Bob_98SR5

Intake Silencer Removal Mod
Installed on a 2nd gen 4Runner with a 3.0 V6
10/29/2002


Corey (Blu on the forums) shows you how he did a mod to his air box here to improve the torque and HP on his 4Runner.

This is the same mod that Dr. Z did to his intake on the 3.4 engine. Blu has confirmed that there is more low end power on tap. Looks like a very well worth mod to do for those of us who have the 3.0 engine.


The 1st thing I did was remove the air intake pipes from the intake and the airbox.
The next thing to do is remove all the pipes that are associated with these pipes.
This is done by removing 4 hose clamps.
There is a silences box under the side of the airbox that needs to be removed.
There is a hose that goes to it so you must 1st pull that off.
Then undo the 2 screws that hold it to the air box.
After you have done this take it all out of the engine bay.
You should have all of this out if done correctly.

Here's what we're removing:








The next step is to go get the parts.

2' of flexible furnace ducting ( to make the mock set up) - Hardware store
5" of rubber hose 3" inside diameter - Hydraulic supply store
4 - hose clamps ( I used 4" ones) - Hydraulic/hardware store
1-90 degree 1/2" brass fitting , 2 washers and 1 O-ring to fit this fitting
(one end has to push a hose on the other has to have threads) - Hydraulic/hardware store
1-90 degree 7/16" brass fitting , 2 washers and 1 O-ring to fit fitting
(one end has to push a hose on the other has to have threads) - Hydraulic/hardware store
1 nut to fit the 1/2 fitting
1 nut to fit the 7/16 fitting - Hydraulic/hardware store


After getting these parts take the flexible ducting and make a mock set-up.
Bend it to fit between the intake air inlet and the airbox air outlet.
Watch out for the Master cylinder as it is a tight fit.
If you make the bends correctly you can miss it by about 1/2 an inch.
You also have to get the length measurement right. Mine was around 15 3/4 inches.
Once you are satisfied with your mock pipe, take it to a muffler shop and get them to bend you a piece of 3" pipe exactly like the one you bent using the flexible ducting.

Below are some pictures of the mockup:





When I got home from the muffler shop I cut the 3" rubber hose in half , 2 1/2 " long. I put on of these on the intake and the other on the air box outlet. I then put the pipe i had made in place between these two. This was to check for overall length. Mine I had to cut some off as it was too long. I did this with a hack saw. Once it was the right length I did a test fit. I put the pipe into the rubber ends. I then marked where the valve cover hose I took off the original pipe was going to fit. I put mine in the same place, about. I went to the other end by the air box and marked where the 7/16 hose that came off the Silencer that goes to the engine was going to be put. I found that if I ran that hose over top of the distributor then to my pipe it would be a perfect fit. Once I was happy with where the 2 hoses were going to be placed I went and drilled them.

For the 1/2 inch brass fitting I used a 9/16 drill bit. The 1/2 " drill bit was too small. I drilled this hole. I made a test fit. I had to file the hole a bit to get a perfect fit. Then I took a round file and cleaned out the inside and outside of the hole to make it all flat and even. Also took of any burrs or rough edges.

For the other end of the pipe where the 7/16 fitting will go, I used the 1/2" drill bit. I drilled this hole. I made a test fit. I had to file the hole a bit to get a perfect fit. Then I took a round file and cleaned out the inside and outside of the hole to make it all flat and even. Also took off any burrs or rough edges.

Once the holes are all drilled I took the pipe and a metal file and cleaned up any sharp edges in the ends. I did this because I cut my hand on one end. I filed mine so they were fairly smooth inside and outside.

Then I took my air hose and blew the pipe out. I gave it a quick wipe down. Then I sprayed throttle body cleaner inside and outside to get rid of any oils or foreign material that was left. I took a new clean rag and wiped the inside and outside one last time before I painted it.

I taped the holes on the inside so no paint would get in. I took a few rags and stuffed one in each end so paint could not get in that way neither. I took some Tremclad Flat Black and painted it. After a few coats and fully dried I went on to assemble everything on to the tube.

It is now time to put the fitting on. I wanted an airtight system so this is what I did. I put the a washer on the threaded end of the 1/2 brass fitting. Then I put the O-ring on after the washer. I put the fitting in it's hole. If you done this right the O-ring should be between the pipe and the washer. I then put another washer on the inside of the pipe on the fitting. Then I put a nut on the threads and tightened it all up. I put it on the engine a couple times to get the fitting in the right place for the Valve cover hose to fit nice.


continued...

Bob_98SR5

I then took the 7/16 brass fitting and did the same. I then took throttle body cleaner and cleaned out the fitting and the pipe one last time before I installed it. Make sure you get none on the paint as it will take the paint off.

Cut rubber hose with clamps near by:


Various pictures of the fittings being attached to the 3" pipe:









2.5" hose attached to air box:


Pipe installed on engine without emission hoses:


Here's the finished product, looks great:




If you choose to do this mod good luck, and if you have any questions private message Blu on the Yotatech Forum.

NOTE: You should use some type of liquid lock washer to ensure that the fitting inside the tube doesn't work itself lose and get sucked down into your intake. That could be a very expensive fix if that happened.



END