4.0 Exhaust Clip Thread !

[Explorer Power]

I had the same dillema. Quite honestly, I wouldnt run true duals. Even though it sounds good, out 4.0 motors hate it. This is why I built myself an off-road Y pipe 2.5" mandrel bent throughout and ran it to a single muffler then a single 2.5" pipe out the rear. I had dual before this (not true, had a dual in/dual out muffler) and low end torque suffered from this. Going back to a single 2.5" out the rear made it better. You can also run a "dummy" pipe and real pipe if you're going for the look? lol. Anyway, how did you delete your rear 02's? I used to have a tune to delete mine, but I got rid of it due to it needing premium and now my check engine sits on. I bought 02 sims but cannot figure out how to install. Im curious how you did it. Let me know

The O2 sensors where already deleted when i bought the truck..
I think they simulated them in some way yes.

yes single pipe works the best for low end torque, did you gain torque over the stock exhaust?

But i would like dual pipes in the back and as much torque as possible (at least more than stock).

I have made some set ups..
tell me what you guys think...

Stock setup:

Setup 1:

Setup 2:

Setup 3:

 

[Afboy143]

Im curious as to why you want to run 4 mufflers?? Free flow mufflers, I know you said they are custom built but are they resonators or what? Im not understanding the logic behind 4 mufflers

 

[manaen]

Wow man your drawing are impressive. You must do CAD for a living... But I think I see what your problem is. The 8" wheels are going to really cause gear ratio problems. And that big block motor may be a bit nose heavy... sorry couldn't resists...

Seriously why would you make those mufflers? you know you can purchase the exact same thing for like 20 bucks at almost any autoparts store. Dynomax makes some that are great like these

 

[hunterdan]

Why use 4 mufflers when you can get 1 to do what you want? If you want duals, use a dual inlet, dual outlet muffler to save space, and it will also help to keep the exhaust balanced, similar to an x or h pipe. Here is a good example at a good price:
http://www.summitracing.com/parts/JEX-FB4554/
Or go with a dual inlet, single outlet muffler like the cherrybomb Vortex. Thats what I did with my frontier. Its a reversible muffler so it flows both ways with out affecting performance. Plus, this muffler is already proven to sound good on the 4.0 SOHC.
http://www.cherrybomb.com/products/vortex Part number 88107 for dual in, single out, or 88115 for a dual, dual muffler.
I know you said you really want duals, but its very hard to do on an explorer, and its more expensive as well.

Dan

 

[Explorer Power]

I live in the Netherlands, so i can't buy those mufflers over here.
Tried to get a vortex muffler but that wasnt do-able.
And shipping them is a hell and cost a lot of $$..
Customs are idiots over here, my headlights and intake are at the customs office for months now, because they don't believe the price on the box.. They probably let my pay some big taxes over it too.

So i had a company make some mufflers for me.

This is a comparable muffler:
http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=8273

About the same except my in/outlet is 2,1 inch.
(oh and mine where cheaper also

I had them make 4 of them. The idea was to use them in the true duals.
So that i would have 2 mufflers per exhaust pipe.
2 of them where the original muffler is now.
And 2 of them at the very end of the pipe. (was told that this produces the best sound).

So now i have 4 of these mufflers sitting in my shed and still want to use these in my exhaust if possible.
So i want an exhaust that produces as much torque (and hp) as possible.
While still having dual endpipes.

Thanks for your reply's

 

[Shen2187]

Glass-pack's are known to flow great. However, with four of them, on a full 2.5" system, and assuming the stock catalytic's, you probably aren't going to hear much, or feel much difference.

 

[wrigley_1285]

i have a chery bomb glasspack on my truck and i don't think there's that much of a difference over stock. i think a different muffler like a cherry bomb pro series or a flowmaster or thrush two chamber would produce a much better tone. it might even be a little louder

 

[manaen]

i have a chery bomb glasspack on my truck and i don't think there's that much of a difference over stock. i think a different muffler like a cherry bomb pro series or a flowmaster or thrush two chamber would produce a much better tone. it might even be a little louder

did you remove the resonator? they are very restrictive and remove a lot of noise. In fact I would almost say that removing the resonator from my truck made more difference then anything else. Mine restricted down to about 1 1/2" in the middle with an expansion chamber.

The downside of removing the resonator is the increase cabin noise. But there are ways to remedy that as well.

 

[Shen2187]

did you remove the resonator? they are very restrictive and remove a lot of noise. In fact I would almost say that removing the resonator from my truck made more difference then anything else. Mine restricted down to about 1 1/2" in the middle with an expansion chamber.

The downside of removing the resonator is the increase cabin noise. But there are ways to remedy that as well.

Very true. The cat's are also very restrictive. I recommend replacing them with a high flow unit. I removed mine which I now regret a little because I'm either going to have to buy a new one, or register the truck outside city limits. It's still got to go through DEQ one more time

 

[wrigley_1285]

did you remove the resonator? they are very restrictive and remove a lot of noise. In fact I would almost say that removing the resonator from my truck made more difference then anything else. Mine restricted down to about 1 1/2" in the middle with an expansion chamber.

The downside of removing the resonator is the increase cabin noise. But there are ways to remedy that as well.

all i did was replace the factory muffler with a glass pack

 

[Explorer Power]

Very true. The cat's are also very restrictive. I recommend replacing them with a high flow unit. I removed mine which I now regret a little because I'm either going to have to buy a new one, or register the truck outside city limits. It's still got to go through DEQ one more time

Did you gain torque and horsepower when you removed the cat's?

 

[Shen2187]

I can't give proof but, yeah it does feel like it has more power and torque. The throttle response is amazing too. It feels like it did before I put 33's on but with more throttle response. I guess I just can't say it enough. Throttle response... Lol.

 

[Explorer Power]

I was thinking about how to solve the problem with losing torque when you go duals.
If you Y the pipe's into a single 2,5" pipe after the front cat's and then Y it back to dual 2,25" tailpipes right before the rear axle.
Would this solve the problem..?

 

[hunterdan]

Not sure how that would work out, but I'm going to assume it would be similar in results to running a single in, dual out muffler. Finding the proper pipe diameter is crucial, especially with the duals. On my frontier, dual 2.25" pipes was just perfect for me, gained both on the top and low end, but my Frontier makes significantly more power. If you really want to go with duals, I would say to go with 2" pipe out the back. If you notice a loss of low end torque, wrap the system with header wrap from the after cat pipes back to the tips. The header wrap will help to keep the exhaust gases hot, and moving quickly. Can't guarantee that the wrap will restore all your lost low end torque, but it should help. Although another option is a high temp coating like they dip headers in.

Dan

 

[Shen2187]

I was thinking about how to solve the problem with losing torque when you go duals.
If you Y the pipe's into a single 2,5" pipe after the front cat's and then Y it back to dual 2,25" tailpipes right before the rear axle.
Would this solve the problem..?

That is why they make these. http://www.pypesexhaust.com/xpipes.html

 

[Explorer Power]

Shen2187:
Wouldn't a H-pipe be better?

hunterdan:
Thanks for the tips, exhaust wrap has past my mind before too.


I was thinking about replacing the front cat's with a pair of single mufflers (small freeflow mufflers). Then Y the pipes into a single 2,5" pipe, and run this to the rear axle (couple feet of pipe) (now i would basically have a single 2,5 inch exhaust..). Then split them up again with another Y piece into 2 2,25 inch tailpipes and end with a pair of those same small mufflers (to take away some more of the high frequency popping noise (keep it nice and low tone)) and a pair of nice stainless exhaust tips.

Was hoping this increases my torque over stock..

 

[Shen2187]

H-pipe or X-pipe, doesn't matter. The performance difference is trivial at best, for the v6 anyway. They just sound a little different.

 

[Elessar65]

Very true. The cat's are also very restrictive. I recommend replacing them with a high flow unit.

Modern catalytic converters aren't very restrictive at all, unless they are plugged, and replacing them with high flow units won't really give you a performance boost. It will change the sound a lot though.

 

[Shen2187]

Modern catalytic converters aren't very restrictive at all, unless they are plugged, and replacing them with high flow units won't really give you a performance boost. It will change the sound a lot though.

My explorer is the newest vehicle I've ever worked on so, When I think Catalytic, I think BRICK. You are most likely right though.

 

[Elessar65]

Yeah, a lot of people think that way because when cats were first introduced they were bricks, lol. They do have some restriction obviously, but on a SOHC motor they keep some back pressure, which our motors like. Replacing it with like a Magnaflow cat will gain you like 1/20 of a hp, lol.