CatBack Advice V6 Sohc

[Lazzman]

I read several muffler threads on this site and it seems that the consenscous is for the Flowmaster muffler.

My question has to do with a custom Catback system though. The explorer's stock muffler has two inlets and one outlet and the factory tubing is 2 1/4". What is the best upgrade size and configuration for a new catback pipes? I know on other modified vehicles you do want to maintain some back pressure i.e the exhaust pipe size shoule correspond to the engines cubic inches. A system that is to free flowing and does not provide enough back pressure is equally bad.

I think it would be safe to use 2.5" tubing and I am really interested in the dual intlet muffler with the single 3" mandrel bent tubing outlet. Would this provide enough back pressure?

I have a Volant cold air intake and am planning on adding a Bama chips X- Comp soon.

My plans are to use a Flowmaster 50 series SUV muffler with dual inlets to fit the Sohc configuration and either a 2.5" or 3" outlet pipe. I have a custom muffler shop doing the work, so any configuration is possible.

Opinions please.

 

[Skibum1989]

From flowmaster's website:

"What pipe size should I use for a street application?
In general, the following guidelines should be applied for street applications.

2"
tubing
up to 100 hp per pipe

2.25"
tubing
up to 160 hp per pipe

2.5"
tubing
up to 200 hp per pipe

3"
tubing
up to 300 hp per pipe"

http://www.flowmastermufflers.com/faq.html

 

[aldive]

3" pipe is probably too large.

My cat back is all 2 1/2" pipe ising a Flowmaster 70 muffler.

 

[Afboy143]

I have a 50 series dual in/out muffler 2.25 inches to the rear and I noticed some off-the-line loss and more power in the higher speeds. Sometimes I want to go to a single 2.5" pipe out the rear...but love the look of duals. (plus money is low)

 

[Lazzman]

Thanks for the replies. 2.5" it is.

 

[gijoecam]

I'm running the Flowmaster 50-serise SUV/Performance with the dual inlet, 3" outlet. It is adapted down to the OEM tailpipe though.... sounds AWESOME! Don't know if it helped the power at all, but it sounds a TON better than the rotted-out OEM one did.

-Joe

 

[spindlecone]

Use 2.5 in pipe as said above and use 3 inch tips if you want the look, will have no bearing on back pres, thats what I did

 

[gijoecam]

Not to hijack, but what size are the OEM pipes? I never bothered to measure them.... just curious.

-Joe

 

[spindlecone]

Mine were 2.25

 

[94ZebraRanger]

I've got the Flowmaster cat-back it gives good sound with out being too loud. Mine had the rear pipe hanger in the wrong place so I had it rewelded. It now tucks up really nice and tight to the bottom of the quarter panel.
I think it is 2.5"

Tim

 

[cisurfer]

i just measured my inlet and outlet pipes. It looks like 2.25 dual inlet and 2" outlet on 99 sohc X. I ordered a 50 series with the dual inlet and 3 inch outlet and i guess i have to do a new tail pipe. Is 3 inch too big or should i go with 2.5?

 

[jah81592]

i just measured my inlet and outlet pipes. It looks like 2.25 dual inlet and 2" outlet on 99 sohc X. I ordered a 50 series with the dual inlet and 3 inch outlet and i guess i have to do a new tail pipe. Is 3 inch too big or should i go with 2.5?

I used a MAC catback system w/the 3". If all you were going to do is install a exhaust system 3" would probably be too much. But... If your future revolves around the complete complement of bolt on's and possible engine work I would go with the 3" system. Your choice. I prefer MAC, but so many choices and different opinions offer many different products.

 

[Mista808]

I would like to get catback with the 2.5 and 3 inch tip as well. Would they just run it where the stock pipe goes all hidden? I'd personally like to see the tip a lil more..

 

[Lazzman]

Mine finished with a dual inlet SS409 muffler and 2.5" tubing going to a 4" chrome pipe. I had them tuck it up deep nice and high so chrome was the only thing visible. The SS 409 Flows better than the Flowmaster 50 because it is a straight through design with fiberglass packing.

I had to switch mufflers twice before the guy at the shop put on a resonator. With the V6 they come from the factory with a resonator- unless you want to sound like rice you need to get that. A nice 2.5" Pro Flow mounted in the factory position is an excellent choice.

Will post picture.

 

[adarkang]

I used 2.5" piping after the muffler (50 series SUV) and removed the resonater. I noticed a 3 MPG increase in fuel economy with this setup on my truck!

 

[Lazzman]

Yes I noticed about 5 mpg between my intake and exhaust.

I am surprised you do not have any resonance with that muffler, mine was crazy bad from 2200 - 2900rpm.

 

[Ewrencher]

Exhaust ideas

What muffler or exhaust kit do you all like would produce the best result and is there anything I should modify in the ehaust to get the deep tone I'm looking for out of my SOHC engine?