4.6 Exhaust Question?

[wagoner2]

I have done some digging and have not found a thread that will answer my questions. What I want to know is if someone has cut off the exhaust on a 4.6 at or right below the manifolds and run true duals with side exits right in front of the back tires? I also would like to know if you need to or if there is any advantage to putting in an "X" pipe? If someone has done this or something simalar Pics would be great. I am planing to go with a catless true dual setup shortly and need to know if there is anything to watch out for. Thanks!

 

[CALDWELL]

idk of anyone with that exhaust exit location but it would look cool !!


are you doin a full dual exhaust headers and all ???

 

[Cozmik]

I'm interested in the same thing. Will be following this thread.

 

[wagoner2]

I am going to do the exhaust first, Headers second. Not sure of the options on headers at this point, need to do some more looking into. I am just appauled at how restrictive the stock exhaust seems to be. Do you know how restrictive the stock manifolds are? Does anyone port them or do you just go with headers?

 

[CALDWELL]

from what i have read... the factory manifolds are actually flow pretty good so thats not your issue i think...


if your not fimiliar with your exhaust set up...

you have 2 CATS located on your Y-PIPE with sensors right behind them... then right after u pass the Y-PIPE you have a massive RESONATOR followed by a giant MUFFLER, then piping goes over your driver side rear axle and out the back... plus when your Exhaust piping is only 2.25''s... your not flowing the exhaust very effectively...

 

[Cozmik]

It has been suggested to cut off the pipe just past the cats and then run 2.5" pipe with a good muffler. Supposedly you get nice gains and good sound. Plus the resonator and huge muffler are gone saving a few pounds of weight.

 

[wagoner2]

Well knowing now that the manifolds are not overly restrictive I am going to cut off just before the cats and run 2.5" to 3" out the sides with some bullet style mufflers. I am going catless because I hate them and don't have to have them. I will just weld bungs back in for the O2's.

I have a weld in Flowmaster now, I cut off the muffler and resinator and put in a 40 series FM. It sounds ok, I am more intrested in opening up the exhaust and getting better sound, better preformance, and better mpg's. Not building a race car just a better preforming truck.

 

[zerodevil]

with the 4.6L, headers are worth the money if you get the stainless steel ones(the other ones just stay looking pretty longer), next to my tune...headers were my biggest improvement(you lose a little low end toruqe, but you get it back 2-3 fold in the high rpms)! If i were you, i wouldnt bother with an X pipe...and just go for a true dual system...it would give it a real muscle sound...you could probably have your exhaust specialist make your Y-pipe into an H pype if you realy wanted to, which would serve the same purpose(equilizing gas pressure in both tubes to make each make noise at the same time...true duals will flow better though).

 

[CALDWELL]

you said you wanna cut the Y-PIPE before the CATS... does your state check for emissions ???? and i guess you wont be throwing a code if you have the fake 02 sensors in there...


I have a v6, but my current setup starts at the end of my Y-PIPE... where i dropped my resonator and installed a FM Delta 40 and ran 2.5'' pipe to a 3'' tip...

i would love to go true duals, but i would lose way to much back pressure...

 

[zerodevil]

oh...and somthing to watch out for...exiting out of the right side of the vehicle infront of the tire would NOT be smart...as that would put the pipe with in inches of the gas tank(which is made of plastic mind you)...i would venture that it wouldnt be smart to try that w/o some custom heat sheilding...out of the back is deffinately dooable though

and the V8 explorers come standard with 2.5 inch piping.

 

[CALDWELL]

thanks zerodevil for the correction... on the factory pipe sizing...

 

[wagoner2]

oh...and somthing to watch out for...exiting out of the right side of the vehicle infront of the tire would NOT be smart...as that would put the pipe with in inches of the gas tank(which is made of plastic mind you)...i would venture that it wouldnt be smart to try that w/o some custom heat sheilding...out of the back is deffinately dooable though

and the V8 explorers come standard with 2.5 inch piping.

Didn't know the gas tank was on the side, thanks for the Heads up. Will come up with a different plan then, maybe out the back with an angle instead of strait out. Since it is already 2.5" I will probably stick with that. I am looking at doing it early next week, so if anyone has any other info chime in now...

 

[Cozmik]

oh...and somthing to watch out for...exiting out of the right side of the vehicle infront of the tire would NOT be smart...as that would put the pipe with in inches of the gas tank(which is made of plastic mind you)...i would venture that it wouldnt be smart to try that w/o some custom heat sheilding...out of the back is deffinately dooable though

and the V8 explorers come standard with 2.5 inch piping.

When I had my Magnaflow put in it was 2.25 in/out. I would be happy if I had 2.5".

 

[macknos94]

if your still thinking about doing it infront of the tires you better lift that thing up because of the low frame rails. i had true duals made with a dual in dual out setup but i'm waiting to get my thru the bumper tips installed

 

[Rofocowboy84]

I've spent the last few days trying to figure out a nice setup that won't cost me an arm and a leg. From what I've heard, an X-pipe is the way to go for performance, instead of just straight duals? My goal is this:



I'm going to get with my exhaust guy on Monday probably and see what we can do. Just like the OP, right now I'm probably just going to do manifold-back, two high-flow cats (think that's all we need, I have emissions here...and can anyone suggest a manufacturer?), x-pipe built by the shop, dual JBA mufflers, and then pipes going straight out the back, no fancy tips or anything.

 

[wagoner2]

if your still thinking about doing it infront of the tires you better lift that thing up because of the low frame rails. i had true duals made with a dual in dual out setup but i'm waiting to get my thru the bumper tips installed

Putting 3"/2.5" RB lift on and 265/70's next week as well. Will that be enough clearance?

 

[wagoner2]

I've spent the last few days trying to figure out a nice setup that won't cost me an arm and a leg. From what I've heard, an X-pipe is the way to go for performance, instead of just straight duals? My goal is this:

http://www.youtube.com/watch?v=GYk1nGLSAFk

I'm going to get with my exhaust guy on Monday probably and see what we can do. Just like the OP, right now I'm probably just going to do manifold-back, two high-flow cats (think that's all we need, I have emissions here...and can anyone suggest a manufacturer?), x-pipe built by the shop, dual JBA mufflers, and then pipes going straight out the back, no fancy tips or anything.

That sounds great! I do not have to have cats so they are not going on. I may go with an x pipe or might not. I guess it depends on what my exhaust guy says....

 

[Limited02]

An X or H pipe will even out the sound a little bit and one of them helps with torque. I personally don't like the sound of true duals because I like that "smooth" sound. I can say that exiting your exhuast in front of the rear tires will be VERY loud. I originally put a 40 series with dumps on and could not stand it. So I went with 70 series and couldn't be happier.

When the exhaust meets just before the resonator, it's 3"s. I am pretty sure that NO explorer/mounty had a stock 2.5" exhaust all the way out the back.(mine didn't) If a 3" pipe will fit through the rear IRS, then I think you would be happier with removing all the cats and running a single 3" through a Super 44 FM with a 3.5" tip turned behind the rear tire. It will flow more than enough and sound VERY good without being annoying.

Whatever you decide, make a before and after soundclip!

 

[1_v8_merc]

Wow, i assumed all v8's had 2.5 " piping.

****....even my v6 mustang has 2.5" True Duals, although it's custom.
I didnt really lose any noticable back pressure.


Now that i think about it, the stock v8 SUV's DO look like they only have 2.25" piping.
Damn, i bet you could get some killer high end flow if you ran a custom 2.50" Dual setup with some Flowmaster 40's.


Damnit, now im not happy with my exhaust setup, i want ####ing 2.5's now.....****!
2.25" is pathetic for a v8, even a small one like the 4.6L.


And my muffler guy got locked up or had to shut down shop, so now im SOL and need a new muffler guy.

 

[Rofocowboy84]

Wow, i assumed all v8's had 2.5 " piping.

****....even my v6 mustang has 2.5" True Duals, although it's custom.
I didnt really lose any noticable back pressure.

I have a question about that. I've heard both sides of the story, that your engine needs some backpressure, but also that the more flow you can get the better. So, which is it?