Then why have back-to-back dynos proven that HP increased and monitoring of the IAT sensor showed lower intake air temp when ONLY a CAI was added.

I had my accord for over a year and it consistently got 27 mpg on the highway @80mph. When I added the CAI intake, by itself, it went up to ~28.3 on average. If the CAI doesn't make a difference then explain to my why my car suddenly started getting better fuel mileage.

Think about this: does a vacuum cleaner get hotter and louder when you cover the suction hose up for a long period? The motor strains more trying to suck in air when there is restriction of any sort. Stock air systems are designed mainly for quiet operation, the have resonators and a large air box that "cushions" the incoming air upon acceleration, making throttle response bad and also making the engine work harder for the amount of air that it needs for the current throttle position. These intake systems also are made mostly of black flexible plastic that heats up from the engine and has alot of sidewall friction. The aftermarket intake systems get rid of the stock plastic pieces with a straight, smooth pipe that is internally coated for less friction and painted externally to reflect engine heat. They are a more direct path for the air to travel allowing outside air to reach the engine quicker.

Short ram intake systems are mainly for throttle response. They sacrifice warmer air temps for a much quicker time between "press the pedal" and "engine jumps" pretty much immediate.

If power is dependent on throttle position and the design of intake runners then a turbo or supercharger should not make any difference in power since the engine can only "intake what the throttle allows. A CAI does not produce positive intake pressure like a SC or turbo, but it does REDUCE the resistance to air flow over that of a stock system.

 

I don't use quotes. Never have and will not use it.
If prople can't relate to what is said and to lazy to read, then tough

 

not even worth my time.....

 

You just made the point.
The changes for the average user are un noticable for the cost.

 

I've got the K&N 77 series with a poweraid throttle body spacer and its cherry. Gives a nice whistle from 2 to 3k rpms.. Also gettin a Granatelli MAF sensor calibrated for the intake.

 

Ok i can gaurantee you that you know more about the "mechanical" aspects of a vehicle because that is something i do not do but your really failing to see some very obvious physics principles here.

Lets start with combustion. Combustion in any engine is never 100% efficient. Get 100% efficency is near impossible.

First of all, i have seen a lot of post on Cold Air Induction and no one has really came up with a reason why "cooler air" is more effecient. No it doesn't have anything to do with making your engine cooler. Well i will tell you. As you cool a medium it becomes more dense (water being the exception when its cooled below 32F above that it follows the rule). Anyways why do we want cooler air? Cooler air will be more dense...hence the air molecules will be closer to each other. So for equal volumes of air, if one is cooler you will have more oxygen. The more oxygen you have in the system the better up to a certain point. Of course how effective the system is would be how much it lowers the temperature of the air (that is debatable). Your trying to super saturate the combustion chamber with as much oxygen as you can.

Why do you think forced air induction systems work so well (turbo/super chargers)? They force air into the combustion process under pressure. Hence more complete combutions.

Its not the size of the air hole that matters but what matters more is the percentage of oxygen. Go look at the difference in gas milage between riding in the mountains on a flat road and riding at sea level. I gaurantee you will see in difference in fuel economy. Why? Again because oxygen saturation as you go up in elevation is less.

So yes if cold air induction does significantly lower the temperature of air or increases the pressure because of the location of the indunction system then it could definitly help fuel economy.

And yes the air filter would matter too. Why do you think a clogged air filter is such a hog on fuel economy? When an engine can't get enough air because of an air restriction in the air induction system them it starts to create a vacuum situation. This is why its starts "sucking". When this happens the o2 sensor will read a lean situation and will try to compensate but injecting more fuel ie which make the combustion process even less effecient (more fuel without any more oxygen).

Edit: i had to edit this post to just say im not arguing that cold air induction systems work. That would take a lot of testing. I am only aruging the fact that the principles are sound and some of the arguments that some people are making are really not true. So yes the could be a gimic and yes they could not lower the temperature of air over the stock induction system one bit but the principles are sound.

Ncage

 

Bluegrass...I would have to pretty much agree! Had a MAC CAI, or should I say HOT AIR INTAKE...fuel mileage dropped slightly and the only increase in power was at full throttle stomping the gas at 70mph or so. Many people get sucked into the HYPE! Our stock intakes work great, and are actual Cold Air Intakes...that need alot LESS cleaning. In fact after about a yr, put my stock intake back on and fuel mileage went back up and the truck runs better than ever!!!

 

Ncage, funny thing, I never mentioned anything about cool air not being denser or any of what you talking about.
But let me tell you, I run a Kenne Bell so don't think your talking to a novice, my friend.

 

First i never implied or said you were a novice i was only saying some of your arguments from a physics standpoing was invalid. I was just trying to explain how/why induction systems work. A lot of people who know a lot about cars don't actually no why things work they way they do.

 

Check out this system that i found at diesel power mag:
http://www.dieselpowermag.com/tech/f.../photo_13.html

Look where the design positions the air intake. Right in the engine compartment. How how in the world would the air in the engine compartment been any cooler than the air from the fender?

 

any good article:
http://www.streetracersonline.com/articles/aem/

 

Welcome to the forum F-250LD 4x4

It looks like you joined right into a good discussion here.

 

Ok you guys in the know, whats the common opinion on the functional ram air hood scoop, works or a waste of pennys...

 

Waste of money. Unless it is very far forward or right at the base of the windshield, it is probably in a LOW pressure area (think of an airplane wing). So its not going to force any more air in.

 

I belive to make a true cold air kit that makes a differnce you would need somthing like the K&N FIPK that blocks the air from the motor and sucks it threw the original hole, the only problem with this is that you probably arent gaining much volume or free flowing air. So opening that hole up would be the next thing to do, widen it and maybe even cut a hole in the inner fender well or something to allow cooler air easyer access to the engine compartment.

I have a "hot air kit" and i cant say as i noticed much of a gas milage increase, maybe 1 mpg, but i did notice more punch when i would get it to kick down at 30 mph.

The truth is that any performance gained by haveing less restriction of air flow is probably off set by the hotter air. So those of you wanting to actually gain some, modify your current air inlet and see if that makes a differnce.