We currently have a flowmaster 40 on our 99 Expedition 4.6L, the highway drone is really getting annoying. Would a 24" glasspack(in place of the flowmaster) cut down on the drone or what are our other options. It is a single stock exhaust w/ flowmaster in place of the stock muffler...

 

Cut That Crowmaster Off And Install The G-pack! The Flow's Always Sound Good At First, Then Rapidly Become Annoying. I've Had Them On Every Vehicle I've Owned, But Never Again. They Are Overpriced Garbage. Every One I've Had Has Cracked At The Chamber Spot Welds Within Two Years, And At $80, No Thanks.

 

I'll say more calmly that that is simply a characteristic of the FM40 series. You could try another style of muffler. The glasspack will burn out on you in a couple years and you'll have to replace it. A MAC Flowpath would probably sound good, or else some sort of turbo or superturbo muffler maybe? Not too much backpressure in those ,and they give you great sound in the upper rpm's. The Flowpath's sound wicked...

 

I agree with Saurian...
You can also try out Magnaflow mufflers or larger cased Flows if you don't want to lose the tone. The 50 series deltaflow should work just fine.

 

are you guys just talking about replacing just the muffler as stated, or something else? I am looking to just replace the muffler as well because of $ at the time, I can get the flowmaster cheaper than the magnaflow, just wanting to do muffler for now then get 3" SI SO later, also , any difference in MPG or low end performance or lack of?

 

You could try a quieter model Flowmaster like the 50 series delta flows or the 70 series. I wouldn't go with a glass pack, they don't last very long.

 

Stopped by the local muffler shop last night, flowmaster 70 installed for $150. Thats what should have been installed the first time....

 

Rukmns, keep me posted on your results, as far as low end, hwy drone, & mpg's, just replaced muffler only right?

 

Will do, so far alot quieter but its twice the size of the 40....

 

more chabers in it, that's why it's longer, keep me posted, thanx