[Buddur]

So I'm sitting at a red light yesterday and in front of me was a newer model Forester. I noticed it had two mufflers, and I couldn't help but wonder "Why does it have two mufflers instead on one?".

 

[vintage42]

Two likely reasons:
1. Size and fit. The single pre-2009 muffler is huge. Maybe it would not have fitted up under one side, but instead hung down, looking bad and affecting departure angle. Two smaller mufflers tuck up under the new body nicely.
2. Cosmetics. Dual exhausts look better.

 

[sicko]

Subaru stresses that their symmetrical AWD system is better than the competition's AWD system, and that their system's symmetry aids in their performance. Now they get to have a symmetrical exhaust system too

 

[Snoshado]

Subaru stresses that their symmetrical AWD system is better than the competition's AWD system, and that their system's symmetry aids in their performance. Now they get to have a symmetrical exhaust system too

This is exactly why. :biggrin:

 

[frogstar7055]

Symmetrical exhaust system,now that's funny.

 

[2.5x_sleeper]

My guess is that it's entirely cosmetic. It does balance the rear, but strangley enough, Subaru choose to leave the muffler cans hanging low & very visible? Some members have painted them black & they look so much better!

Bobby...

My MODding Journal

 

[JBX]

Subaru stresses that their symmetrical AWD system is better than the competition's AWD system, and that their system's symmetry aids in their performance. Now they get to have a symmetrical exhaust system too

I'm thinking the 2009's and up should have at least a half-dozen or so symmetrical dual exhaust system decals and badges proudly attesting to that fact. :biggrin:

 

[Justforfun]

Does anyone know if its a true dual exhaust?

 

[LOUROK]

Subaru stresses that their symmetrical AWD system is better than the competition's AWD system, and that their system's symmetry aids in their performance. Now they get to have a symmetrical exhaust system too

I like that answer.

My buddy gives me crap all the time about my forester having dual exhaust. He says its ricer and stupid. If you saw his acura, thats a bit rice. My Forester still looks better then his Mazdaspeed 3 i think. And my sentra is still faster then his dsm so i could care less about what he has to say about my foresters exhaust lol. I love the way it looks.

 

[el Fox beSTIal]

^than than than please !!!

 

[2.5x_sleeper]

Does anyone know if its a true dual exhaust?

To me, a true dual exhaust runs dual all the way from the engine. On the Forester, it's a single pipe, which splits to the 2 mufflers in the rear. My simple answer would be no. :wink:

Bobby...

My MODding Journal

 

[funkymonkey1002]

Does anyone know if its a true dual exhaust?

Not at all, it splits just before the mufflers.

They did it because the competition was doing it and people who don't know about cars want dual exhausts.

 

[ferret]

I replied to an earlier thread about this, back when the 2005 Outbacks came out, Subaru said they used Dual Exhaust for a reason given earlier in this thread, Ground Clearance. 2 Smaller mufflers were easier to fit under the vehicle than 1 large one.

Now they have recanted ...... from 2005-2009, the Legacy/Outback was dual exhaust. for 2010, they are back to single.

Go figure !!!!

 

[damu0703]

"Why does it have two mufflers instead on one?".

....because my mom "said so". :raspberry:

 

[vintage42]

My guess is that it's entirely cosmetic. It does balance the rear, but strangley enough, Subaru choose to leave the muffler cans hanging low & very visible?...

The 2008-back muffler is 9.5" high and 10" wide and 17 inches long. It is a rounded box, almost as high as wide. The 2009-on muffler looks oval and shorter. I don't think there is enough room for the old box muffler to fit under one side of the new body.

Can 2009-on mufflers be hung any higher? If so, the tail pipes would have to emerge higher, requiring bigger cut outs in the bumper.

Does anyone know if its a true dual exhaust?

You can tell just by looking under the rear. The single pipe is split by a Wye to go to each muffler.
There are no true dual exhausts these days except perhaps on some muscle cars and muscle trucks. It requires two catalytic converters.

Rear drive V-engine and Boxer-engine vehicles lend themselves to true dual exhausts, where each bank of cylinders has its own path straight out. But very few such vehicles do.

True duals are possible on rear drive inline engines, but require a split manifold, like the old Pontiac OHC Six, and the present twin turbo BMW Six.

All the "dual exhausts" you see on new cars are "pseudo duals" because these cars are either inline 4 (like Miata) or they are transverse 4 (Nissan Altima) and these fours cannot split the manifold. Or they are transverse 6 (too many to name) or transverse 8 (Lincoln Continental) that must gather the front manifold into the rear manifold and then split the system after the converter.

All the dual-exhaust Subarus gather the left manifold into the right one. So they are all "pseudo duals", even though the boxer cylinder layout is perfect for true duals.

 

[stan_t]

My guess would be to make the car quieter, but my car was super quiet as-is when stock.

Stan

 

[vintage42]

My guess would be to make the car quieter...

Correct: to keep the car quiet when there was no longer enough room for one large muffler.

 

[The Black Box]

Pretty sure it's for packaging reasons with the redesigned rear suspension.

 

[steamloco76]

Subaru choose to leave the muffler cans hanging low & very visible? Some members have painted them black & they look so much better!

Bobby...

Low for sure-I now have one can tucked up about an inch higher courtesy of a stump in the mud. Took off the stainless tips I installed and painted the cans flat black- now you can't see the difference in height.

 

[stevemac829]

Low for sure-I now have one can tucked up about an inch higher courtesy of a stump in the mud. Took off the stainless tips I installed and painted the cans flat black- now you can't see the difference in height.

Hmm...be careful about that. With symmetrical dual exhaust system, I believe we are allowed only a 1/4" difference in the height of each muffler, as measured from the bottom of the rear diff case. :biggrin:
Steve
09 2.5X AT