I finally installed the Flowmasters this past weekend. Install was a pretty easy (even though I didn't have the 13mm and 15mm combo wrenches) using sockets and an adjustable cresent wrench.

The best part was when I had my wife fire up the car with the stock muffler off, before installing the new ones :drool: . I shouldn't have done that....now I don't want mufflers at all! Sounds like a (NASCAR) stock car.

But anyway, here are the issues I have now:
1) The driver side is no where near center. In fact it touches the right side of the bumper cutout. I'm going to try to loosen up everything and readjust, maybe try bending a bracket or two. Any tips, tricks, or suggestions? Right (passenger) side is nearly perfect.
2) I was under the impression there wasn't any drone with the Americn Thunder mufflers? I have a low deep loud moan between 1500 and 2000 rpm, under light/moderate acceleration, especially noticable in 4th and 5th gears (std. tranny). Everyone else hear this too? Anyone have an idea if a CAI and/or tune will change this (due to a change in air flow thru the engine/exhaust)?

Aside from the drone, which I may get use to, the look and sound is great!

Let me know what you guys are noticing.

Thanks,
Jim

you will need to adjust the hanger on the drivers side muffler. i pulled the muffler adjusted the hanger & reinstalled it. make sure that your clamps are real tight if they are loose you will get a vibration. the drone was almost eliminated when i installed my cai.

i have the K&N aircharger, Man did it give my flowmasters a louder and more throatier sound, the droan dissapears as the mufflers break in. I've had it for about 3 months now and the drone has dissapeared and it was not as bad as it was when i first got them, but I've gotten used to the drone, not that bad now....

Thanks guys for the info!

So the drone may take a couple of weeks/months to lessen, maybe a 1,000 miles??

Maverick, did you get a tune with your K&N CAI? From what I gather, the CAI is good for 12-14hp alone, then a tune is good for an add'l 12-14hp. Sound right to everyone? IF so this is a neat setup, you can purchase in stages if you want.

Anyone with the MAC CAI notice the same results (less drone). I'm looking at the MAC due to the low price and claims of equal performance (although it may be risky to run it w/o a tune).

Decisions, decisions....

I have Flowmasters, and my drone actually has gotten louder and deeper since they were new. I personally like the deep throaty roar they put out when it drones. Makes me feel like I am behind the wheel of 1970 big block 428 Cobra Jet Mustang!!

No, I am just running the K&N with no tune and hydrocarbon trap in. I am not taking the route of a computer reflasher with a custom tune. I am going to try and experiment with the alternate route of the JET Module Chip. I've had them in the past and they have been great with their Hp/Tq Output. It says an intake and exhaust is recommended. So I am going to see what kind of results I receive with this device.....

being that the flowmaster mufflers are chambered i do not think there is much change in them. if anything you get use to the drone or adjust your shifting to eliminate it.

I don't know who mislead you about Flowmaster mufflers but in the industry they are the worst for the 2000 RPM drone, especially during freeway driving. If you can't live with it then look to sell them while they are still new looking and clean.

they are not a 40 series muffler
they were designed for the 05 gt
they do not drone @ 2000 rpm
they will drone when you are in to high of a gear & are loading your engine.
since i added my cai the drone has almost disappeared

And you do figure out how to shift/drive around the drone.

it is easy
more rpm
if you are hearing the drone drop into a lower gear

Gettin Good and bad input on these on a few other Mustang forums also.
I guess everyones ear is different.

Ive been debating the SLP Power Flows or the American Thunder.
I Like the slighty larger 4" pipes on the Americans, but if drone is worse than the SLP's, its not worth the 1/2".

Really loud drone. Which I love!!!
The alignment is going to be guess and check. Loosen the clamps on the other end of the axle for more adjustability.

Good luck. Don't let those things melt your bumper.

Stoenr... I have a video of my car on the dyno with the PowerFlos. It's not hosted anywhere right now, but I can e-mail it if you want to hear it.

These things are awesome. The drone that I usually get is when I first start the car up and let it run. I have the same set up as Paul with the K&N, however not sure if the H/O is in or not. This thing sounds like heck on wheels.

With my Bassani's I had to loosen the midpoint clamp and adjust. Might try that.

Thats exactly why I didnt want to start my car up when I had the mufflers off( was afraid it would sound too good!) Any way dont bend brackets bend the hangers, my JBA's driver side was hanging too low so I just bent the hangers down about an inch or so to compensate. hope this helps :nice:

I took another look at my alignment issue last night, took off the muffler, tried bending the hangers, all to no avail. By the look of it, the rear most hanger needs to be lengthen about 3/4 inch (or relocated on the muffler) for the tip to center up in the cut out.

Also, the top of the muffler is so close (less than 1/4" clearance) to that lower bolt holding the bracket on, they constant hit making a lovely clanging sound.

I'm just going to run by a custom exhaust place today or tomorrow and see if they can weld me in a fix.

Thanks for the info everybody!

Next problem to address will be the drone. Solution: CAI :banana:
The drone just gives me motivation/justification to do it sooner than later! If that doesn't work, different mufflers. We'll see...

Initially, when I installed the same kit, the drivers side would not line up at all. It was down and to the right about 2 inches each way. I checked and double checked the entire setup. Nothing I could see at the time would have explained what was happening. All I can say is that after an hour of looking at it yet again, I loosened the bolts, snugged the muffs onto the pipe and reset it yet again. It fit perfectly. So obviously it was something to do with the alignment on the pipe.

My driver's side was a pain to align as well.... was great when I first put it in, but the clamp loosened up some and the tip moved closer to the right.. Put her back up on the ramps and loosened up, re-aligned and then re-tightend so far so good... The install instructions recommend welding vice the clamp... This might be the final solution if this happens again... As far as drone goes I very rarely drive around with the engine operating for any extended periods at 2000RPM... If I recall 2 grand in 5th nets a paultry 55ish MPH and seems to be on the verge of lugging the motor... I tend to use 4th gear if I've got to hang around the 50-60 MPH region... (FWIW)....