My 2004 Explorer

[4pointslow]

My 2004 is definitely not the same as my 98's.
I was shocked and annoyed to find this out since I have 2 spares for the 98's that wont fit my 2004.
And this engine is 4.0 sohc in my 2004 too, just like my 98's.

 

[CDW6212R]

Interesting. Ford can't stop changes things, even when the previous thing was great.

 

[4pointslow]

I finally made an appointment to have the exhaust opened up to 3 inch on this 2004 Explorer.
Last year when I tested back pressure it pinned the gauge at 15 or so.
Now that my EGR system is finished I want to relieve that back pressure before turning it on.
I am trying out a new exhaust place because my original one made it too hard for me to have it done there, saying they could only do it on a Thursday if I left it all day. The place I am trying next has a reputation for doing it right and not overcharging. I will post my thoughts when it is done.

A side note about the egr system.
My 2004 has a ESM type egr system, ESM stands for egr system module where all three parts are one assembly (solenoid, sensor, and valve).
One design change that I am fond of(from DPFE to ESM) is that when the valve is closed there is no pressure pushing up into the sensor.
And another is there are no little metal tubes coming out of the bigger egr tube for the sensor. The little tubes on the ESM are part of the valve instead.
This made it possible for me to make an egr tube with just 5/8 stainless tube.

 

[4pointslow]

One more thing,
I told the guy I want the quietest 3 inch muffler he has in stock. lol.
The guy thinks I am nuts wanting 3 inch but a quiet muffler.
He was like all this exhaust work for how much power increase?
I answered by saying I wasn't looking for power increase but instead to reduce back pressure.
Then he said oh back pressure before the cats? (implying it had clogged cats) I answered no after cats.
He told me he did not believe me. I said that was ok and he said he could do the job.
He doesn't know I have a supercharger on it, I did not tell him.

 

[delexploder]

Lol thats funny

 

[CDW6212R]

Cool, back pressure, you don't need that big of pipes, you'll never see the difference. LOL.

 

[4pointslow]

I think I might show him the picture of my 98 2 door with the front wheels off the ground.
lol.

 

[delexploder]

one of these days i wanna meet you and go for a ride in that thing lol

 

[vroomzoomboom]

one of these days i wanna meet you and go for a ride in that thing lol

it moves. big time. i couldnt keep up with it when i had the 5L and m90. NO CHANCE lol. and the sound it makes...ive never heard a 6 cylinder sound like that. ever.

 

[4pointslow]

I got the Exhaust done to day on this 2004 Explorer.
3 inch, and the quietest muffler they had in 3 inch.
The Muffler is more restrictive then louder mufflers but I wanted quiet.
The cost 341.21
The muffler is a Quietflow 3 SS
part # 21054

They did it while I waited, only took 2 hours so I was impressed with how fast they are.
However they did not bring me out to see it when finished, just pulled it out front for me to take after paying.
OK whatever, I will get under there when I get home.

First saw the tip and thought "looks good"
Then driving it home was like wow it feels like it has more power, runs smoother, and very quiet on the highway!
Also has a slight rumble at idle, you can hear the exhaust but it can be drowned out by the blower fan on two.
I was amazed and completely satisfied while driving it home, and best of all no exhaust fumes coming in the vehicle.
My old muffler was blown apart at the seem.

 

[4pointslow]

Muffler

 

[4pointslow]

Then I saw something I did not like.
They did not remove the first restriction where the pipes from the manifolds meet.
I assume it was to difficult a place to get in to and I may not have made myself clear enough that I wanted it started from there.

 

[4pointslow]

Flange for future transmission work (hopefully not needed LOL)
They did install a huge 3 inch flange like I asked.
The muffler sure did discolor on the way home, a couple of WOT runs must have helped with that.

 

[4pointslow]

Sound Clip

 

[2000StreetRod]

Looks good! How was the transition made from the down pipes to achieve the 3 inch dia. muffler inlet?

 

[4pointslow]

Exhaust back pressure test

When I first installed the Cobra m112 supercharger I tested back pressure.
It pinned the gauge and I had not been taking video of it. I did not want to run the test a second time so no video of that and I regret it.
Now it is hitting 8 lbs at WOT which is what Ford says is max for WOT. A lot better than above15-16!
Note that my SnapOn back pressure gauge was reading 1 lb with the engine off.
So it reads 9 in the video but is really 8 since the gauge is out of calibration. LOL

The sound is not my exhaust system, it is the exhaust back pressure tester hose making that noise.
The hose was not leaking either, it just makes that noise and it is loud LOL.

 

[4pointslow]

Looks good! How was the transition made from the down pipes to achieve the 3 inch dia. muffler inlet?

See post 292 and the first picture in post 293
I hope that explains it better than I could.

 

[4pointslow]

I forgot to post the boost went from about 10 to about 8 psi due to the increase in flow through the engine.
I am pleased regardless of the fact that they did not remove the first restriction.

 

[CDW6212R]

Well done, that is a big step in the right direction. I hope it stays at the sound level you want, and it doesn't gain any new rattles etc.

I'm going to do my rear exhaust first too, and then the cat pipes next, working forward. I think you found a muffler that you like the sound of, that's about the hardest part. I'll try my guess and see if it needs anything more.

If so I'll try my hand at making a pair of Helmholtz chambers, just small muffler shaped boxes with an internal "dead" volume inside, 3" inlet and outlets, small enough to go behind each muffler.

 

[CDW6212R]

One other thought, I see the pipe runs above the control arms. I thought some went under the whole rear assembly. Is there room under there to run two 3" pipes, in the 3rd gen or 4th etc?