Has anyone used one of Flowmaster's American Thunder exhausts? They claim that there's little-to-no interior resonance and that they aren't obnoxiously loud. That seems great to me, but I didn't totally trust the marketing. Hopefully one of you has some first hand experience.
EDIT: my dumb ass got Flowmaster's exhaust systems mixed up. What I meant to ask about is the Force II systems. I'm leaving my mistake above so the first responses make sense.
Nothing eh? These systems use the 70-series big block muffler if that helps.
My truck is rather prone to droning, even with the stock and very quiet exhaust there was a resonance about 2000 RPM. When I installed the header, getting rid of the first cat in the process, I went through a number of mufflers trying to get good, but quiet sound and no resonance. I ended up with the 70 series and I love it.
Have a Flowmasterrific Day! It's saying for a reason.... reason..... reason..... rea..... son..... rea.... son..... rea..... son....... rea............. son..............
But sure if you want to believe ad copy. You do you.
In reply to AnthonyGS (Forum Supporter) :
Not trusting ad copy is why I came here. Have you used one of these mufflers?
In reply to thatsnowinnebago :
I drove a car with one of these systems, drone master will never outlive its name I think.
I have an american thunder system on an '88 camaro with a 350. It was great when i was a kid in highschool and never drove more than 20 miles. As an adult, it is not tolerable for longer drives. It sounds fantastic at idle and for short stints. Not so much at 70mph.
I have started installing vibrant performance resonators into most of my cars, and quieter mufflers (still louder than stock, just not as much). Exhaust sound engineering is wildly complicated. Some drone can be muffler, some can be long sections of pipe, some can be harmonics through the body/panels, it goes on and on....
You know what, I'm dumb 
. I meant to ask about the Force II systems, not American Thunder. I should ask a mod to change the title...
https://www.summitracing.com/parts/flo-17135/make/ford/model/f-150/year/1995
Woops, just noticed that request. Updated/Bump.
In reply to sleepyhead the buffalo :
No worries.
Now that the thread title is fixed, I'm gonna bump this one last time to see if anyone here has used one.
AFAIK all flowmaster stuff is chambered. And it's all echo chamberiffic. Never seen a flow master muffler that didn't resonate loudly at a particular rpm.
As an aside note when Ford did the pushrod 5.0 in the Fox, they used chambered mufflers too. Ford used two different sizes though so they didn't resonate at the same natural frequency to reduce drone.
If you really want a Flowmaster system, I'd shop high end audio too and ear plugs. That's just my opinion though.
Yes, they drone, but there's something to be said for the classic sound of a SBF with Flowmasters. I had the 3-chamber ones on one of my Fox bodies, and they weren't too bad. They'd drone at 65mph, so you just had to speed up a bit. 
In reply to AnthonyGS (Forum Supporter) :
The 70-series is chambered like the rest. The interesting part to me is it looks like there's an attempt at a Helmholtz resonator built in to the inlet side of the muffler:
I'm following because I will probably need to replace the system in my Ram and I'm considering Flowmaster, Magnaflow, Gibson, and Summit systems.
After my cat disintegrated, the chamber muffler was too loud ( due to internal rust and a hole in the case). As a budget friendly approach I tried on of these:
I was concerned about it being too loud after it arrived, but it actually isn't bad. It sounds healthy, but not too loud, and I don't get any drone on the highway. It's only been in for a month, so I can't speak to longevity. It is heavy though, so that could be an issue depending on the application.
You'll need to log in to post.
