mikes19984x4

some were saying that they're "gping back to stock" in some of the previous posts, after they said they used various aftermarket filters like trd, amsoil, and K&N. and not trying to start an arguement here, so correct me if i'm wrong, but if the K&N will flow more CFM of air, then shouldn't it have at least the potential to make more power than stock...

cackalak han

Ok, dude, you have to think things through with a bigger picture in mind. OK, technically, you're probably right. You DO get more air flow with K&N vs. paper (along with oil and dirt). But how much will that really affect HP? .05? .005? Plenty of dyno runs have been performed using drop-in K&N filters and the results are almost no gains at all in every instance. Again, is 1HP (to be generous) worth the hassles of owning a K&N?

Wife's 4runner

Trueflow convinced me...and I live in a fairly dusty area. I am ditching the K&N. It's for sale.

mikes19984x4

okay man, i see what your saying about it now... ...as most people buying K&N buy it due to the factor they will never have to buy another filter, unless for some crazy reason they destroy it...lol! so it might even be safe to say most of these drop-in aftermarket filters will only see some of their actual potential released when in setups with smoother flowing intake tube, such as doing the ISR and deckplate mods...

mt_goat

Only if the stock filter is hindering flow, do you really think the Toyota engineers would have picked a filter that wouldn't flow well enough to make max power or provide the best MPG? My supercharger doesn't have any problem sucking enough air though the stock OEM filter to make 10 psi of boost. And I don't even have a deck plate mod. IMHO there is no flow problem with the stock Toyota filter, hence no gain. There are only downsides to the K&N. Without an oil analysis to check for high silicon levels you don't know how well your filter is doing for your driving conditions.

In my 50,000 mile expenence with a K&N (on my old 3.0 engine) I went from using no oil to using a quart every 3000 miles. And I noticed an increase in dirt in the intake. Yes, it is a 4x4 and yes, I was wheeling on dusty trails, but that was the only engine I've ever owned (35 years of looking in the rear view here) that started using oil. It only had 115,000 miles on it when I took the engine out and was run with full synthetic oil at 3000 mile oci.

The poster who mentioned the air filter to air box fit problem makes a great point. I've heard that Toyota has a bit of a reputation for letting dirt slip thought the cracks around the filter and the tape idea sounds like a good idea. I'm guessing it was some kind of double sided tape?

mikes19984x4

no,i believe toyota engineers make some awesome decisions to give us the opportunities to have some awesome vehicles. but if your making, for example, max HP of 200 with everything stock, then add in say a K&N with more flow, and do the intake mods that most of us on here have done, wouldn't it increase the max HP that your motor could make? and oem filter can obviously handle plenty of airflow, as no-offense on this one, but 10psi of boost is nothing compared to the boost made by some of today's newest diesels. and on the part about your motor started burning an extra quart of oil every 3000 miles after you installed your K&N: correct me if i'm wrong, but how in the world can an air filter with a higher rate of flow cause a motor to do this?

mt_goat

By letting more DIRT into the engine and causing more engine wear.

mikes19984x4

yes, good point there. but how long did it take before you actually knew it was burning an extra quart of oil? and could this have been a result of improper cleaning/oiling? (not saying that you did this, just wondering, as i'm interested in all the info this thread is getting)

pfdaxe

I ran a K&N when I first bought my Runner. After a CEL and a oil soaked MAF I tried an Amsoil and an expensive Fram. I've even tried a couple of different airboxes and I always go back to the stock airbox and filter. For me, my ride runs the best this way.

It's all a conspiracy for us to spend (waste) money on the pretence that we will gain 0.00000005 HP and MPG

cackalak han

Do you know anything about diesels? How are you comparing a gas engine to a diesel one? Please do some research before spouting out misinfo.

Oh, BTW, 4Runners with intake, header, exhaust amount to VERY small gains.

mikes19984x4

sounds to me like the oil-soaked MAF was from over-oiling, as all the K&Ns i've saw have never been "over-oiled" whenever you pull it out of the box and first install it. and what fram did you try, the one that looks similar to the K&N? just wondering...

pfdaxe

I think it was the extreme Fram or something like that. Yeah...I know I over-oiled. But I still think most if not all aftermarket filters & airboxes/intakes are a waste. Especially on the 3.4L. It's such a gutless underpowered motor that is hard to generate much power out of.

mikes19984x4

do i know anything about diesels!?!?! man, not trying to sound cocky here, but as of right now, the only gas vehicles in my family right now is my 4runner and my mom's jeep. the other 5 rigs are all diesels. and YES!, i know plenty about diesels and probably more than most guys on here, as they are what i have been around for most of my life and i have helped my dad, grandad, and uncle work on all of their rigs whether it be just routine maintenance or making some serious horsepower with big time upgrades. and when i said that about comparing the flow going through the oem filters in a gas supercharged rig with 10psi of boost and diesel rigs making over 20psi of boost stock, it was to back up what mt-goat said about oem filters being able to flow enough CFM. so, tell me how you can come on here and say that i'm "spouting out" all of this "mis-info"?

mt_goat

I'd say it was at least 30,000 miles. Could have been many things that cause it, but I followed the cleaning the recharging kit instructions very carefully the 2 or 3 times I cleaned it. I always allowed it to dry on its own (I used an old stock filter while waiting a day for it to dry) and never used high pressure to clean it. The 3.0 just has a VAFM so at the time I wasnt' worried about fouling an MAF. I first started using oil intrapment filters in the 1960s with dirt bikes so I understand how they work, the more oil the better they filter out the dirt. Not enough oil and the dirt will go right through them, so of course I thought I put enough oil on it each time I cleaned it.

BTW, I've heard of guys fouling MAFs with K&N filters straight out of the box, so you can't just blame the users for over-oiling them (whoever that was). It appears to me to be a fine line between under-oiling them and over-oiling them. Too much oil and they foul the MAF, too little oil and they don't filter as well.

Why in the world there is so much loyalty to this 40 year old filter design is beyond me, especially with the new nanofiber technology that just hit the market in the last few years. If the engineering dept at K&N is only half as smart as their marketing dept, I wouldn't be surprised at all to see K&N change over to it soon.

mikes19984x4

your exactly right on the part about the fine line between over- & under-oiling these filters. and x2 on the part about K&N potentially coming out with some kind of newer filter, as even though i own one, i just can't see them not designing some sort of newer filter.

cackalak han

Then I guess you already know putting a turbo on a diesel is much easier than a gas engine? Diesels can handle much more boost than gas engines, since their efficiency with high compression is not affected as much as a gas engine. Which is why you see more diesel rigs with higher PSI than gas engines. But how you can compare two engines that run on completely different fuel systems is beyond me.

Oh, just because you've been around diesels doesn't mean anything. I've been around gas and diesels all my life and I don't think I am any kind of an expert.

Wife's 4runner

you know, feeling kind of suckered in....sort of like using Penzoil because grandpappy did. K&N is sold at autozone....who is interested in high margins and vehicles which break down....Ok....K&N is coming out.

mikes19984x4

dude this is getting old having to explain this to you... once again, i was comparing the OEM filters that are used in gas rigs, such as mt-goat's rig with it's 10psi of boost, and the OEM filters that are being used in today's diesels that are making over 2x more boost stock. and my comparison has nothing to do with what type of fuel system is being used, as that has nothing to to with the airfilter...want proof, just go look at a Fram filter for a 3.4 yota and then look at one say for a 5.9L Cummins or any of today's diesel's...same material! and all that stuff you just posted about the compression ratios has nothing to do with the air-filter topic that this thread is centered towards. and i never said i was some type of expert, but i'm pretty sure being around them and ACTUALLY WORKING ON THEM them does mean something, as i do know what i'm talking about....

Paul H.

I had a K&N in my 4runner for awhile and noticed no difference when I changed it back to stock filter. Like others have said, I do not like the possiblity of oil going where it shouldn't so I will stick to paper.

cackalak han

mt goat just simply said he was fine using the OEM filter on 10psi of boost on his Toyota. Then you came in with, "oem filter can obviously handle plenty of airflow, as no-offense on this one, but 10psi of boost is nothing compared to the boost made by some of today's newest diesels." Again, why did you bring this up and how can you put any sort of comparision on these two completely different engines? If I am mis-reading this, then my bad, but it's either worded weird or you're making an absurd comparison.

Sorry to go off topic. Getting back on track...K&N still sucks.