WOW!! I've been reading this thread for over an hour and the one thing I've learned for sure about exhaust systems, "ask 20 different people, get 20 different answers".
But here goes anyway....
Interested in a cat back system for my 99 f150 4.6 auto 4x4 sc lb

IN ORDER OF IMPORTANCE:

No DECREASE in gas mileage (hopefully increase).

Noticably improved torque/horsepower

QUIET! (or... on the quiet side)

Dual out the back

Cost (still important even though its last)

I would be interested in any and all opinions

Thank You!

 

Sorry man,

With an exhaust system your gas mileage decreases and of course they are LOUD! Why else would you want an exhaust system if you wanted it quiet?

I have an xcelertor muffler, and my truck is loud but it sucks back on the gas. Yes, it did add some power, but not a real noticeable amount.

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My F-150

• XLT
• Toreador Red
• Super Crew
• 4.6 Liter
• v8
• Xcelerator Muffler
• Dual Exhaust (Y-PIPE)
• 6" Chrome Tips
• Vent Shades
• GTS Headlight Covers
• Rhino Sprayed-In Bedliner
• Flairside
• 20% Window Tint (Front 2 side windows)(Illegal)
• 11" 7% dark tint band on front (Illegal)
• Bugflector
  Pending
• 33" BFGoodwrench All Terain Tires (with rims)(June 2001)
• 3" P.A. Body Lift (June 2001)
• No Muffler (June 2001)

THE BEST TRUCKS ARE BUILT FORD TOUGH

 

 

Sorry man, wrong answer!
it almost NEVER deceases mpg.

 

im going with the single gibson side back as it is just supposed to be a little louder then stock. i don't think i'll get a decrease in gas mileage but might 'cause according to gibson i'll build up or keep my low torque. not any more expensive then other decent systems, but i have the stainless and if you live in a snow bound area, i'd go that way too.

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2001 F-150 4X4 Supercab
XLT 139" WB style side
5.4L V8 3.55 LIMITED SLIP AXLE
MODS:
AIRAID FIPK
SUPERCHIP(FLIP CHIP)
ROLL & LOCK TONNEAU

sitting in garage mods
GIBSON CAT BACK
GIBSON HEADER
REFLEXX COBRA HOOD
STREET SCENE GRILL
HOLLEY THUNDER SUPERCHARGE
ALL TO BE INSTALLED IN 20 DAYS

 

Yep Me thinks your pretty much correct. I have read over all the post in exhaust and exhaust systems about 3 times ( while obtaining many headaches) and have almost come to the conclusion to just go get what you want. I mean do your research and then get a few opinions and then take all of that and make your final decsion. That reminds me I need to make my post so I can get about 20 diferent opinons on the two different systems I might one.

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97 Ford F150 XLT 4wd 4.6L auto, Std cab/Long bed 2 tone royal blue w tan bottom, PW,PL, and PM, captian chairs w/arm rests

Current Mods
K&N Filter
Xact Plug Wires- 8mm
Ventshade side window deflectors,read window deflector, bug guard, headlight and taillight blackouts
custom hand painted Ford emblems on door jamb guards and under hood on plastic intake cover
plastic mud guards
custom 4x4 off road graphics
Ford hitch cover and license plate frame
Custom carpet liner (protects factory carpet)
Slyvania Cool Blue Headlight and fog lamp bulbs
Pioneer 6 disc changer
Whistler 1650 radar detector
oh yeah, one custom dent and scratch from a deer the night before deer season

 

See what I mean!

Here is my take on what I have read so far not only in these few replies but everything else I've read on this subject:

The primary reason anyone would go with one of these systems would be the sound quality and appearance.

Second, would be for performance because from what I've read returns can be and are negligable.

Third, there is a good chance you will not see any improvement in gas mileage and possibly a reduction.

And finally, they're expensive, so from a dollar for dollar return on your investment, (gas savings, etc.) there isn't one.

Am I basically correct? Like to hear from you.
Thanks

 

2dollarsteak... a higher-flow exhaust INCREASES your gas mileage. This is due to the less restrictive muffler(s) allowing the engine to push the air through with less effort. I've got a Flowmaster stage 50 dual rear exhaust and a K&N cold air induction and my highway milage went from the stock 16mpg to 18.5. Mind you that this is as long as I keep my foot out of it, which is where I assume that peoples milage goes to the crapper... its just TOO gratifying to punch it and hear that rumble, and then there's the hiss of the cold air induction when you let off. <insert grunt here>
T

 

Well i have had Borla and Flowmaster catbacks and i now have straightpipes. With the borla and flowmaster catbacks, my mpg increased very slightly (but still noticeable). power at higher rpm range was also increased. both catbacks i chose, however, had a low rumble to them so you probably wont enjoy it since you want it quiet. If i were you, i would look into flowmasters 70 series mufflers. http://www.flowmastermufflers.com/fm...PerfMuff5.html . slightly louder than stock, but it will give you good gains and its still the quietest muffler that flowmaster provides. good luck!

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1989 F-150 XLT Lariat: 2WD 302 5spd[*]Performance Accessories 3" Body Lift[*]33x12.50.15 BFG A/T's on 15x10 AR Rims[*]Rancho Steering Stabilizer[*]Rancho RS 5000 Shocks[*]K&N Air Filter[*]Gutted Cats with Straight Pipes For Now...

Go Full Speed or Go Home!

 

The "boys" in the local shop I frequent for mechanical work, advice and the occassional just-before-closing Bass Ale, call them "Flowcrappers". Their disdain for Flows is downright chilling. I don't agree or disagree. The boys don't like how they're made. I can't speak to that either. When I asked what I should consider, they said "Borla or Gibson". I wanted a system that was engineered for some increased power, and didn't add a lot of noise. I chose Borla, and I'm very happy. It has a pleasing, low burbling warble as you leave the light, but does not drone. At WOT, I think the engine is noisier. I'll have to sit in the bed sometime for further research. My MPG increased slightly. I did not lose any low end torque. And I very definately have more power.....Power to pass with greater ease, in particular.

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01 Black SuperCrew; Airaid, Borla Split Rear, Line-X, Matched Tint windows. Black. Black. All Black.
-------------------
Blaupunkt "Munchen" HU; JL Audio Stealthbox, DiamondAudio components, RF and Kicker amps

 

Mine hurts too; bumped it 3 times, yesterday, while installng an in-tank fuel pump...using one of our old low-rise lifts.

<eyes @@ rolling>

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2000 F-150 Lariat

4.6 Liter

3.55 Limited Slip

Dynomax UltraFlow cat-back w/ single 3"

K&N Gen II FIPK

 

Sundog7- The Flowmasters do have relatively low flow; so do many aftermarket mufflers. They/many flow under 400cfms. This is approximately twice the OEM garbage can, so there is a improvement. Other mufflers flow 2 to 5 times that much. Although high flow is not good in all applications, those that need high flow can do much better than 400cfms. This becomes much more important when breathing through one muffler, with high HP, superchargers, etc.

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2000 F-150 XL, RC, LB, 5.4L, 4R70W, 4.10LS,
Class III tow, Payload #3, & Convenience pkgs.,
4-wheel disc/ABS, Chestnut/Parchment 40/60,
Ford bedliner w/Paintsaver & gas/wheel/spare locks,
K&N F.I.P.K. w/Outwears pre-filter, Superchip,
Dynomax ultra-flow welded 3" cat-back w/ 3" Y-pipe,
Hellwig front & rear anti-sway bars, Rancho RS 9000s,
Pirelli Scorpion Zero 275/60/16s, Mobil 1, K&N oil filter.

 

I own a borla system(dual out the back). Even with running a supercharger it's pretty quiet compared to other catbacks.

 

well, with dual out the back and a small V8, stick with 2.5 inch pipes after the muffler. that will retain the low end.

borla is really quiet and mellow. rear exit gibson is louder than the side exits(execpt super truck). if you get gibson, you would like the side exit for lower noise. but you want rear exit so......

ussually you wont see big power gains with just one upgrade. expect more collective gains if you do intake, exhaust,chip, etc. all together they add extra power than alone. get what i am saying?