hamiltonj2w1

I just ordered my K&N cold air intake has anybody else done this on there 4th gen and if so how is it performance wise and all that good stuff? I already have a Magnaflow exhaust

LSUSYCO

I can't speak of 4th gens, but I put one on my 3rd gen. it's louder than it used to be and I do notice a small increase in MPG.

LSUSYCO

deserttoy84

Just be careful when you oil the filter. Too much can mess up the mass air flow sensor.

Toyvana

K&N Frequently Asked Questions:

http://knfilters.com/faq.htm#20

William

The bad thing about the K&N link is that they are trying to sell you something. There's alot of hype associated with freer flowing air filters/cold air intakes, and their website doesn't help matters.

Yes, their filters and cold air intakes have the ability to flow more air. But does that mean that your truck will be able to breath in more air? No.

The limiting factor on most vehicles is generally the heads, or some componant other than the filter/airbox/intake duct. If something else is limiting flow, then how can adding a different filter/cold air intake kit allow the vehicle to flow more air? It can't.

By the way, modern vehicles already come with a cold air intake.

And modern engineering methods allow engineers to optimize the intake for flow while dampening noise anyway, and they have designed the factory intake to match the rest of the system.

Plus, keep this in mind: If there happens to be more air flow, the fuel injection system will automatically compensate by adding more fuel. The mixture would be the same, but there would be more fuel added to go with the air. How could fuel economy possibly be better when more fuel is being added as well?

Then there's also the controversy on many sites about the K&N not filtering as well as a stock filter. Many argue about the K&N being used being used in Baja racing, and how those engines last just fine. But those engines are rebuilt after races, so you can't use that as an example.

If a factory replacement K&N can flow more air, the only way it can do that and still be the same physical size is to filter less.

AppleJack

I am going to have to disagree on a couple of your points there William. The truth is that your engine can breathe in more freely by eliminating the air box. The heads are a limiting factor to a point for sure, but it's not really volume but how quickly and efficiently your engine breaths and how cold the incoming air is.
Breathing through a straw vs. w/out will demonstrate it.
However if you don't have and equally free flowing exhaust, it would be rather pointless to have.
Do you feel the power? I didn't. they can be almost nauseatingly loud when your throttle opens up for extended periods of time(i.e. climbing long steep grades).
There's a little better throttle response in the winter and cooler temps.
In the summer I think I lost hp. as it was sucking in hot air from inside the engine compartment with no cooler outside air to combat it. So not really a "cold air" intake at all.
So IMHO it's not worth the dough!!!

Sporticus

There was a guy on TN who put a scanguage on his truck with both the stock and the K&N intakes. The stock intake actually registered lower air temps (by a few degrees) than the K&N did. Take that FWIW.

I have a K&N intake for my 05. Like was mentioned before, it is loud and it might get you a miniscule increase in mpgs. Don't go looking for horsepower, though.

BTW- My K&N intake is for sale for $100 if anyone is interested. COmes with a red filter cover.

juddemt

before i get started, this is basic physics and gov't laws. factory intake is designed for decreased air intake for quietness and better emissions. it's also designed with a bunch of bends and crap for removing any water or mud that might get into the intake. you cna suck a lot more air through a straw that is short and straight that a straw with bends and restrictions.

I put a k&n cai on my 02 tacoma v6 4x4 auto. the rpm shifting points lowered a little and i could go up hills and overpasses without the engine immediately wanting to downshift.
I made the mistake of trading it in and buying a 06 tacoma v6 4x4 trd o/r 6spd manual. the first thing i noticed was that the rpm's "hang" when you change gears. i put a k&n cai on and i immediately noticed a difference. the engine was more responsive, the rpm's didn't hang, yes it makes noise but i like that, and i also noticed that my mpg's dropped. wtf? i rarely rev higher that 2500rpm. i had also purchased the drycharger cover for the filter since it's an off road vehicle and there's no barrier (casing) between the filter and the outside world. so i decided to change yet again to the trd cai because the filter is encased. with this cai i got the same responsiveness but not as much noise. and the filter is protected. and best of all, my gpm's increased a tad. about 30-40 more miles per tank.
i like my trd cai. you can tell the engine breathes better with the cai.
sorry its lengthy

William

I can't say for sure about the Tacoma, but on most modern vehicles, unless you modify the the whole engine and intake and exhaust (heads, intake plenum, intake manifold, throttle body, headers, catalytic converter, muffler, exhaust piping), a cold air intake or freer flowing filter does very little or no good.

Wherever the most restriction is, if the most restriction is not in the filter and/or airbox, then a cold air intake and/or aftermarket filter most likely won't increase maximum air flow.

If the heads are the most restrictive part of the engine before an aftermarket cold air intake is installed, the heads will remain the most restrictive part after the installation.

Lets say the heads have the ability to allow 600 cubic feet per minute (CFM) of air to flow at a certain RPM. If the intake has the ability to flow 800 CFM, the engine still couldn't have more than 600 CFM of maximum flow. Why? Because the heads still limit the flow to 600 CFM.

If the flow is 600 CFM at the airbox inlet, it is still 600 CFM at the throttle body and at the intake port.

And consider this: What if the throttle is half closed? Will the aftermarket intake help? No! Why not? because the throttle, when half closed, is limiting the air flow.

Any increase in air flow that an aftermarket intake might allow would happen at or near full throttle.

Back when I had my '94 Mazda Navajo 4wd (same as a same year 2 door Ford Explorer), I joined a forum site called The Ranger Station (for Ford Ranger based vehicles such as the Explorer/Navajo). There is a guy that is a member there named Michael A.K. Gross. He is literally a rocket scientist. He works for NASA, and knows alot about various types of engines, right down to exactly what happens in a combustion chamber.

I used to believe alot of the hype associated with K&N filters and intakes. After reading alot of what he said about what pysically happens inside an engine, and the affect (or lack thereof) an aftermarket filter/intake has on an engine, I no longer believe it.

An 30 year old carburated vehicle might benefit from a cold air intake. But it's very unlikely that a fuel injected modern vehicle (which already has a cold air intake and has the benefit of computer aided engineering) will benefit.

William

If I were to get an aftermarket intake, it would be the TRD intake, because it's designed by the same engineers that designed the factory intake. Plus, Toyota engineers are some of the best automotive engineers in the world.

DIHOWARD

i like mine just fine. i have a 4.0 and yeah, its louder than stock, but not that much. as far as the person who said not to look for HP. It also says he is selling his with the red filter cover, might have something to do with it.

87Toy22r

And I wanted an k&n air filter!!!