I just put a 50 Series Delta Series Flowmaster on my 2006 Dodge Ram 5.7 Hemi. It is a single 3" inlet/dual 3" outlet ran just after the cats and "Y", ran straight out the back w/3.5" chrome tips. Other than the exhaust, everything is stock. I noticed that at high flow, like 3rd gear floored and at 4000+ RPM, i get a "muffler screach" as I've heard it called. It's like a constricted, high-pressure, air-rushing-by sound, over the normal flowmaster sound. Almost like having a plugged up cat or something. I am hoping this can be explained by someone in this forum. I wouldn't have thought that replacing the stock exhaust's 3 mufflers/resonaters with a Flowmaster would make the exhaust sound more restricted. It feels like it has a little more power too. So I'm baffled what the noise could be, any ideas?

Thanks

 

My first ram was an 04 with cat-back dual magna flows, the first time I stabbed it I heard the straingest noise at the end of the shift point. I came to the conclusion that the noise was normal, probly just distortion from the oversized pipes that come with the new exhaust. I would'nt worry.

 

I had this same problem with my 40 Series. The culprit was the pipe size. I had 3" on at first, and when over 4000 RPM's, it sounded just as you described. I got rid of it by making the pipe smaller - dual 2 1/4".

 

Thanks for your input. I don't think I'll downsize the pipe though. Hopefully, I'll be able to compensate by putting more in on the intake side :-)

 

i have a imco muffler on my 04 it sounded awesome until i put long tubes on it. Now it's making a weird noise coming from the front and when driving on the highway you can hear it pretty bad from the passangers side. I can't describe the noise. I say it's a chopping sound from when the exhaust fumes meet in the collector then go to the cats and such on. My friend says it sounds like a bad rocker (kinda a fast paced tick/chopping sound) i'm trying to find the cable to my camcorder so i can post a clip.

 

That is what I thought too, so I bought a K&N CAI. It changes the tone, but only slightly. I'm telling you, if you want to gid rid of the tone, make the pipe smaller. It adds more low end power anyway (yes, engines do require some backpressure). I had the 3" pipe on for about a year, and felt a loss in power under 2500 rpms. Using a smaller pipe added it back, made the exhaust deep throughout the power band, and got rid of that ugly, raspy sound.

If you look at the Flowmaster site, they have recommendations for pipe size. Our small blocks do well with 2 1/2" or less. 3" pipe is for something making over 400 hp.