3" exhaust for 4.7? - Jeep Commander Forums: Jeep Commander Forum
Exhaust Questions or advice about exhaust systems? This is the place...

 
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post #1 of 5 (permalink) Old 08-29-2009, 09:25 AM Thread Starter
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3" exhaust for 4.7?

I need some opinions on bumping up the pipe size on my exhaust.

I can get the Magnaflow 2.5" muffler and tip for around $130 shipped and do the install at work. Question is, would it be worth it to bump up the pipe size from the flange back to 3"? It's about $20 more to get the 3" muffler and tip, once again install and piping at work. Any performance gains/drawbacks? I want it a little more free-flowing, but don't want to loose much torque.

Has anyone noticed any MPG changes with a muffler swap? (besides having your foot to the floor all the time)

Thanks for any input.

'06 Blacked out, 4.7, 2" RoughCountry lift, SpiderTrax 1.5" spacers, 255/75/17 BFG Mud Terrain, Blacked out and cleared stock rims, Tinted turns and tails, LED interior lighting, Garmin GPS, stealth holster.
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post #2 of 5 (permalink) Old 08-29-2009, 10:59 AM
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I don't know about the 3" but I did get a MPG increase with the CAI AND new muffler and dual out exhaust.

06 Sport-4.7L with QT2

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post #3 of 5 (permalink) Old 08-29-2009, 11:21 AM
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Unless you did a 3" tailpipe as well, I can't imagine that it would make any difference. Going 3" from the flange to tailpipe would probably drop some low end torque.

'06 White Sport:4x4,4.7L, K&N CAI,Flowtech Terminator muffler,Flashpaq,OME HD lift,RRO UCA,20" GF-X wheels 275/55-20 Nitto Terra Grappler tires,rear grab handles,tinted tails,front hooks.
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post #4 of 5 (permalink) Old 09-19-2009, 09:48 AM
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I would just stick with 2.5 inch exhaust.




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post #5 of 5 (permalink) Old 10-11-2009, 12:06 PM
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A mandrel bent 2.5" is probably you best bet to gain efficiency without losing too much velocity(TQ). You can order a U-bend and a J bend and a straight section and make your own high flow 2.5"....prob about 150.00 worth of materials if you can cut and weld yourself.
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