Critique my Custom Exhaust, Armada

What I have starting at the front is this.

Factory manifolds with two converters on each bank.

3/8 stainless flanges cut by me.

2.5" Mandrel bend kit from Summit

2017 Mustang mufflers with tips relocated to under behind the passenger rear tire, factory location.  These work better than the original dual center in single center out because they are center in offset outlet, this helps to get the tail pipes over the rear suspension with less bends.

This is a true dual exhaust setup with no crossover or X pipe, there really isn't a good place to put one.

Questions,

Drivers side has a 90 followed by two 45's to get over to the passengers side, are the 45's worth it or should I just use one 90 in place of it?

Muffler placement, options are as shown or I could stagger them opposite of shown with the passenger side closer to the front and drivers side muffler behind it?  Current configuration balances the pipe length to from Cat to muffler.

Based on my time with a Titan adding headers and catback I say it will sound like poo.

 True duals always sound like crap,2 4 cyl engines running badly overlapping each other.

 Get a crossover tube in anyway you can and add a 34" long Helmotz tube as well.....you'll thank me later with zero drone ringing your ears.

 I had lots of compliments on how good my truck sounded,more like a tuned sports car v8 than a truck.

Maybe I can squeeze a crossover in just before the mufflers, may need to go with two 90's from the drivers side to gain room.

I'm keeping all four stock converters, just adding dual pipes after that.  My MPG went up by 1.5 -2 with the current leaks and holes, I'm not going for any sound except quiet.  Current setup is a crush bent 2.25" even with all the leaks and no tail pipe it is quiet.

Armada and Titan folks say that you can't get any rumble unless you delete the rear converters so I'm not expecting it to have any sound.

+1 for adding a crossover so it doesn't sound like two I4s getting into a drunken fistfight I expect any difference between the 90deg bend vs 2x 45s will be very small, it might be worth it if you were trying to squeeze every bit of power from a small engine but not for this.

The lack of a crossover would be a deal breaker for me. I'd stick with the stock exhaust before I ran a V8 without one. 

A crossover would be a deal breaker for me. I like my V8s giving the fender dump sound

In reply to buzzboy :

Thats from the cab,stand on the curb and let someone go full blat blat blat blat past you in it :)

In reply to akylekoz :

The 5.6 has a different firing order then typical V8's,even with stock single outlet exhausts the trucks are pretty raspy.

 Great engines and I loved both of mine,youtube is full of lousy sounding examples though.

 Look forward to hearing a successfull sound clip when your finished

In reply to kevlarcorolla 

I've spent many good hours next to and behind a non crossed over 350 with side pipes. It's my favorite (gas)engine sound. 

Yes to crossover if you can

2x 45 vs 1x 90 won't matter in any significant measurable way.

Thanks all, now I have to make a crossover.  It's ok, I wanted to save the 45's for the trail pipes or racecar anyway.

REV A

I only have 12" from center of the second 90 to a cross member, it will have to go there.   It could go under the cross member so really I have maybe 17", 6 or so is used up by the bend.  The crossover will not be the same distance from each cylinder bank, does that matter?

What about muffler placement, specifically should I put the passenger side forward of the drivers side to equalize the distance from each bank to muffler?

Edit; Last question doesn't make any damn sense, it is best as shown in the first picture.

Why not simply a pc of straight tubing between the banks?

In reply to kevlarcorolla :

Left bank takes a 90 right out of the second converter and runs between the transfer case and gas tank to the passenger side.   So I need two 90's before I get to a place where the pipes are parallel.  Good part of that is the cross over will end up 4" long.

In reply to akylekoz :

Ok,missunderstood.....thought you making the crossover out of 90's somehow.

Some fitting needed yet but crossover added!

My plan is to weld the muffler and crossover as a unit then hang it, from there connect the drivers side.  Passenger side may need a jog to line up with the crossover, this will likely be made from a mandrel U sliced and rotated 180 to get an offset.

kevlarcorolla said:

Based on my time with a Titan adding headers and catback I say it will sound like poo.

 True duals always sound like crap,2 4 cyl engines running badly overlapping each other.

 Get a crossover tube in anyway you can and add a 34" long Helmotz tube as well.....you'll thank me later with zero drone ringing your ears.

 I had lots of compliments on how good my truck sounded,more like a tuned sports car v8 than a truck.

What rpm is 34" Helmholtz tube tuned for?  I run about 2000-2100 on the highway, 3:36 towing gears.

In reply to akylekoz :

My truck had the 4:10 towing pkg gears(1st gen titan and 5 sp auto)and iirc it was about 1700rpm which was light throttle cruising rpm at pretty near all speeds.

 34" was perfect in my case,100% zero droning at any rpm and just smoothed the tones out completely for performance tuned sound.

In reply to kevlarcorolla :

Interesting I didn't think any Nissans got 4:10 gears until 2020, prior to that 2:93 was standard 1700rpm at 70 and 3:36 were tow gears 2000rpm at 70.

Either way if I end up with drone I'll add a tube.

Ignore my first welds, I didn't have the welder set right yet and maybe I suck at miging stainless and my tig is broken.

Plan is to cut these two 180's to make whatever offset I need form the passenger side.

In my head the output from the mufflers would be closer together, I hope there is room for the pipes that far apart.  The stock tailpipe comes out centered and the same height as the dual input tubes.

This is a simplified tail section, likely it will need some more shape, pie cuts may be needed to get around the rear cross member and down to behind the wheel.

Am I doing this right?

I moved the dual 45's to the back, other than small adjustments this should be close.  No more cut U bends for an offset, it's only about 9" from passenger cat to the crossover.

Muffler assembly is heavy, I'm ready to hang them and then fit to the right side collector flange.  Tail pipes are just a guess right now until I get the rest in place.