RSR

One of the more popular changes on these boards for throttle response is to remove the air intake deflector behind the headlight -- drivers side for 3vze and passenger side for 22re (Probably less needed on the 22re than 3vze -- like a lot on these trucks, the stock intake setup is probably optimized for the 22re and 4 cylinder diesel, not the 3vze V6). Or, to remove the filter box in entirety and slap in a cone filter. Both of these are often done with the intake silencer removal mod (ISR mod).

Both cone filters (sold as cold air intakes, but truly not) and removing the spoiler only serve to draw air into the engine that is hotter than outside ambient air. Without the spoiler, air will flow through the radiator (which warms the air), hit the engine (and draw more heat off it it), before working it's way up (hotter air rises) and being drawn through the air box/cone filter in the engine. The goal of air intakes is to increase the number of oxygen molecules in the engine. Colder air is denser than hot air and has more oxygen per given volume -- and that's the principle behind genuine cold air intakes (cone filter "cold air intake kits" are only truly cold air intakes if they have a cold intake box created that isolates the cold air intake from the heat of the engine bay, which most don't do).

Today, I did a quick thermometer test, and at idle parked with engine and cooling fan running, the ambient air in the engine bay with hood down at air box location was 60 degrees above outside ambient air (150* w/ 90* outside air). With engine off, the ambient air in the engine compartment was still 40* above outside ambient air (130* w/ 90* outside air). As discussed, at a given volume hotter air directly correlates to decreased engine performance...

So here's my quick and dirty solution -- a true cold air intake and a slight ram air boost too. (The best option would probably be to build a new air collector and cold airbox, but that's not the route I went.)

First here are some pics of the stock setup.
Main intake holes between headlight and side marker light:


View of those same holes with headlight and grille installed:


And showing the ~1/4 to 1/3" gap extending all around the headlight (top bottom and sides), from top:


Same gap, from bottom:


The pic above shows my first stage of drilling 1/4" holes that was quick and dirty and just tried to add some greater air flow while not drilling in the DOT stamp. Well, I did the math, and those 14 holes equaled only about 2/3rds inches squared of increased air flow. I decided I wanted at least an addition 1 square inch of air flow, so I added 5 more holes.

Why 1/4"? I wanted to ensure that the add'l holes since allowing air to flow straight through didn't allow in a lot of debris, didn't severely compromise strength of this piece of metal, and this size fit well w/ my circular file to clean out the holes, pictured (to get rid of shavings I filed through both front and back and scraped picked at anything left with my screwdriver).


And last but not least, here's what the deflector looks like -- extends about 3/4 across the width of the headlight and across whole headlight opening:


Top view:


Two more views:




So to get to 1 square inch of air, I needed 19 holes (slightly below 1 inch w/ math, but with the filing I was doing on the holes, I was surely above or near an inch of increased airflow). For those of you doing this in a more deliberate fashion, you'll probably be able to fit 24-25 holes in a way that better optimizes air flow than I did... I was fairly haphazard. You definitely want the holes biased/more numerous more towards the right than left.

After drilling, file and then sweep/vacuum/blow all of the metal shavings out of the area. From bumper, engine compartment, etc. You don't want metal shavings anywhere near your air intake!

My final hole setup after drilled and filed:


And here's my final hole setup after painted -- both front and back:


New air intake holes (believe this is actually the 14 hole pic) with grille and headlight installed:


The final mod was closing up the 3/4" or so gap between the top of the deflector plate and frame to increased the ram air function (forced air function) of the new setup:


For this foam, I used some A/C and/or plumbing foam, about a 6-8" section cut in half, and some exterior grade double sided tape. I first loosened the bolts holding the deflector in place and installed the 8" section with part of the foam going between frame and deflector. Then tightened the bolts. The second slightly shorter piece, had to trim, went beneath the installed one to push it up and fully seal the gap. Once in place, I cut and placed the foam tape to hold everything together. (There is foam in place on sides with stock factory setup.)

Results:
-I first did the 14 hole setup and noticed improved power at high speeds. Not a lot, but noticeable especially on highway hills.
-Then I did the math and realized the numbers weren't where I wanted so did again, with more holes and foam.
-This, due to ram air and the extra holes, doubled to tripled the minimal gains seen with the first iteration.
-Throttle response seems improved overall, but nothing too significant. Maintaining speeds much easier on the highway at high speed has been the most noticeable improvement.

Also, the stock setup, just the right side holes directly intake air. With my mod, it's the bottom and right that get direct air, with the openings around the light getting deflected air (a slight restriction but shouldn't be significant).

I have not yet done the ISR mod, but I suspect that this is probably equivalent to 1/3 to 1/2 of the performance gains seen from that mod.

Hope this helps some of you also thinking about ways to improve your intake.

RSR

Continuing the airflow discussion further -- above principle is to keep air drawn into the intake as cold as possible. (And cold air also helps to prevent predetonation/knocking, allowing you increase timing higher than if you're drawing in hotter air.)

The ISR delete also serves to this as well by moving air intake up and away from the exhaust manifold -- stock not only has bends that disrupt airflow, but it also sinks the air intake down to right above the exhaust manifold!
With the ISR delete, my recommendation and what I'm thinking there is a 3" mandrel bent pipe or 3" silicone hose -- the first is better flow and the latter will transfer less heat to the intake air. So if going metal, I'm thinking either high temp ceramic paint (cheap), a more expensive proper ceramic coating, or possibly in combination foil heat resistant wrap.

The next challenge is air filter. How do you provide sufficient filtering while also increasing air flow. K&N and their equivalent dry filters do not provide sufficient filtration. They allow a lot of dust in -- and dust contains a lot of abrasives, including microscopic metal and stone, that eats away at the engine and, regardless of dust composition, deposits throughout the intake increasing restriction.

Oiled filters also serve to crud up and ruin the expensive AFM, so aren't ideal.

On one of the non-yotatech forums (think 4runner.org or something), folks with 3rd generation or newer 4 runners tried the K&N cold air intake cone filter kits w/o air boxes and dynoed and found that they actually lost horsepower and torque over stock too...

And over at Bob's, the air filter experts argue that for everything except for supercharged or turboed engines, additional airflow over stock isn't even needed for CFMs engines require... http://www.bobistheoilguy.com/forums...Number=1595175
So if a high flow filter isn't necessary or even the point of restriction, why increase wear from with a high flow filter?

Here are the options for filters as I see them:
-Multipurpose cold air intakes w/o box
1. K&N - high flow but oiled is bad and poor filtration
2. K&N's AEM Dry Filter - high flow dry but poor filtration
3. More modern synthetic filters like Volant Powercores - good flow and filtration
(But none of these is ideal w/o a cold air intake box, which no one makes specifically for our vehicles, so it's a more complex custom job)

-Drop Ins
1. K&N oiled filter - high flow but oiled is bad and poor filtration
2. AFE Pro Dry - high flow and poor filtration ( )
3. S&B Dry Filter - high flow and better filtration http://www.sbfilters.com/Stock-Perfo...tton-Cleanable
4. Wix, Denso, or OEM Paper - lower flow (but sufficient CFM flow for engine needs) and highest filtration

Research on S&B vs standard paper and afe and AEM (by S&B however -- some have discussed quality control issues w/ S&B throughout the interwebs): http://www.sbfilters.com/Filter-Types

The benefit of drop ins are that you get to keep your factory cold air intake, which is designed for our specific 4x4 vehicles that operate in less than ideal conditions (on the AFM supra swap there are some pics of the supra airbox and the supra uses essentially the same filter as our 3vze trucks but it's oriented vertically -- air flows straight through -- whereas our filters air flows from bottom to top to keep moisture out of our engines/from destroying the engines).

Ideally, we'd have a modern foam or synthetic drop in filter available for our trucks, but we don't and options as I can identify them are above.

For now I have paper Denso (purchased before doing any of the above research, etc, but I also suspect if flows better than standard paper too with near paper filtration numbers and better than S&B, but no numbers http://www.autopartsway.com/PartDeta...33-1629959/ND/), but of the current options outlined above, would personally only consider S&B for a change -- and am not currently convinced of the need.

Gamefreakgc

Interesting mod, I like how you are thinking on this one.

It would be good to compare with the spoiler off completely as well, to see if the if the cold air with the spoiler on is better than hot air with the spoiler off. I know that when I still had the stock air box on that removing the spoiler increased my throttle response at all levels, cold and hot.

In response to the second post, if you do the ISR delete and increase piping, it's not going to do you any good. The reason being is that the air flow meter's opening is too small. That's why I swapped to the 7MGE afm. Here's why:



Bigger opening allows for 3" to be useful. Otherwise just run 2.5", you won't notice any difference.

But then your spoiler mod will be useless, since these don't fit in the stock 3VZE air box.

RSR

Yes, planning to the AFM swap eventually too (that's why 3" rather than 2.5" piping, and the spectra intake couplers I think are for 3" but with a 2.5" sleeve included), but irrespective of the AFM swap, doing the ISR mod should increase performance due to less restriction in intake tubing, and -- I think -- less heat transferred to intake air due to current intake location being maybe an inch from drivers side exhaust manifold. I think the Camry one does fit our airbox, but haven't really progressed that far down that trail. Some other maintenance and whatnot I'm wanting to do first. Eventually if doing the AFM mod, I may just go w/ a custom, sealed airbox of some sort reconfigure all the vacuum lines/boxes and rotate the radiator overflow as some have done so I have a much wider air to collect intake ram air from... I do like the spoiler/collector configuration on current though -- funnels all air from a larger area into where it's need, should capture/deflect most moisture before it enters the airbox, etc.

Here's the full sizing specs by the way on the AFM:
-stock 3vze, AFM has a 2.585" internal diameter and an area of 3.69"
-2.9" inside diameter supra AFM and an area of 4.79"
Source: https://www.yotatech.com/forums/f88/...54/#post409801

Eventually, I want to do the crossover delete too, which should be a big help w/ keeping the engine compartment cool, and accordingly keep the upper intake/plenum cooler as well -- it gets pretty toasty (which actually helped with the Amsoil Intake/Upper Plenum cleaning process I posted a couple days ago) as does everything else in the engine compartment with current configuration.

RSR

Edit: wrong thread, but I'll leave it as I guess it's related.

Actually, here is the throttle body article I remembered:
http://www.off-road.com/trucks-4x4/r...ody-23080.html

big bear

Anyone ever make a custom hood scoop and filter box ??

RSR

I haven't seen air boxes for the 3vze. I've seen some folks do them however. Usually some thicker flat, clear polycorbonate sealed with sensor safe silicone where applicable. If you look at the Supra AFM swaps, there's a lot of folks that rotate the coolant reservoir -- just rotate the bracket to opposite side I think -- and that should allow space. Combined with some foam insulation around the edges of the box, you should be good.

There's enough air flow holes and actually a cap on part of the frame -- probably an 1.5"-2" diameter -- that still avoid the radiator air that should be more than adequate add'l airflow to not do my mod. I just wasn't sure that I wanted to delete the EGR silencer as a lot of folks say doing so is really annoying, and with having to go through emissions inspection, I don't want to have any problems if I need to swap parts back in...

For whatever reasons, the next gen 4runner forums seem to attract a lot more modding than do forums related to the next Tacoma. And I think that's where I've seen some custom boxes... Basically you just need to seal the air intake filter from the engine compartment so that it's drawing cold air instead of engine bay air.

And IMO, that's the big failing of a lot of aftermaket "cold air intakes" that do include side deflectors but fail to add a fully sealed top covers. I suppose that maybe with larger engine bays you can get away with it, but not in our trucks, and not -- I'd think -- in any truck you want to be able to go through big puddles and splashes on or off road and not suck water.

Insofar as hood scoops, usually folks add them for cooling/forcing air down the back of the engine to keep it cool on account of that danged crossover -- or vents near rear of the hood for the same. I think you can get much of the benefits of a hood scoop from a properly designed collector/air box as discussed above. Should be a good 1.5-2 ft of collector frontage once rotating that coolant reservoir. I just don't know how you'd design an aerodynamic collector. I guess maybe some couplers with decreasing plumbing pipe sizes w/ caulk/sensor safe silicone? That polycarbonate is probably easiest to keep square...

The next gen 4Runners has factory hoods with scoops, and I have wondered -- but never researched -- if they'd fit our trucks (for me, to help w/ cooling the rear of the engine).

Gamefreakgc

Yeah, the smog component is tricky. With my setup, I can return to bone stock by just swapping the hoses and it's done!



Note that the blue filter isn't there anymore, I realized that it was for the A/C idle up and would almost stall when idling with the A/C on, there's a hose now. You'll see though, I just am sucking in hot engine air so I'm interested if you do find a way to bring in some cool air! I thought about just running piping down below but it would suck in too must dust in the summer and too much water in the winter.

BTW, it's the PAIR reed valve that's stupid noisy. I can't remove mine due to the above mentioned smog checks. Thankfully, it's only loud during cold starts and decelerating. Although, it makes my truck sound like a beast at WOT!

I'm seriously considering running water/meth 50/50 mix to cool my truck. Then it doesn't matter what temp my engine bay is. Though if I don't end up doing it, I'd be really interested if you find a creative way to draw cool air in, especially for the Supra's larger air box.

Yeah, that's because they can actually get HP gains out of the 3.4L engine. With ours... not so much. There's a little here and there but not a whole lot to be gained.

RSR

I saw someone use a thick plastic throttle body spacer after their K&N cone filter but before the AFM, and put a threaded pipe fitting there to run the pair hose to (knew it was one of those...) And reported that got rid of nearly all of that noise. Could probably find some sort of thick hard plastic to do the same.

Scrussanation

cant wait to do this mod... although with my s&b i think i can make a badass air scoop underneath grill or bottom bumper... havent decided yet but will be doing foam insulation and it will be a true cold air intake... and noticed your in central, tx RSR im near central sometimes too... mind me asking where?? you ever go near any hill country or south tx?? could always do a show and tell in person lol

RSR

Scruss -- My big thing w/ the air intake is that in the event I need to cross water, even though mine isn't a hard core off road rig by any means, I want to ensure that any chance of my rig sucking water is avoided -- being in the hill country you know how that goes w/ rainstorms and flooding you know how it can go.

Going through that frame down is probably the easiest way to get more air and would follow the curve and how I think the supra probably ingests air...

I think to get more air in a way that minimizes water intake would probably require more drilling.
In this pic there's a plastic black plate in the top left of front frame/top left of AC receiver dryer as well as a sizeable hole below that I thought could be removed/hose added for increase airflow, but it would have to be piped around and/or under the coolant reservoir to get air to the airbox (you can see the coolant overflow screw hole just above it and to the right).


I'm thinking I'm going to want to remove the air deflector at some point and do the math. Visually the pipe from deflector to box looks smaller than is ideal. And I should really try to measure the air intake ability of the front headlight stock holes as well. (My mod above does definitely make a significant difference however and am happy with it thus far).

While rotating the coolant reservoir like gamefreak did creates more frontage, when taking into account the grill design and existing holes, there's really not much add'l airflow even if you double the size of the deflector. So I'm stumped short of drilling more holes to the left of the headlight and hoping the little air the grille does let in there reaches the intake piping...
I suppose pulling some air from the fender wouldn't hurt, but that fender to airbox bend is the primary point of restriction in the 3.4 5vzfe intake setup -- so long as it's a supplement and not primary flow, it should help, but being out of primary air flow, it'd also negate any rammed air gains you get from the stock setup (air could go from front to out fender instead of using it as an add'l air intake).

I'm in the ATX metro. Sometimes get west into Hill Country, and have been wanting to get more out to Kerrville and Lost Pines area once it cools off a little...

Scrussanation

haha I live in Kerrville and work in South tx near dilley during the week running my mobile rv repair.. next weekend your in the neighborhood stop by!!

Gamefreakgc

I like what you are thinking with the secondary hose through the holes you mentioned. I've notice lately that when I'm doing city driving or errands my idle speed plummets to 500ish RPMs because it sucks 150-160 degree engine bay air. However when looking at the supra air box again, it's roughly twice the size of the stock 3VZE opening, so I'm looking at probably twice the holes or openings. I think your drilling idea is spot on with a secondary hose pulling from in front of the radiator. That way at WOT, there's no restriction which would defeat the purpose of my engine intake mod! Pair that with the foam you mentioned, I think it can be done. I just need to figure out how to get it around the coolant reservoir, I can't rotate it back since it doesn't fit.

skipper0802

RSR,
Your quick measurements agree with the results I found after I concluded my report. Glad to see we're measuring and understanding. Nice work!