I had a flowmaster 40 installed along with 3" pipe from the y back about 2 months ago. At around 2000 rpm I get a very loud droaning noise inside the cab. It sounds great otherwise. Cruising down the highway in OD my rpm is around 2000 and I can hardly stand it. With OD off you can hardly here it. I am thinking of replacing the muffler with a 50 series. Does anyone have any experience with this.

1998 F150 SC 5.4

Rick P

 

My friend jess might no, hell be on later

 

I don't know about the 50 series but I had the 70 series delta put on when the truck was new. Initially it was a tad louder than stock. However, now the truck exhaust is quieter than other F150's I've heard. There is more resonance in the cab than sound outside the vehicle- like when your driving next to a wall you can't even hear the exhaust.

I attribute some of the interior sound to the camper shell I have on the back. Shells have a tendency to increase exhaust noise in the cab.

It is so quiet I checked into getting a 50 series but haven't pulled the trigger on that purchase. The exhaust shop claimed there would be no performance difference between the different series flowmasters. I called flowmaster and the tech there confirmed this statement.

Tim

 

Pilot10

Did you keep the original pipes or did you get a larger diameter.

Rick P.

 

Kept everything else in place, just cut the original muffler off and had the new one welded on. I'm sure I could get it louder with a wider tip. However, I'm torn as I don' want to listen to exhaust resonance for hours on end while traveling up skiing. The plan was to do the whole exhaust later when I added headers. Haven't got around to that yet and I'm hoping to trade the truck in shortly.

 

Thanks for the information. I will let you know what difference the 50 series made when it comes in. Maybe going to 3" pipe is causing all the resonance. Going through the rockies this summer pulling my trailer you could sure here the noise outside, especially going through tunnels.

Rick

 

I had the Flowmaster 40 replaced with a Flowmaster 50 SUV Performance muffer today. What a difference. The cab is much quieter. No more resonance at 2000 rpm. When you step on it, it still sounds nice. At idle it is pretty quiet, not like the 40 series. I am heading out to the cottage tomorrow with my son for a weekend of golf, so that will be a good test for noise on the highway.

Rick

 

RTPALIN: Where is the muffler located under your truck? If the muffler is right under the cab...then that is the reason for the excessive resonance. Instead of buying a new muffler and having it installed again...see if you can have it moved under the rear of the bed. The farther from the cab...the less resonance

 

I had a 50 series and it was fairly quite until you really lay into it, not too long ago I removed the muffler and to my surprise it is sounds very nice with no drone, not to mention it costs a fraction the price at the muffler shop.

 

The muffler is only a few feet in front of the rear axle. I just put 400km on the highway and it sounds just right for me now. You can just hear it cruising down the highway and went you step on it, it sound real nice.

Rick