I am considering a catback exhaust system for my 99' F150 5.4L V8 and I am looking at FlowMaster's Force II (dual rear out)system. I was hoping someone might be able to tell me the diameters of both the inlet pipe and the two outlet pipes. I checked FlowMaster's web page, but I could find any info about this. My only real concern about this system is the possibility of losing some low-end torque. If anyone has this system on a 5.4L V8, I would also like to hear any pros and/or cons about it. Thanks for any info on this!

Matt

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99 F150 X-Cab 4x4 SB, 5.4L V8, Deep Wedgewood Blue/Dark Graphite, ORP, 3.73 LS, Tow Pkg, Captain's Chairs, AIRAID, Luvernve Stainless Nerf Bars, Lund Frontrunner bug deflector, Lund Eclipse taillight covers, Lund Eclipse side rear window shades,

Sony Mobile ES CDX-C7850 head unit, Sony Mobile ES XDP-U50D DSP, Sony MDX-65 MiniDisc changer, Rockford Fosgate Punch 600a5 amp, Infinity Kappa 62.1i's in the rear and Kappa 63.1i's in the front, 2 Rockford Fosgate 8" Punch XLC subs under the rear seat in sealed boxes.

Soon to be added: RamAir styled hood to replace my hail-damaged stock hood.

 

According to Flowmaster, they do not make a force II system for the F150. The force II system is a single outlet 3" that fits in stock location and a big block muffler. The American thunder is the dual outlet 2 1/2" outlet set and a 3 chamber 50 series muffler. It may effect the torque of the vehicle but not significantly. I talked to Flowmaster last week and they also do not expect to make a force II system for the F150 unless enough people call and ask why not. I do suggest that you run a K&N filter with your new exhaust. From what I've read is that the drop in filter is not much less restrictive than the hundered and some dollar kit. Just a suggestion. Enjoy your new exhaust, they sound great.

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1999 F150 S.Cab 4x4
Northland Edition,5.4
Off road pkg. Fleetside
Black w/grey int.


[This message has been edited by Bob's F150 (edited 11-09-1999).]

[This message has been edited by Bob's F150 (edited 11-09-1999).]

 

Actually Bob, Flowmaster's latest catalog lists the split rear exit kit (part #17222)and the side exit kit (part # 17226) as a Force II. They have never made an American Thunder kit for the F-150. Every time I call that place, I get a different guy and he tells me something entirely different than the last time I called. Very frustrating. Anyway, what's in a name? I helped a buddy put a similar kit on his Dodge Ram (part# 17179), similar 50 series muffler, same pipe diameters,etc., yet it was called "American Thunder". It sounded sweet, no matter what you call it. They are avoiding creating an American Thunder kit (which would require a 40 series muffler in the F-150) because of the severe interior resonance inside the vehicle, from what I've been told. check out www.flowmastermufflers.com for more info.

By the way, the muffler used in the dual outlet rear kit is #530562, which is a 50 series, SUV-performance muffler. It has a single 3" offset inlet and dual 2-1/2" outlets.

Thanks,
Selva1

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2000 XLT Black Sport, Flareside, 2WD, Ext. Cab, 5.4L Auto. Other factory options: 3.55 LS, Class III tow, 6-way Captains chairs w/CD changer, Remote entry , and Slider window.
Mods: Undercoat, window tint, headlight & tail light covers, removed "Sport" decals, upgraded Triton tailgate emblem, Linex spray-in bedliner, and an ARE LSII lid.
Wish list: Flowmaster duals, K&N FIPK, and a Belltech 3/4 drop.



[This message has been edited by selva1 (edited 11-09-1999).]

 

I too have a 5.4L V8 and I am looking at the same thing - dual out Series 50. I am putting the K&N Kit in today and had called K&N regarding their cat back systems. They told me that they have one out but I haven't been able to find out alot of info. Supposedly they are made by Jardine out of Wyoming and are dynoed for the K&N filter.
Have you already made a purchase?

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TommyRox
99' 5.4L F-150 XLT White

• Towing Package
• Extended Cab
• 3.55 LS
• Kenwood 3011 CD Player
• MTX 2-way speakers
• Keyless Entry
• Ford Bug Deflector

tlmullenix@yahoo.com

[This message has been edited by TommyRox (edited 11-23-1999).]

 

MattT,
I just got my cat-back system this Sat.!!! All the diameters are 2 1/2". I myself have have only the 4.6L-'98. But, I don't feel I have lost any low end torque,a lot better throttle response!! But I can't prove it (I wish I could get my hands on a Dyno!!) Check out this months Peterson's 4 wheel mag-they have dyno measurements and they did an intake, exhaust and chip upgrade on a '99 5.4!!! The Flowmaster is a great system-it fits perfectly (up and over the axle and around the tow package with space to spare!!). It even has a 3rd bracket to support the driver-side exhaust pipe! And the tail pipes are polished stainless steel & slashed 45 deg., and not just a cheap tip!!!
Not only does it LOOK AWESOME but is sounds great too!! It isn't as loud as running without mufflers but it is a hell of a lot better than the stock muffler(How could I NOT resist not starting it up and taking it around the block after we took off the stock muffler!!! I wish it were just a tad louder!! But it was the best $300 spent!!
It took only 2.5 hrs to throw on....of course a couple of minutes to drive around without the mufflers on but it was a pretty easy install. I do recommend that you have a friend over to give you a little hand!! He did come in handy at times!!
I got it from Summit Racing for $291.39 + $6.99 for handling. Free shipping by UPS ground, unless you wanna get it sooner you can pay more for shipping. It took 4 days to Arizona from Ohio. #17222 like selva1 had said!!
If anyone has any questions I am more than happy to answer any!! E-mail:XVR4667_mm@hotmail.com


[This message has been edited by XVR4667 (edited 01-17-2000).]