June 10, 2017
I have owned my 1999 GT since new, and have tried many exhaust systems in that time. These are by far my favorite, and have such a unique sound. If you are looking specifically for the Flowmaster sound these are simply not for you.
(IMPORTANT) I understand there is no "burn in" period for these mufflers, but my own experience and those of others confirms the sound these make when first put on is tame compared what they sounded like after a month or two. So no matter what ANYONE tells you there is in fact some sort of break in period where the sound changes. Most notably they did not have the awesome popping an crackling when downshifting at first, and this took at least a couple of weeks and a few hundred miles of driving to develop.
So no they are not as loud as the Flowmaster 40's inside the car, but outside the car everyone hears you just the same. Best of all when cruising at lower speeds, you can chose to be heard by keeping it in a lower gear and running in that sweet spot around 2000 RPM, or drive in the higher gear keeping it around 1200-1400 save some gas, and arrive in stealth mode so that no one hears your awesomeness until you are right on top of them. On the highway in 5th gear my GT with stock gears is not overly loud right around 55-60 MPH and fine for long trips you can't talk at normal volume and hear the radio. However it turns into pure beast mode between 60-80, it sounds AWESOME, but on long trips at higher speed it could be deemed "annoying" by some.
I want to emphasis these really do have a unique sound that is quite different from the "Flowmaster sound" which ever other muffler seems to emulate. It's admittedly not as menacing as one of the more aggressive Flowmaster series when at idle, and inside the car it's not nearly as loud, but under WOT or when raving it up in the parking lot, the sound is pure bliss and flat out nasty.
If you are one of the people crying this or that is not "loud enough", as if loudness alone were the only measure of how "good" and exhaust note sounds. You should probably be driving a 4 bangger with a hairdryer, no cats, and a coffee can hanging off the back.
If you want the ultimate tone that will not ruin your hearing, and sounds flat out nasty when you rev it or are WOT these are the ticket.
You could probably slap these on in hour or two, but if you are using new flow tubes, and want to cut everything to make the tips flush with your rear bumper. Give yourself a day and have it look like a pro did it.