Okay so maybe its the guy in me but the temptation of the shiny chrome tubing to the nice k & N filter looks very appealing to me, but at the same time the price persaudes my decision making process to an idle... I mean ya they are a little pricey i dont care who you are... I have read through a few threads on here and i have noticed that some love them and others hate them. One member posted that K&N's hp gains only come at 4K rpms... and like he said my highway driving is normally lower than 3K. So i need your guys help are these things worth it if your not using a programmer... and also if you are, are they still worth the cost.

 

Simply.. No. You will have to drive for 1000's of miles to get your money back.. If that. Depending on your vehicle you might have to drive 10,000s of miles.

This is made even more of an issue because a CAI by itself wont do anything. When you upgrade your intake capacity, you must upgrade the output capacity (exhaust). Thats another $100-300.

Power and MPG increases will be minimal. Both CIA and exhaust are supporting mods, and by themselves (even a CAI and exhaust) wont do much alone. They will need a tuner to fully use them.

 

If you do an online search for “air filter test” there is a lot of very good information. IMHO, the CAI units are NOT WORTH THE $$! Unless you are talking about a system that was specifically designed for a specific application there are very little hp/tq gains actually achieved in a street use vehicle and there are very few docs that these mfg’s can produce that actually show an increase in hp/tq in the power-band range of a relatively stock street vehicle.

I would avoid oil impregnated filters. While they have their purpose in off-road applications, Ford/GM/Dodge all have “watch-out” bulletins where the oil has contaminated intake sensors. - they even have a training video for the techs on this (flatratetech.com) .

If you look at the flow data, WIX HP filters flow 98+% of K&N and have a much smoother flow post filter plus excellent filtering, for a fraction of the price! The OE’s have an excellent air intake system. What many view as an issue (is the plastic intake tube with its noise canceling design) actually increases air pressure. It is the same hydraulic concept used by fire fighters creating water supply where psi is low. By having the air cross the path at a 90 degree angle, the pressure is increased proportionally. Fire fighters use what is called a “4-way valve” or “Blake Valve” at the hydrant where the water is cycled through the fire engine (pump) and sent back into the valve crossing the water flow at a 90 degree angle. In this case it also acts as a sound canceling device! At low speeds, this can reduce the flow a tad (which is what most “feel”), but in terms of peak hp/tq, a good high flow filter is all that is needed. You can use a WIX OEM HP replacement filter in the OEM plastic manifold box and either remove the plastic tube and replace it with a piece of pipe/hose, etc or remove the tube completely and replace the tube by building an air ram type intake into the air box manifold (where the pipe use to attach)- make sure it terminates above the fan shroud to avoid water intake or fan induced pulsations.

With regards to cfm flow, The oem software system is designed to adjust the fuel mixture up to 10%.......that’s more than enough to handle fuel mixture adjustments up to 7,000 foot elevation change! (for high elevations 8,000+ there are oem software programs for those specific applications) The 5.4 V8 for example if close to stock can only suck in a maximum of 480 cfm and a flat panel filter will flow 500 cfm, there is simply no way any CAI on a relatively stock engine can increase the air flow enough to exceed the ECM’s ability to adjust and maintain the correct fuel mixture.

 

I'm sure many will disagree with me, but here it goes anyways. Your stock intake on any fuel injected engine pulls air from outside the engine bay, aka "cold air." Where as all the aftermarket kits are an open element in the engine bay with some cheesy 'block off plate' that is supposed to block all the hot air from the engine bay. Simply, they don't work. You end up with hot engine air in your intake and no gain in power. But the added sound from the open element gives the impression of more power just because you can hear the motor a little better. If you really want a different intake, get a different intake tube. Most stock tubes have reverb chambers and mufflers built in so that it's quiet. Easy fix, get a tube that just goes to the intake, no added chambers or any of that crap. Also material makes a difference too. The stock soft foamish stuff dampens sound. PVC or metal of any kind will yield more sound. So, by k&n consumer logic, that makes more power.

 

The warmer-air-than-stock-under-the-hood-bling-intakes are quite simply not worth it unless 1) you are operating routinely above 4500 RPMs and 2) you get a custom tune to account for a modified MAF transfer function.

 

I'll never buy a CAI again. No gains in power. Just noise & poor filtration.

 

Most cars/trucks these days come with a Cold air intake from the factory

 

I've got a friend with an 03 4.6 supercrew with a k&n. It sure sounds cool! Otherwise, he still gets about 14mpg, including having a magnaflow catback and a superchips tuner. Of course, he keeps his foot in it the whole time cause of the noise. I definitely wouldn't buy one new....

 

I had a K&N fipk on my 97. No gains unless you like noise. It ran better times with the stock intake. Cooler air I guess. I got tired of fixing the K&N. It would fall off if you hit a pothole. K&N sent my new hoses but they got hard & did the same thing. I sold it & put the stock one on.

 

Sorry about bumping this thread, but I just had a question

Looks like all of you are asking about power bumps on EFI engines.

I'm running a '72 460 in my '79 truck. Naturally, it has a carb. It has an Edelbrock 14x2 diameter air cleaner. Because it's taking air from inside the engine bay, the air is warm. So if I buy a kit like the Spectre Performance Cold air intake, and I route the lines forward and cut holes in the radiator support, I should technically see a increase in torque?

From what I can tell from readings in this category, if you have a stocker EFI engine, a CAI is just a waste of money. But my engine is carbed, and it's definitely not stock.


Thanks for the help
Jameson

 

Now I'm going to show my age.....

Yeah, did that and it does work but we typically did not see any hp/tq increase until you hit 70+ mph (and then you're only looking at a couple hp or so). To gain the most, you need a "sealed airbox" like the hemi ram air system from the 60's.

Now real world.....you will probably gain better throttle response (from increased air flow) from double stacking the round air filter as compared to anything else.

The old formula for figuring what minimum size round air filter you need is...
Surface Area A= (CID) (RPM) divided by 25,500
H= A + .75 divided by (D) times (3.14)

Key: A= Filtering Area D= Estimated Height H= Height
Note: For Off Road Use Multiply Height 1.5 to 2


FYI...a stock 460 with a max rpm of 5500, has a max cfm of 550-600.

 

That logic is lost on me. If you double stack air filters, you are just restricting flow. Sure, it might not be much, but you are still restricting air, not increasing it


First, this isn't a stock motor. I said that in my last post. Its really far from stock

Second, I think something went wrong in your math there;
displacement: 460
mutiply by max RPM: 6000 (nature of the cam, crank/pistons)
equals 2,760,000
divide by 3,456
equals 800 (rounded from 798.6)

Thats the absolute maximum air velocity requirement (AVR). Most driving will take place between 80 and 90% of maximum

Maxmium AVR: 800
times .85 (85% happy medium)
equals 680 daily driving needs. 700-750 carb works good for this

 

You are right....I typed 500 when it should have been 650-700

Now, like you know, you have to add in all your perf mods......20% cfm increase typcially hand;es most street mods (as a general guide)

You are actually doubling the surface area, therefor, twice as much flow capability- but you need to run the formulas to determine what the minimum size air filter should be. When I say double stack (an ol term from the 70's), you are actually using the round filter housing, replacing the rod/bolt with a much longer one that the top of the air cleaner attaches to & taking the same exact air filer element, purchasing a secoond one and placing it on top of the 1st one....doubling the height, you typically can only do this on

 

So then cfms would be equal to about 820 for daily


Anyway, that double stack makes more sense now. Problem is, I don't think 4 inches of filter will fit under my hood. the intake is taller than stock.

 

Yeah, properly tuned an 800 would work, but you will likely have to make a jet and other adjustments- but I'm assuming at 20% increase, that you have a cam (much more than an RV style), modified heads, headers, intake, etc..also take into consideration that the truck is a heavy vehicle, so a 750 might be work a little better re: throttle response (low end)....a little less tuning on the 800.