I recently purchased a 99 F-150 4x4 sport 4.6
and I am thinking about installing a Flowmaster cat back system and was wondering if anyone has anything to say about it bfore I jump into it?

 

Sugarman~
I had a Flowmaster system installed and have been very pleased with the results(looks, sound, and performance). Also, since I only have the 4.2, you may see even a greater improvement. Hope this helps . . .

 

sugarman-

there really is no need to buy a complete system when just a muffler will do. your stock muffler is the real culprit, not the pipe diameter. 2.5" is plenty for you 4.6l. having said that, i have a '99 5.4l, i had the stock muffler replaced on mine with a flowmaster 3-chamber 50 series muffler (42551?, i believe) and had a stainless steel tip added as well. the results . . . good sound, not too loud, but you know what's under the hood when you get on the gas. at idle there is a nice deep sound and with the windows down, it sounds even better.

steve

 

Yep, the 42551 is the 2.5" 50 Series. And a 2.5" single is plenty big for the 4.2L and 4.6L. And I also just replaced the muffler, but I used a turn-down instead keeping the stock tailpipe.

Danny

 

I love my flowmaster. I put a dual out 2 chamber on my 97 4.6. It sounds great. All I get are comments on it. SO many chevy's are looking for races now. I'm not much faster than them, but just enough to win! I took the truck to be serviced at the ford dealer yesterday and a bunch of salesmen were walking around and saw the 4" chrome tips on the back and were asking me how it sounded. I started it up for them. The look on their face was great, they all loved it. It's not too loud on the highway either, I don't even hear it. It's perfect!

Mike

 

I have a Flowmaster on my 98 4x4 and it's great. Makes the truck run and sound great. It's not too loud, has that nice deep tone.

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Mudder, Black 98 F-150 4x4 0rp 5.4 s/c, bug shield, roll bar,6 KC lights, Manik grill guard, Westin step bars, Flowmaster dual exaust, K/N air filter, 265/75/16 BFG AT/s, American Racing Baja wheels, Ramsey winch and tool box on the way.

 

Mudder
Can you tell me what muffler you have? I am looking for a system for my 5.4l and was wondering what you had. Do you have single or dual outlets? thanks.

 

I think I am going to go with a one chamber flowmaster and dual 3" pipes on mine...Well I will try it first and if it don't work out then I can always try something else


99 F-150 Sport SC SB 4.6 K&N air filter no chip yet but workin on it gotta kick some chevy butt!!!!!


Hey if anyone knows where to get Vinyle stickers cut would yall put "only little boys wear bowties" and "RAM IT UP YOUR A$$"

that is what I am going to put on mine and was just trying to get a national thing started!!!!!!!!!!!!!!!!!

 

I read all of these posts and RAN out and had a flowmaster put on my 97 4x4 4.6. Oh talk about a nice sound! I put the 2 chamber 40series and a new custom bent steel pipe out. I don't know what you mean by mandrell bent but mine doesn't have any wrinkles in the bends. I also kept the pipe's position in front of rear tire. The pipe out is 2 1/2". My husband drove it to chruch today and he could tell there was more "pickup" when shifting gears.

 

Smill:

I have a single chamber with 4 inch dual tips that exit straight out the back. It really is great, only cost me 80 bucks (my dads buddy owns a muffler shop). Good luck to ya.

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Mudder, Black 98 F-150 4x4 0rp 5.4 s/c, bug shield, roll bar,6 KC lights, Manik grill guard, Westin step bars, Flowmaster dual exaust, K/N air filter, 265/75/16 BFG AT/s, American Racing Baja wheels, Ramsey winch and tool box on the way.

 

SMILL
I have a '97 with the 5.4L engine.I bought the Flowmaster cat-back system from Summit Racing.It has a 3-chamber,single inlet/dual outlet.It uses 2 1/2" aluminized pipes coming out that clamp together and exit out the back like duals would.I had 4" chrome tips welded on at a muffler shop.I installed it myself in about an hour or so without a lift. Leave all the clamps loose to get it situated around rearend and hitch(if you have one).Only problem I had was the 4" tips were too close to my hitch,so I had the corner of it trimmed off.It sounds alot better than stock.At idle the 3-chamber is fairly low,but comes alive when you get on it.At highway speeds it sounds good,and with the windows up you can still talk without having to yell.I'd say it is definately worth it.By the way,all my local muffler shops quoted me prices of around $300 using mild steel 2 1/4" pipes.For around $250 I have aluminized 2 1/2".The 4" tips were $50. The new Flowmaster system comes with polished tips that are angle cut(mine was an early model that didn't).

 

Hi KnightS,

I have a '97 4x4 with the 5.4L engine. And, I just ordered the same Flowmaster cat-back system that you installed (pn 17137 I believe). I was wondering, did you have to remove the pipes before the Y (directly after the cats)? Or does the Flowmaster kit begin after the Y. I went with the kit because it seemed so well engineered and add to that a local muffler shop suggested a Flowmaster solution for about $375, so I will save a couple bucks too. I would appreciate any other notable hints you may have to help someone get through the installation. How did you learn about the polished tips on the new systems? I hope the kit I ordered will have the polished tips... How long has your system been installed? Lastly, have you noticed any difference in throttle response or a performance increase? Thanks, Dirk

 

have you guys ever thought about just going 'straight out' (no muffler)? it was suggested to me before i had the glasspack put on. and... is it possible to have true duals on a v6?

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'97 f-150 XLT V6 auto silver reg cab flareside KC Special, tonneau, ground effects, duals. the heartbeat stops here.

 

DirkR
That part number seems correct.As far as the polished tips go,I saw a picture in a Flowmaster newsletter I got in the mail a while back.When I bought my kit it came with straight cut tips that exited right at the bumper(looked too plain).The price at the time through Summit was $245.The picture I saw showed all the same parts I had,except the tips were angle cut and polished.The best way to describe the look is that of a Mustang exhaust.I saw this newer kit about 4 months ago,so yours should have them.Also,the price went up in Summit to $254(probably the cost of the polishing).As for the factory system,I removed it after the Y-pipe at the slip fit that has a U-bolt holding it together.It was a little tough getting off because the U-bolt crimps the two pipes together.I used a Dremel to carefully split just the outer pipe and peeled it back.Do not cut both pipes.The new muffler has a pipe which runs up to the pipe coming from the Y.The pipe from the Y goes inside the pipe from the muffler.If you cut both pipes during removal,the new system probably won't reach.The only other problem I had was with the muffler hangers.Mine didn't line up with the stock hanger,so I had to cut and bend the factory hanger.Without doing this,the pipes coming out of the muffler would rub the underside of the bed as they went over the axle.Cutting and bending brought them down.As I stated before,take your time and leave everything loose.Get it in place and just snug the clamps(tightening will crimp the pipes).I then rocked the bed up and down to listen for rubbing.Mine rubbed on the differential cover-with a little tweaking you can get it to clear.I hope this makes it a little easier.I've had mine about a year and a half.It looks and still sounds great.I'm not sure about power.I added a new chip at the same time,so I can't say which one helped the most.

 

Thanks for the info. I am looking forward to installing the system. A few last questions, then I will make my next post here after I have installed the system. 1. Is your truck a 4x4? 2. What size differential do you have (10 bolt or 12 bolt)? 3. Did you see any mileage gain after mods were installed? Talk to you soon!