Originally Posted by fourpointsix

First, I will talk about these trucks and what I have learned today. I went to a different muffler shop from my normal one and the owner explained to me the 5.4L is a much quieter engine than the 4.6L in all applications. This will explain the discrepancy between the loudness of my vehicle compared to mattadams' truck with the 5.4L.

Secondly, regarding Magnaflows in general. Higdogg, I agree with you 100% that the Magnaflow is the best sounding muffler for these trucks. It is the deepest sounding muffler I have heard, and it is extremely smooth throughout the RPM range.

I had the opportunity to hear the IMCO and Magnaflow side-by-side last night. My cousin just purchased a 2006 F150 4x4 with the 4.6L engine. He put the short 14" Magnaflow on his truck in the stock pipe with a 3.5x18 inch angle cut tip. We had two friends drive our trucks and do runs down the street one after the other. They would drive easy, moderate and WOT back and forth so we could compare the sounds of the two mufflers. While the IMCO is definitely louder, the 14" Magnaflow is ALMOST as loud, and is deeper and smoother by quite a bit. I must say it embarassed the IMCO. On a 4.6L, the 14" Magnaflow is louder than a 40 Series Flowmaster.

Today I had the 18" Magnaflow installed on my truck. I had it dumped before the rear axle. It sounds just as deep as the 14", but the volume is lower. With the 14" there is a reasonable drone on the highway w/ 3.55 gears at 65-70. With my 18" there is literally 0 drone. As far as power goes, my truck is the most responsive it has ever been, with the Flowmaster being the weakest and the IMCO being alright. I will now rate all the mufflers 1-10 with 10 being the best so that everyone on here can learn from my 3 exhaust experience and only buy 1!

Flowmaster 40 Series (dumped)

Volume: 7
Sound Quality: 7
Performance: Lost low end

IMCO Extreme 1-chamber (3 inch tailpipe)

Volume: 10
Sound Quality: 8
Performance: Better than the Flowmaster, still some low end loss from stock

Magnaflow 14" (2.5 inch tailpipe)

Volume: 8.5
Sound Quality: 10
Performance: Better than stock

Magnaflow 18" (3 inch dump)

Volume: 6
Sound Quality: 10
Performance: Better than stock

Moral of the story is: When people on here recomend Magnaflow they aren't kidding! I'm sold on these mufflers. It's a straight pipe with insulation. It doesn't get better than that!

Originally Posted by SoundPer4mance

flowmasters are loud, but i got a loss of performance with mine, lost all the low end torque, and at high rpm it just really raspy instead of louder. let me post up a vid of my truck on the dyno, wtih a SISO magnaflow cat back

im a mangnaflow man through and through, excellent, refined sport exhaust sound, not loud and obnoxious, no gargling off high rpm (just listen on the dyno) ill use magnaflow for everything now, definately

vid is mangnaflow SISO with stock intake
http://www.bobsride.com/bobstruck.wmv (5.4 mb)

Originally Posted by Josiah

I just got home, and let me tell you, flowmasters get me races daily. People just notice the truck whether or not I'm idling. They then tailgate me until it's 2 lanes and we race. I raced a cobra mustang today down a main street. I started to tailgate her and noticed it was a girl in the car. It was an automatic from what I could tell. I am pretty sure it was not a kit, and the engine made a low popping that got rapidly quicker as she went faster, so I'm assuming that has to do with the supercharger they have in them. Aren't all cobra's supercharged, I hope not because I easily kept up with her until about 40mph then she slowly started to pull. I raced another mustang (I made a post about it), that made that SAME noise, but I lost early on so we let off and he took a turn. I wonder if there are "stage" packages like Roush, with SVT. I had my gf on the phone and it was right next to her work so I told her to look out (we were at the stoplight). She saw the entire thing. I then took a left into Mickey D's but on the way back there was a lowered chevy with exhaust, maybe an 03 because of the dull paint. I kept up with him pretty easily but it was a hard to judge the race because he would get on it and then let off. Anyways, my truck is not too quick with these flowmasters so I'm assuming that cobra did not have a supercharger for one reason or another, maybe that sound was a funky exhaust (someone on here would know), that 2 mustangs I've raced have had. The other mustang might have been a cobra too but it was way too dark to tell at the time and the race was too quick. Anyways, hope you enjoyed the daily adventures of my F-150. This is the only thing I like more about the flowmasters, I wish my magnaflows received this much attention.

Originally Posted by StuckInMuck

i know you have spent some money on your truck. But your not keeping up with someone who knows how to drive a cobra. a stock one at that lol. 0-whatever. it will be no contest you should have gotten owned if the chick knew how to drive