JohnnyCanuck

P.O had a k&n cold filter system on my truck, looked like junk - sounds even worse than it looks - and with all the dust up here I tore it out and put the oem system back on from my parts truck.

Yotafreak81

Kind of a newb. I have a 94 4runner 3vze, and considering the ISR mod possibly doing it this afternoon while the wife is at work, When you do the ISR mod do you have to reset the ecu/computer ( Im not sure if this is the correct terms) and if so how do you do that? Pull the Fuse? disconnect the battery? Project will be underway in a couply of hours so hopefully some one can chime in and help out by the time I start. Thanks in advance of any replies.

skipper0802

Here's an easy, and sensible start to quantifying (benchmarking) how the OEM intake system performs. This lets us talk apples-to-apples, and allows the elimination of terms such as "feels like," "likely," "probably," etc.

I'm going to start here to help answer my first question:
http://www.autospeed.com/cms/article.html?&A=0629

RSR

The K&N is one of the worst filters you can buy. Personally, I'd avoid any oiled filter and opt for dry.

S&B does have some analysis studies on their website: http://www.sbfilters.com/Filter-Types

Personally, I'd prefer a foam filter like True Flow or modern synthetic filter like the Volant PowerCores or Amsoil Ea -- but I'm really happy w/ the 3 layer Denso I'm running..

The completely enclosed cold air filter boxes that S&B has are a good first step, but you'd still need a way to completely seal the gap between the front of the engine bay and the Cold Air Intake, else you'd be drawing in hot engine air...
I discussed this recently over here -- and I think you could rotate your coolant overflow tank and allow enough frontage to get a pretty good air draw: https://www.yotatech.com/forums/f116...or-mod-272014/ Edit: Gamefreak already beat me to, but that's my thinking anyways, haha.

And you'll also want to really read through the ISR mods (a lot of folks slap on a K&N cone with that) to ensure all the vacuum connections you're deleted are tied into your new system properly. The pair hose needs to go between the filter and AFM for instance or else you'll get a lot of weird noises...

RSR

ECU computer fuse under the dash is used to reset. Or disconnect the battery negative for at least 15 seconds on both. The ISR shouldn't matter too much though... But it couldn't hurt I guess.

RSR

On 1, I would say it's better (less restrictive). Why? - the air flows straight through the filter, rather than in and up then back.

On 2, I would say it's worse (allows more water in). Why? - the air flows straight through the filter, rather than in and up then back...

Essentially, stock uses gravity to keep moisture out and the deflector plate serves to help with this quite a bit as well before even reaching the box.

RSR

I didn't know anyone made a kit for our truck. This is good to know. Probably easier than manufacturing... I am curious as to how this ties into our stock AFM though. I can't tell how it would work from the pic as that tube appears to tie into the throttle, but perhaps I'm looking at it wrong? If you can get a picture of an installed setup, I'd love to see it. Worst case their filter should be easily swappable with some of the better other aftermarket ones...

RSR

Picture's once installed please!!!

Gamefreakgc

Or MFI fuse in the engine base fuse box. That one won't reset all the settings on your ECU, just ones pertaining to the air/fuel ratio and long term fuel adjustments. And yeah, you don't really need to do it for the ISR mod.

And Skipper0802, it's not hard at all. All I did was slice open the rubber sealant and adjust the cog. Just release the metal prong and spin it. It's all outlined in the thread linked in my signature. It's one of the easiest mods you'll do, finding a donor engine is the hard part (there's several different AFMs for Supras and Cressidas).

Yotafreak81

Thanks for the heads up. Mod is underway...... waiting for the wife to get home so i can make another parts run, got a few of the wrong sizes on intake tubing(oops), it was nap time for the 2yr old when we went and he wasn"t letting dad think clearly. I disconnected the battery already, we will see how that goes. Again thanks for the help. Will post when I am done.

Yotafreak81

I am keeping the stock air box with K&N filter that was on the 94' when I bought it( considering changing it out), just getting rid of the other three "silencer" boxes and running straight tube to intake. Running new PAIR hose and other 3/8 hose cant remember what it is called and PCV hose. Just wanted an excuse to work on the 94' I guess.... We will see if it makes that much of a difference. If it doesn't, stock will go back on. No loss but $30 for misc parts and a couple hours of my life........lol.

RSR

That's for next generation btw, they have a tight bend from filter box to fender air intake, sort of like what we're deleting with ISR mod -- only tighter, and that's what is being referenced. Actually, IMO it's a more restrictive air intake pre-filter than what the headlight intake setup is on our trucks. Their filter to engine cylinder is far better than ours however.

Here's theirs (top is start of intake at fresh air, bottom is end of intake at intake plenum):


That's why folks are saying to delete that elbow/turn portion that goes into the fender and put in a better elbow and tubing w/in the fender...

RSR

I'd keep your pair box/hose as is if you're keeping your stock filter box. Don't agree w/ the K&N filter swap. Look at the other post I & gamefreak referenced as to why. I'd start w/ just the ISR mod if I were you. The deflector mod I did really helps too -- I haven't done the ISR yet.

RSR

I will add that you can't even see the holes that I added for increased air flow unless you're actually looking for them. It's only about a 1/4 to 1/3 inch gap between the front grille headlight housing and the light itself -- slightly less than width on the head of that screw.

It looks large when close:


But once you step away with no light, you cannot tell: (this is passenger side but mirror image of drivers and the same gap size -- the gap between headlight and grille headlight housing, not the gap between grille and bumper)


Even if installing a new cold air intake, you'll still want to have some sort of collector/gatherer to pull air through the grille rather than from engine bay. Unfortunately, the stock grille isn't ideal for pulling air through it, even if rotating your coolant reservoir.
On the truck, you're still going to be behind the solid grille portion and no further than halfways towards the V6 emblem on the mostly solid black portion that will be available to you for "air collection" -- and most of that will actually be initially deflected before entering through through the grille (that's part of why I added those holes where I did, it's pretty much a direct intake rather than an additional deflection prior to intake...):

skipper0802

Hey RSR,
Thanks for the links. I like reading that S&B has done ISO 5011 testing for their filters. K&N also uses ISO 5011 for their evals. Their test format and results are here. The reason I bought an OEM replacement K&N 24 years ago was because it's cleanable...and I wouldn't have to toss another piece of plastic into the environment. I don't know if Volant PowerCores were around 24 years ago, but I'll check them out

I'm going to do some baseline measurements of the OEM intake system per the Autospeed.com article series. This will include airflow pressurization just outside the grill near the headlight, and above the hood just above and behind the headlight. The purpose of my testing will be to quantitatively prove or disprove that an external intake will have an airflow equal or better than OEM and that said airflow will be cooler compared to an intake behind the grill. I want to use real-world data collected by driving the truck in my usual manner.

Just bought my fittings to test the anticipated pressure drop in the intake just before the TB. This should give me a value to compare to standard atmosphere pressure for the intake system ala Autospeed.com. I'll seek the least intrusive method to do this, i.e., I'll fasten and seal a 1/8" vacuum hose barb to the VC breather hose elbow. Pictures to follow. Whew, that was a lot.

Yotafreak81

You have me confused.........in this post you said the K&N is not good. The K&N drop in filter was installed by the previous owner on my 94 4runner. I was considering going back to paper filter or something other than K&N oiled filter. So Should I keep the K&N or not?

RSR

No, I just read your post too quickly -- sorry. Yes, I'd switch to either a drop in dry high flow (S&B's look pretty good, but some have alleged quality control issues on the interwebs, and really the extra flow probably isn't needed/the air filter isn't a primary restriction point in the intake) or a paper one -- OEM, a 3 layer Denso like I have, or Wix would probably be best...

RSR

You have a great plan. Really looking forward to the results!

Btw, I did test the underhood temps at air intake location under the hood +60* parked and at idle and plus 40* of driving at highway speeds, pulling over and turning off engine, and then testing the temp...

I *think* and suspect the air flow pattern across the top half of the engine (most of this being air warmed through the radiator) is probably a circular motion from front to back down middle, at least 1/3rd to 1/2 (1/6 to 1/4 going to each respective side) of the top flow going out in each direction towards the fenders, and that air heading back towards front -- causing the air intake to predominately suck air warmed by radiator, engine, and ambient heat from exhaust manifolds (main flow through radiator out pressuring air intake through headlight)... And once hitting front of the engine, the air is forced down into main bottom flow or recirculates in the top flow...
The balance of top air goes down and out the back with main bottom half flow -- straight through.
But your results might find different!

RSR

Oh, and good point about K&N's tech. They were best available hi flow 20 years ago but tech has changed substantially since. K&N does make an AEM that's pretty identical but dry. And there's an AFE drop in that I think is pretty similar to K&N/AEM but dry as well...

JohnnyCanuck

Nice, post some pics when you get it installed.