Stock Air Flow Numbers and Mod

[apimpdad]

well my mileage jumped from about 14.8 to 15.45 when i filled up today. i will see if this continues in the following weeks.

[cleanb13]

I bought a used airbox from a fellow member and had every intention to do this mod but now I'm thinking about moisture getting in the airbox and I certainly don't want that. I guess if I route the pipe downward or to the side it may decrease the chances of moisture getting in. Has anyone noticed alot of moisture (not from serious 4 wheeling) in their airbox with the mod done?

[Burger Steak & Eggs]

I have had it for a while now including some wet and slushy days. No problems.

[Hi Volt]

I have obviously had the mod in the longest and have no issues what so ever with mine. I routed the inlet pipe from behind the right headlight. My choice was for 2 reasons. First it was a fairly direct route through to the outside, and second the metal behind the headlight was very clean after 6 years and 200,000 mi of driving in all weather. If you locate the inlet for a ram air effect then you will get much more debris in the airbox. The location I use serves the purpose of increasing airflow and also stays clean ( see photos from mod ). Before my mod, there was dirt in the bottom of my airbox from the stock inlet hose, there is also a water drain hole ( stock ) to get rid of moisture. Just recently I had to travel a few blocks down a flooded road that was 2 feet under water, the wheels kicked up alot of water and I was concerned that water might have sprayed up behind the headlights. I checked the airbox right after and everything was dry inside. My inlet goes out straight, however you can certainly run a 90 degree down bend. A buddy of mine in NC recenly did up his 4.7 in a '06 4-runner, he used a 90 degree downbend ( because of clearance on the body ), and also left the HC filter in, he says he definately notices a difference.

[Captain J]

Back when I had a tacoma, I put a deck plate on the stock air box.

They have a cover that screws on with a o-ring type seal if you are going to a muddy place.
I usually left it open when driving on the highway even on rainy days and never had moisture in the air box.

just a thought.

if you live anywhere near the water, you can get these for about $5.00 at any boaters supply store.

For you inland guys, maybe ebay, or the interweb.

there is a lot of info on this mod over of TTORA website.

[Burger Steak & Eggs]

Would that be taking in hot air from under the hood?

[DH]

I'm very interested in this and was wondering what the verdict is after some use. This is perfect if it works. It makes the engine run more efficient instead of trying to add something. As for dirt in the bottom of the air box, who cares! This is actually common is other makes I've owned.

Bottom line is everyone who did this mod happy and are there measureable results (in your opinion)?

Thanks,
Dan

[Burger Steak & Eggs]

I give it two thumbs. Track tested, no butt-o-meter.

I want to try some piggyback electronics at some point to re-optimize the air-fuel ratio at full throttle, as these engines tend to run rich, apparently.

[DH]

I'm going to do this but want to come out of the air box with two smaller hoses maybe 1" ID each. I don't want to cut any metal to promote rust. I was thinking of running two hoses into the area behind the right head light without cutting any metal.

Any thoughts on this and will two 1" ID hoses be enough?

[Burger Steak & Eggs]

Yours is an 06. I haven't seen the fender snorkel from the older ones, but I am guessing they are smaller. In other words the HC filter removal and K&N swap may be the bulk of the gain for this mod on the later Gen 1s.

One of the guys I work with did this to his 06 bus in stages and although he was satisfied with the final performance improvement, he felt the hose addition itself did not provide the bulk of the added air flow because the 06 has a large duct between the passenger's fender and the bottom of the airbox. It certainly won't hurt to add the hose though. If you want a rough idea how two 1" hose compares to a single larger hose for potential air flow, how about comparing total cross sectional areas of the hoses?

[benbeaux]

Here's my version of the air box mod. All supplies were purchased at Lowes...

Parts: About $20

(2) feet of swimming pool vacuum hose (1.5" ID) $3.07/ foot.
(1) 1.5" shop vac floor sweeper. $10
(1) radiator hose clamp to fit OD of hose. $1.50
(1) 1.5" PVC Trap adapter w/ nut. (PVC 104P 1.5) $3
RTV silicone sealant or suitable substitute (Household Goop, etc)

Tools:

Phillips screwdriver
10mm nut driver or socket & extension
knife
2" hole saw
drill
Hacksaw or sawzall w/ steel cutting blade or dremel if you like to suffer.

To start:

Loosen hose clamp between air box & intake plumbing. Unlatch & remove top of airbox. Be careful not to stress the wiring for the MAP sensor. Lay it to the side.

Loosen the (3) 10mm bolts holding the bottom half in & lift it out.

Drill the 2" hole for the PVC adapter 3" in from the side that's facing the radiator & 2" up from the bottom. Clean out the shavings. Try to land the starter hole on top of a vertical reinforcement. The ones on either side will hold the nut, while you turn the adapter to tighten it. You will have to trim what's left so the nut will fit.

Prep the PVC trap adapter by trimming off the "closed" end of the nut, making it a regular nut. I used my sawzall & metal cutting blade to do this. A hacksaw may have been safer. A dremel will work, but it'll be a hassle since the plastic will probably melt & make a mess. The walls of the box are not thick enough to allow the nut to tighten down, so the nut has to be trimmed...

If push comes to shove, you can just glue the threaded end into the hole & let it cure. I wanted the mechanical connection along with the adhesive sealing.





Reinstall the bottom half of the air box with the PVC adapter installed. Tighten the (3) 10mm bolts.

Next, move the A/C line that's passing through the 2"x2" hole to the left of the condenser over towards one side of the opening. This is required before the hose will pass through. Loosen the 10mm bolt that's clamping the A/C line in place & slide the line over, being careful to not stress it or allow metal to metal contact. Depending on the truck, you may have to move the line up/down/over. Mine had to move to the right.

Slit one end of the pool vac hose & trim out a notch to allow the clamp to squeeze tight. Slip the radiator clamp on, insert the floor vac adapter & tighten the clamp. Don't try to kill it, just get a snug slip fit. You can even glue this connection, if you want.



Wrangle the floor vac adapter behind the bumper & wedge it behind the lower grill. If you want, you can drill a small hole on either end & use a zip tie to hold it to the grill. Tension from the hose was good enough for me.




Run the other end of the hose through the 2"x2" opening & over towards the air box. Leave a little extra to bend around the A/C lines & to hold tension on the hose so it can be wedged into the adapter. I didn't glue this so the air box can be easily removed for cleaning or other service. The fit between the hose & adapter is fine, no further clamping or sealing needed. Trim as needed.



Drop in air filter, replace top of air box & tighten clamp between air box & intake plumbing.

Enjoy your 30 extra HP & 12 more miles to the gallon.

[KLINDSEY]

Originally Posted by benbeaux

Here's my version of the air box mod. All supplies were purchased at Lowes...

Parts: About $20

(2) feet of swimming pool vacuum hose (1.5" ID) $3.07/ foot.
(1) 1.5" shop vac floor sweeper. $10
(1) radiator hose clamp to fit OD of hose. $1.50
(1) 1.5" PVC Trap adapter w/ nut. (PVC 104P 1.5) $3
RTV silicone sealant or suitable substitute (Household Goop, etc)

Tools:

Phillips screwdriver
10mm nut driver or socket & extension
knife
2" hole saw
drill
Hacksaw or sawzall w/ steel cutting blade or dremel if you like to suffer.

To start:

Loosen hose clamp between air box & intake plumbing. Unlatch & remove top of airbox. Be careful not to stress the wiring for the MAP sensor. Lay it to the side.

Loosen the (3) 10mm bolts holding the bottom half in & lift it out.

Drill the 2" hole for the PVC adapter 3" in from the side that's facing the radiator & 2" up from the bottom. Clean out the shavings. Try to land the starter hole on top of a vertical reinforcement. The ones on either side will hold the nut, while you turn the adapter to tighten it. You will have to trim what's left so the nut will fit.

Prep the PVC trap adapter by trimming off the "closed" end of the nut, making it a regular nut. I used my sawzall & metal cutting blade to do this. A hacksaw may have been safer. A dremel will work, but it'll be a hassle since the plastic will probably melt & make a mess. The walls of the box are not thick enough to allow the nut to tighten down, so the nut has to be trimmed...

If push comes to shove, you can just glue the threaded end into the hole & let it cure. I wanted the mechanical connection along with the adhesive sealing.





Reinstall the bottom half of the air box with the PVC adapter installed. Tighten the (3) 10mm bolts.

Next, move the A/C line that's passing through the 2"x2" hole to the left of the condenser over towards one side of the opening. This is required before the hose will pass through. Loosen the 10mm bolt that's clamping the A/C line in place & slide the line over, being careful to not stress it or allow metal to metal contact. Depending on the truck, you may have to move the line up/down/over. Mine had to move to the right.

Slit one end of the pool vac hose & trim out a notch to allow the clamp to squeeze tight. Slip the radiator clamp on, insert the floor vac adapter & tighten the clamp. Don't try to kill it, just get a snug slip fit. You can even glue this connection, if you want.



Wrangle the floor vac adapter behind the bumper & wedge it behind the lower grill. If you want, you can drill a small hole on either end & use a zip tie to hold it to the grill. Tension from the hose was good enough for me.




Run the other end of the hose through the 2"x2" opening & over towards the air box. Leave a little extra to bend around the A/C lines & to hold tension on the hose so it can be wedged into the adapter. I didn't glue this so the air box can be easily removed for cleaning or other service. The fit between the hose & adapter is fine, no further clamping or sealing needed. Trim as needed.



Drop in air filter, replace top of air box & tighten clamp between air box & intake plumbing.

Enjoy your 30 extra HP & 12 more miles to the gallon.

After reading all these post in this forum I have one question, What if anything did any of you do to the inlet tube from the fender to the airbox. Close it off or leave alone? And I wish I could get 30 HP & 12 MPG more with this mod.
Thanks
Kevin

[apimpdad]

Originally Posted by KLINDSEY

After reading all these post in this forum I have one question, What if anything did any of you do to the inlet tube from the fender to the airbox. Close it off or leave alone? And I wish I could get 30 HP & 12 MPG more with this mod.
Thanks
Kevin

Leave the stock tube from the air box to the fender in place.

[cleanb13]

I completed my mod and here's what went into it. I don't drive the truck that much due to the gas prices, so I can't honestly feel a difference. The mod was pretty easy to complete. I didn't want to cut any sheet metal on the truck and I wanted the tube pointed away from moisture and dirt. I used a toilet gasket to seal and take up some of the excess thread on the piping. I decided to go with a 2" pipe instead of something smaller, like other members used. I will let you know the difference the mod made.

[MATRDguy]

Not a bad Mod BUT..I started to get a little rougher idle...anyone else experience that? . It might be the platinum plugs..I'm going back to std NGk's.

I can feel the Mod work when I get on it, but day to day except for passing didnt really do too much. I have a stock box I'm thinking about putting back in to see if I can feel the difference.

I think MPG went down a little...maybe it's from all the Ethanol in the gas up here in MA....CT is worse...( the ethanol content)..