I have a 2001 F-150/Super Cab, 4x4, 5.4l V-8.
I am upgrading the exhaust system. I have heard that with the flow master(which my shop recommends) I will lose low end torque. I tow travel trailers and a boat, so can't have that. I heard that Gibson will increase HP and no loss in torque and that Magna flow will increase both. Does anyone have info, and which models should I get?
I will also be replacing the headers, with JBA i think, and adding a superchip with the K&N FIPK.
Thank You, Eric morrow

 

I went with the flowmaster, the people that i talked to liked the quality, What do all the drag cars use, Flowmaster. I used the 50 series becouse its not to loud but a slight rumble. I also went out in front of the right tire like the lightning, when you pass someone, it really gets there attintion. also flowmaster offers more options, size inlets,outlets, noise.



99 F-150
K&N FIPK
Fllowmaster 50

 

I have had Flowmasters on various trucks, both FOrd and Dodge. I every case, there was s slight loss of low end torque...I didn't care, as I don't tow anything, but I think there would be a problem if I did.

On my new Supercrew, I put on the Gibson SS, and I really like it. A little increase in torque and a slight rumble...not loud, but a great sound. Also, the flowmasters always droned in the cab, both the 40 and 50 series....the Gibson minimizes that....


Comparing apples to apples, I would do the Gibson again....

 

If you plan on using your truck as a truck and actually tow and haul stuff, go with the Gibson. It's designed to increase both low end hp and torque.

You have to be carefull when a muffler claims hp and torque increases. It usually means in the HIGH end of the rpm's.

I've got the SS and really feel it increased the low end. As davidzog stated, the SS is quiet, but has a nice rumble to it. No vaccum cleaner sound like the stock unit had!

You may want to research the FIPK mod a bit more. If you want all low end power, this may not give you what you expect. This is just from what I've "heard" on this site, but most people have them with no complaints, so you'll have to decide yourself. Also know that with the chip, you'll have to run premiem fuel, and again, not sure how much low end power that will get you, but there is an entire forum on that subject and a very knowledgable fellow that can answer all your Q's on that topic.

 

I have the Gibson SS and like it. It doesn't offer much sound improvement. During normal driving it's very quiet. When towing a 4000lb boat uphill it gets somewhat louder. Any louder muffler would be annoying in that situation. Of course a 4000lb boat puts quite a load on the 4.6. The performance improvement is noticeable, with better low end. This muffler is a good choice if you do alot of towing.

Cruzer.

 

Gibson SS also and no complaints. I previously had the Flowmaster 40 Series (Delta Flow) with a 3" single out and lost low end. The drone was alittle too much for me. If you decide to go with the Flowmaster, have them mount the muffler further down the truck.

 

I have a Flowmaster 40 series (no delta flow) and I love it. I went to get a 50 series, but it wasn't available. I was afraid the 40 series would be too loud, but I was pleasantly surprised. Sounds just like I had hoped. My exhaust exits the rear, and it has a nice low rumble that I can barely hear inside the truck (which is a good thing), but it is very noticeable outside. I didn't know my truck sounded so good until someone else drove it down the street for me. Also feels like it picked up a little power down low.

No drone here!