My current exhaust is long tube headers into 2.5" mid pipes into a Y pipe (dual 2.5"in 3" out) just ahead of the muffler and 3" single exhaust the rest of the way and has terrible drone. The muffler is just a generic straight through, I don't know what brand. I want to replace the muffler with a Magnaflow but want to make sure I lose the drone. Would replacing just the muffler and keeping the 3" single exhaust do the trick, or would I be better off with a different pipe size and configuration? Maybe lose the Y pipe and extend the 2.5" mids to a muffler with dual 2.5" inlets and and outlets? If it matters I'll be dropping in a 347 stroker next week so it will be moving a little more air. Open to all suggestions.

 

The muffler and tailpipe size are most of the problem, but how far back is the muffler placed? The largest Magnaflow you can get would make a big difference and if you could place it closer to the middle of the system instead of at the rear axle that will help too.

 

The back end of the muffler is about 16" ahead of the rear axle. I'm definitely looking at the larger Magnaflow, just trying to figure out which configuration. I'm not opposed to replacing/reconfiguring everything behind the headers if necessary.

 

I don't really mind a slightly annoying exhaust on a classic hot rod or something like that, but completely agree that it is annoying on a truck that you daily drive.

I found that having the muffler mounted in the original location is best for minimizing drone. My friend has a muffler mounted farther forward and you can feel the exhaust in the floor, which I am not a fan of. I would probably also suggest the largest Magnaflow. I had that on my old truck that had no cat and it almost sounded stock and was actually too quiet for my liking. A stock 2001 Dodge was more audible.

I have a Cherry Bomb Vortex and a single cat with basically no drone and a minimal interior sound. I have 3 inch single to 2.25 tails that are at 45s with 3.5x18 tips. It has a nice mellow V8 sound outside but is not loud. This sounds nothing like an annoying Flowmaster. It actually sounds more like a dealer installed cat back on a newer truck or something along those lines.

What other mods does your engine have? Does it have a cam or heads etc. That will change the exhaust sound as well.

 

The presence or absence of a cat in the system affects where the muffler works best, the exhaust on modern trucks is quiet partly because it has multiple cats breaking up the tubing lengths.

 

Currently stock cam and heads. 347 will be dropped in next week and will have Comp 35=510-8 cam and GT40 heads. As it sits the 3" pipe from the Y to the muffler is only 12" long. I'm thinking I'll leave that in place and replace the muffler with a Magnaflow 12588 single 3" in/ dual 2.5" out and exit behind the rear wheels using 2.25" pipe. Though, I've read quite a few reviewers reporting "slight drone". Also thinking about going true duals with 2.5" in and 2.25" out, wondering it this would be a more drone proof option. Not sure on which mufflers to use with this option though.

 

That sounds like a good plan to me, true duals are a pain on these truck with the location of the midship tank.

 

Which one, true duals all the way or duals from the 1 in 2 out Magnaflow?

 

Duals from the muffler back.

 

I found these, but they only come in 2.5". What do you think? Flowmaster 15828 Flowmaster Pre-Bent Tailpipes (holley.com)

 

On your straight through muffler, measure how long the body/case is, the magnaflow 12588 body/case is 22", if your old muffler, is longer, your drone will be, louder, with the new(shorter) magnaflow, if you want the drone to leave, new muffler would need to be longer than your old one, and not just 2-4", to get it to have less drone, but some like loud, some want whisper quiet, everyone's noise/drone tolerance is subjective, and totally different. My borla proxs(SISO) has a little drone with 1 cat still working, my buddy has same muffler, no cats, and carp! is it loud, and drone, at cruise speed, even with the windows up.

 

It's 18"x 9". I'm looking for quiet but not silent at idle and cruise but want what I would call reasonably loud under load. I can tolerate loudness much more than I can drone.

 

You may be somewhat right about tubing lengths being broken up by additional exhaust components, but I still disagree about having the muffler anywhere other than the stock location. Having the muffler farther forward is always worse for interior noise or drone. I have never seen where it wasn't the case.

 

I dont want to come across like Im preaching, but Ive made mistakes with exhaust systems on cars, trucks & motorcycles & this is 1 thing Ive learned & feel this is a good time & place to share it with anyone that wants to understand a little more of what is going on.

The resonator is what controls the drone by changing the note of the exhaust to a deeper, more acceptable & appreciated tone. That "cat" in front of the stock muffler is actually Ford's OEM resonator. But many vehicle owners (especially Foxbody Mustang, G35 & Civic owners) will tell you that when resonators are removed, the car drones, rasps, the floorboard shakes & everything in & around the car sounds horrible.

Mufflers on the other hand, just muffle sound. But if the sound is horrible (from lack of a resonator), then all you get is a muffled horrible sound.

Ive seen many guys of various cars chop their stock exhaust off & run aftermarket mufflers & then complain of drone, rasp, etc. Most of them end up installing "bullet type" resonators from Vibrant, Magnaflow, Jones, Borla, etc & are amazed at how greatly the exhaust changes to a deep, soothing tone without drone & rasp...by the way, the general rule of thumb is that you would want the longest resonator you can fit. And also, "bullet type" resonators do not rob power.

Some guys also use the old Cherry Bomb glasspacks before the muffler & have had good results, however, the glass eventually blows out since they are cheaply made. I would rather just go to a junkyard & pull a quality OEM resonator off something like a Northstar Cadillac (or some other high performance engine) & figure out how to fit it. Or, I would just buy the longest $80 Vibrant resonator, since there are a lot of guys that have had good results with them cutting out drone & adding a good tone.

If anyone wants to hear videos of the difference that I'm talking about, listen to youtube videos of "before & after resonators". You will hear how the tone changes drastically on some engines. Its interesting stuff that I didnt find out until I made enough mistake$ with my exhaust systems over the years: the a good resonator can transform the exhaust sound & livability of many vehicles with aftermarket systems.

 

The two 2.5" pipes between the headers and Y pipe are pretty long and would provide plenty of space for resonators. I think I'll stat with installing them with clamps and see what happens. If I like it I may just leave everything else alone and have them welded. If not then I'll replace the muffler also. I really appreciate all the helpful input.