TransAmBandit

Good thing you said that, I was worried about that when I was looking at the clearance for the pipe.

SMOD

K&N you think is a bad idea??
Should I get the toyota air filter replacement? (I'm going to need one pretty soon.. as soon as it gets dirty again I'm going to replace it).

Thanks

mt_goat

That's what I use now, I ran a K&N replacement for about 50,000 miles and noticed some of dirt getting past the filter (inside the intake tube). Plus I noticed no difference in power from one to the other.

SMOD

Hmm,

Was it the cheap 5$ replacement K&N filter or was it the $40 one?
I don't even know... is there a difference?

I probably will get a toyota air filter then.

abecedarian

here have a read by a guy who's done some comparison testing between different air filters:
http://bobistheoilguy.com/airfilter/airtest1.htm


as for the VAFM/AFM and MAF (and I'll throw in MAP as well):

VAFM/AFM- Volume(tric) Air Flow Meter. Uses a vane (also known as door, flapper, etc.) that sits in the airstream. As air passes through the housing, it pushes the door open a certain amount based on how hard it is pushing through- more air needed by the engine means more air flows through, opening the door more. There is also an air-temp sensor in the housing that detects the air temp (go figure?). Using some math, the ECU can calculate how much air is flowing in and the density (how much O2) of the airflow. Given it's a mechanical system, changes in airflow are not immediately calcuable since the vane has some mass (weight) and inertia when it changes position so it is slow to react to sudden throttle changes, hence why the battery/filter swap makes a noticible difference in power- it's so close to the throttle there is little time for a slight vacuum to build up in the intake duct before the AFM reacts.

MAF- Mass Air Flow. Uses a heated wire in the airstream. The ECU monitors how much current is necessary to keep the resistance of the wire constant since air blowing across it cools the wire off thus affecting the resistance. Also, since less dense air will cool the wire less than more dense/cooler air, it does not require a temp sensor in the intake. Some manufactures do incorporate one just in case (usually as a reference for limp mode operation since airflow can be roughly calculated given throttle opening position and air temp). Since it is purely electrical- no moving parts- it reacts very quickly to changes in airflow. This is why most recent systems incorporate a MAF to calculate airflow.

MAP- Manifold Absolute Pressure. A piezo-electric device that sends voltage when the crystals on the device are deflected, expanded or compressed due to suction or pressure applied to it. Most often used in turbo/supercharged vehicles to help the ECU calculate fuel for boost conditions. Not pratical for a primary air-flow sensor but very effective for boosted systems hence their popularity with turbo kits and aftermarket ECUs designed for that application. Most people are most familiar with piezo-electric devices used as the speaker in digital watches, etc., where they vibrate according to voltage but they work backwards as well: vibrations or motion creates voltage.
One other thing to consider when looking at MAP sensors- they are usually rated in BAR, meaning atmospheric pressure. So a 1 BAR MAP can read from absolute vacuum to 1 atmosphere pressure- about 14.7 PSI. Incidentally, a mechanical vacuum / pressure gauge is actually reading 14.7 PSI when it reads 0 on the gauge. So you'd need a 2 BAR MAP to react to up to 14.7 PSI boost from a turbo/supercharger, a 3 BAR MAP to react to up to 29.4 PSI, etc.

That is all.

ironroad9c1

Just a note that if you offroad a K&N filter WILL let more dirt into your engine.stick with paper elements

abecedarian

think I should add:
they outfitted K&N filters to the Apache helicopters in Desert Storm and elsewhere NOT becaused they filtered dust from the air better than paper filters... but because they caught the biggest particles without sacrificing significant airflow. In otherwords the military was willing to accept the most-fine dust entering the turbines (the engines run without filters normally) at the expense of shorter in-air times when compared with good paper filters. Stock= no filter= turbines wear out quickly... K&N= some filtration= more airborne time than stock... paper filters= turbines last the longest, shortest airborne time due to more maintenance to change the filters.

So ignore the K&N marketing blather saying that if they're good enough for helicopters in the dustiest of areas, they're good enough for your vehicle. And honestly, I've put the 40+ dollar drop-ins in my 88 and 91 and didn't notice a difference in performance or fuel economy.

SMOD

Ok, yeah I'm going to go with the Toyota replacement air filter then. I rather have my engine last longer. lol.

ironroad9c1

well I don't have the governments endless supply of money to rebuild my engine due to wear from dirt and dust, so paper it is for offroading, street use, I would use a k&n. plus i worked on goverment stuff back in the navy, They really don't take that good of care of it..lol

SMOD

It's just our tax money, so why would they worry about cost?! They have a endless supply of fake money too!! Lmao.

But yeah, I'm going to be going off road so I'm going to keep a paper air filter.

Thanks for the info, I probably would have spent $250 on the K&N intake if it wasn't for this site.

PS: I gotta get a yotatech sticker to show my support! (I kindda want to make my own though. One that just says: "Smod on Yotatech.com" in white letters)

Jay351

I found I had better access to my dipstick after the ISR mod.. Before I had to reach over it, now I can reach under it...



Good idea. thats what I do

mt_goat

Well here's a pic of it, it was about $40 I guess.

SMOD

Yeah, I guess K&N was just a bunch of hype.. huh.. lol.
Well now I'm thankful I know.

Thanks

tman12345

if i was to get a K&N would you reccommend me getiing a pre-filter?

mt_goat

Funny thing about the K&N, it actually starts filtering better after it gets dirty. Apparently the dirt fills up those little holes in the cotton fiber. If I was forced to use one again I'd never clean it and after about 50,000 miles just throw it away. Or as soon as a good filter was avaliable I'd throw it away. One exception would be guys running dunes in the desert, there frequent cleaning and pre-filter would be a must.

BTW I hate it when people refer to the Toyota OEM filters as paper filters. None of the ones I've seen look anything like a paper filter. They are good filters.

I have a K&N prefilter for a small motorcycle air filter. They make a good fluids filter, I use it all the time when I want to reused a fluid but don't want any tiny particles in it.

mt_goat

Those look like GREAT filters! I wish they made a drop in for my 3.4, I'd try one.

SMOD

Why do you say they look great?
Are you just basing you're reasoning on the description of the filter?

I'm jw, not trying to dis you, you're cool Mr. Goat, you're like the cool goat with a personality that has NEVER existed, because goats (to me) are dead boring. lol!

mt_goat

Yeah mainly the test results and the fact that they are washable, oil-less, and Amsoil has a great rep, that and there are guys on here that are using them and like them. If I had a aftermarket intake I'd use that filter on it.

Godzilla

Well they had their weird foam air filters for the 3.4L before, so maybe it will be available in the future. But, if its like all the other crap (k&n, trueflow, etc..) Ill be returning to my good ol' toyota filter.

Jay351

My friend says the same thing. He runs K&N's in his truck/cars and never cleans them. I still woudlnt run one. IF I can see through a filter then its not a filter. Just an expensive paperweight.

My denso paper filter I got seems to be an original replacment.....