Hello,

I am thinking about buying the Flowmaster cat-back kit for my 02 Navigator. The kit I am considering includes the 50-Series "SUV" muffler.

Questions:

I've read that the 5.4 liter motor tends to cause a "drone" at ~2000 RPM, resulting in an interior drone at crusing speeds. Does the Flowmaster kit cause ANY interior drone or ANY increased noise at the interior during part-throttle/crusing speeds?

I don't mind increased sound levels outside and under acceration or WOT, but I am only willing to tolerate a very small amount of increased noise at cruising speeds. What are your experiences with the Flowmaster kit?

I know there are other makes such as Gibson, Borla, Dynomax, etc. I would like to consider the Flowmaster system first.

Thanks,
JAMES.

 

I have the 40 series on my 5.4 and it sounds great under acceleration, and it gets quiet when it hits OD, but being a flowmaster it does drone on the inside a little but not bad, I used the rubber undercoating on my truck and it helped a lot. If you want 40 series sound without the drone go with the super 40. I dont like 50 series, but thats just me. Forza Flow makes a muffler that is deeper and quieter then flowmaster. Hope this helps

 

Thanks for your response. Why don't you like the 50-series? Is it too quiet for you or does it have some sort of design flaw? Have you had experience with the 50-series, and if so, does it drone at cruising speeds?

Thanks again,
JAMES.

 

50 series is a great muffler! I just dont like the sound, its a little to quiet for me, I've put several of them on trucks and SUVs before. They are deep and mellow, you really cant hear them that good. If youre looking for a quiet inside then go with the 50series. If your looking for a good louder sound, with a quiet inside go with the super 40, or forza flow. I've heard them all.

People will come to the shop and want to be loud outside and quiet inside, I give them the Forza Flow or 40 series.

 

A buddy of mine had a flow 40 with the pipes out of the back on his 02 supercrew and the drone on the inside was noticable. He ended up changing it for a 50 b/c of it. The 50 didn't sound as loud outside, but the drone was mostly gone.

 

Being a Navigator, I wouldn't think you would want any excess noise.. so I recommend the Ravin z55.. If you wanted louder you could go with a z33.

You can listen to sounds of it here.. on my 5.4 f150.
There are pics of the setup, sounds and a movie..

https://www.f150online.com/forums/sh...hreadid=172627

Use "Save Target As" to get the files.. clicking on them won't work..