I have a 2002 FX4 with the Triton 5.4 and a K&N intake. I had my exhaust shop put on a Flowmaster 40 series 2.5" single inlet and daul 3" outlet i believe. Unfortunatly I did not research and i am not happy with the sound or the performance. I do not have a H or X pipe in it and it feels like i have lost horsepower and it is just not loud. I have since then read that the 40 series is supposed to be the loudest that flowmaster makes. What is the problem? How can i get some noise? Thanks in advance for any suggestions.

 

Mine got louder after about a week of driving. I was at disappointed at first, now I am happy, would not want mine any louder.

 

dual 3" outlets in a 2.5" inlet??? i didnt know they made a muffler like that but if they do thats why its quiet... sound waves cancel eachother out...

 

You have a SI 3in DO 2.5 inches. If you need it louder, IMCO Extreme 1 chamber is the way to go. Mine blows the 40 Series I had dumped under my truck out of the water.

 

Are the dimensions the same on the IMCO as the flowmaster or would i have to change all of the exhaust tubing that is behind the muffler and do they also have the single SI/DO? I have been to the website before and listened to some of the clips and i love the way they sound. I am just curious if those are enhanced recordings with some other type of motor and what not.

 

if a Flow 40 isn't liud enough but you liek the tone, just get rid of your muffler. Don't waste your money on any other one. If you like you split rear exit, get a y-pipe.

 

Are you saying just drop the muffler and run strait pipes out of the cats to the back with the y pipe? Would that cause me to lose any torque or be harmful on my motor because of the loss of backpressure on the engine?

 

You must have got the "Delta Flow" 40 Series. Flowmaster has 2 types of mufflers in the 40 series. Delta Flow (more mellow sound) and the "Original" 40 Series (louder but with more drone). As far as losing torque and what not by running straight pipes, I've read differing opinions on here. The best way to find out is to just try it and see what you think. Or, maybe yours will get louder like someone elses did that posted yesterday.

 

Chosing Flowmaster and 3" pipes causes the loss of exhaust veliocity and therefore performance. Dual 2.5" pipes are good for the 5.4L.

 

My Flowmaster is SODO. The pipes out are 2 1/2 inch with 3 inch tips that are 18 inches long. I have a slight highway drone. Not enough to annoy, but enough to know you have dual exhaust. It is very throaty on crank up and makes a nice sound as you accelerate. I like it.