does that, direct injection is even better.
But you still need 1 POUND of gasoline with 14.7 POUNDS of air to get a good power burn
 
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this is all sound advice for what the application is. a nutless 2.9...


moving the intake of the stock"snorkel" higher or to the cowl is ideal if you have a 4x4 or live in an area you routinely traverse some flooded roads, otherwise stay out of water. inverting the stock piece and adding a tube to the cowl is pretty easy to do. two birds, one stone


14.7 is far from max power in a dynamic situation of course, and in motion the hot air intake is not necessarily a hot air intake, this is dependent on the actual underhood airflow dynamics. many....hell MOST factory systems are far....FAAAAR from ideal. simply the best or cost effective compromise of goals for noise vibration and harshness and its ability to withstand alaska to florida temperature ranges for the average tom, dick and jane...and sail thru emission compliance. the so called tuned intake and exhaust systems from the oem only until literally the last few years, leave allot on the table for those wanting to maximize a vehicle to their specific requirements/climate or ideals.

when measuring intake air temps in dynamic operations things change drastically depending on the actual vehicle.



that said

i dont suggest a k&n for the average driver, as it is a waste of time and money like mentioned for the average bear.

but be sure of this, they have key advantages for offroad and competitive situations, though most wont ever need such a thing..and will allow more power over any oem paper filter offered to this point...

and also be sure of another thing..used incorrectly it will shorten the life of any engine. and the vast majority of users i have seen dont take the time to adjust them and clean up after initial run in. myself included at times when i dont care about buying fuel or shitty idle...

for hotwire airflow systems they are the devil for the average user, it takes patience to work with these things and keep performance optimal.
 

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