Exhaust outlet pipe size for V6?

[sk1er17]

I just ordered my flowmaster 50 series and im having it installed on monday. (98 sport, dual in single out. 4.0 SOHC)

1 question though.. what size outlet is everyone running? I was something with a nice tone but not annoyingly loud.

The muffler has a 3" out so i was thinking of having them just bend a 3" pipe all the way back. But i remember one thread saying that was loud and another thread saying it looked un-proportional. Im not worried about it lookin un-proportional because i think my X is worthy of a 3" pipe . but...... what about the sound?

Also, would it be stupid to have them run a 2.5" all the way back and if i don like the sound i can just put a 2.5 to 3" tip on it? Or wouldnt it just sound better to run a 3" back?

Anyone with experience in this..

 

[X~FACTOR]

I think the sound will be good and rumbly. The thing that concerns me is maybe you might lose some low end torque because of the lack of back pressure.

I thought the 50 Flomasters came with 2.5" outlet?

 

[sk1er17]

the one i ordered (only one made for my vehicle) is dual 2.25" IN / 3" center OUT. Part # FLO-524553.

Hmm, i dont want to lose torque.. i tow a 21 foot boat.

 

[Hokie]

don't do a 3" out... I'm thinking of changing to a 2.25" pipe on my Magnaflow to gain a few more ft-lbs (which are nice) at the cost of high rpm HP (which I don't use).

Also, with the SOHC on a Sport, the 3" pipe would probably resonate to all hell. Alec has to run 2 resonators on his 3" setup.

 

[Alec]

On your SOHC I'd put a resonator and a 2.5" tailpipe.

 

[BonesDT]

what are the factory pipe diameters going in and out of the muffler? is it 2.25"?

what diameter out pipe would give the most torque? would it be stock 2.25" or a little larger like 2.5" which a lot of people seem to think is a perfect size.

 

[Alec]

I think 2.25 is good for OHV, 2.5 is good for SOHC. However, with the larger pipes undesired resonance can be an issue, so I recommend a resonator after the muffler with a 2.5" pipe.

 

[sk1er17]

our stock muffler is 2.25" dual in/2.25" single out. The FLO-524553 is 2.25" dual in/ 3" single out.

Good question... thats exactly what i want to know!

 

[BonesDT]

what exactly is resonance? im not worried about loud issues, cuz i kinda want a loud exhaust. but it sounds like resonance is some kind of rackedy vibrating annoying noise, is this true?

 

[sk1er17]

resonance gets annoying.. its a sound that causes bad headaches... kinda like if you were driving on 45" Xterrain tires at their loudest. what "whhhaaaaaaaaaaaa" sound. Basically the sound i dont want.. i want the Rumble.. not the resonance- thats why i bought the 50-series instead of the 40 series.

 

[Hokie]

resonance is the sound waves in the exhaust hitting causing the pipes and the truck and your head/ears/etc. to resonate. it can sometimes feel like a pressure on your ears and it will drown out everything else. some peolple call it a drone, or whatever. But the worst kind of resonance is when your exhaust's resonant frequency happens during your highway cruising RPM's like my magnaflow did before i put on the resonator.

 

[Nate1]

I just had someone drive my SOHC down a straight street a few times at different revvs to show me how my 2.5" with a resonator sounded outside the car... it sounds great BUT since it is a magnaflow... the resonance inside sounds higher than the actual sound of the vehicle even coming towards you, and it is pretty loud. Dynomat fixes the problem alot, I hear... so I may try that next, but after I heard it outside, I am going to keep my magnaflow... its loud and rumbly... burbly... so a 50 flow with 2.5 and a resonator should sound great... but you may even want to go with 2.25"... it could sound better, and you will keep torque loss to a minimum.

 

[sk1er17]

How much torque loss are we talking about here? i thought putting a flowmaster on would give about 10 HP gain. Where does that come in when we talk about torque? I tow a 21 foot boat and would like to add power, not take it away. The sound to me is just an added bonus... i want more power! (but i want it to sound good if im going to have it too )

 

[springtensi0n]

geh, i either have 2.5 or 2.75 from the cat back with a nice 4 inch stainless angle cut tip sitcking out diagonally in right corner... it sounds mean while driving, but at idle it just sounds like a wind tunnel, so im going to assume i have very little back pressure. she goes on the highway though...

 

[rydinhigh]

Originally posted by springtensi0n
geh, i either have 2.5 or 2.75 from the cat back with a nice 4 inch stainless angle cut tip sitcking out diagonally in right corner... it sounds mean while driving, but at idle it just sounds like a wind tunnel, so im going to assume i have very little back pressure. she goes on the highway though...

Bwwahahaha dude he has an explorer not a honda we don't need 4" tips.

Sk1er I have the 2.5" flowmaster cat back with the same muffler and love every minute of it. I do not have a resinator nor would I care for one. It only gets loud above 3,000 rpm's and as for tourque loss well I can still spin the 31" tires.

 

[Alec]

With a properly sized Flowmaster and 2.5" tailpipe on the SOHC torque loss isn't a big issue.

 

[Nate1]

I suppose it is with magnaflows because they are alot more free-flowing than the flowies... but dont get me wrong... its a little torque loss (I can still spin my tires too if I want, thanks) and much better passing power.
-----Nate

 

[BonesDT]

what about a dual setup even if its with 2.25"? is this too much flow?

 

[Nate1]

I see no reason to run duals on a SOHC. I think true duals would be too much flow. If you ran a X pipe and some 50 flowmasters with 2.25" piping, you may get by with good sound and performance... but I know the SOHC is a bit more back-pressure hungry than other Ford engines, so I would watch it.
-----Nate

 

[Alec]

If you go with a dual out muffler I'd go with 2" tailpipes. Some people have been happy with larger, but that's what I recommend.

Overall I still recommend a single though.