Jeep Commander Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
I may be crazy, but I recently experimented with several exhaust systems and have discovered the following:

Leaving on the resonator and replacing the factory muffler with a glass pack, produced a vaccum cleaner-like sound. no real hp gain. also too loud

Leaving on resonator and replacing glass pack with flowmaster. Could barely hear it. Sounded like a gerbal in a soup can.

Removed resonator, left on flow master. louder, but sounded like a racoon in a 5 gallon bucket.

Removed flowmaster and installed magnaflow muffler. beautiful deep sound, but a little too loud. Welded glasspack behind magnaflow. Awesome sound.

HERE IS THE PROBLEM!

With all aftermarket mufflers, when the mds kicked in, a horrible audible "drone" could be heard. It became very annoying--To the point that I have put the stock muffler and resonator back on! Very quiet. O well!

Hell, it's still a hemi......it's plenty fast enough!
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #2 · (Edited)
Clarification on the "Drone".

If the 5.7 engine really does shut down to 6 or 4cylinders, naturally, it will produce a different exhaust note. Or at least that's the case with my 2wd 5.7. With the stock exhaust, you will not notice this sound. The factory muffler does a fantastic job of hiding this noise when the mds kicks in at cruising speed. But at cruising speed, any constant cruising speed, you will hear this noise with some aftermarket mufflers. As best as I can describe, It's simply a dull sound, like a bumble bee on pcp!

Does anyone else with an aftermarket muffler have this problem?
 

·
Registered
Joined
·
122 Posts
Did you do all the welding yourself?
I always wanted to know what the results were when doing your experimental changes. Great info!

I noticed our 5.7L has two small catalytic converters before the join to one pipe before the flange to the large resonator. I guess the extra spark plug per cyclinder helps with the emissions quite a bit. I just cringe on the fact that I have to change 16 spark plugs when the need arises. :(
 

·
Registered
Joined
·
107 Posts
Different mufflers produce different sound on different vehicles, if your welding and testing setups I'm sure you know that, you mentioned Flowmaster, my exepriance with them has been interesting, I used a set of there 3 chamber muffers on a 67 Mustang street car I had, they sounded fantastic, I ran a set of there 2 chamber mufflers on a 5.0 Mustang race car and they also sounded great, bought a cat back for for my V-8 Ford explorer and it sounded terrible, so bad I kept for about 2 weeks and had it pulled in favor a muffler shop fab job with a dynomax muffler, which sounded great, on my current summer toy no one runs them, people have tried but they sound terrible at anything past 2000rpm, you might try Dynomax or a Magnaflow muffler and pull the resonators. Nice job on the testing, these are the posts I love to read, your being a trendsetter for all of us.:D Todd
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #5 ·
I did try a magnaflow without the resonator. I put a straight pipe behind it. It sounded really nice, and felt like it pulled stronger. The problem was the interior noise level. under full accel. it was unbearable inside the cab. When I added the glasspack behind the magnaflow, the interior sound level was tolerable......But when the mds feature engaged(at cruising speed) the drone returned as well!

My current setup is the stock muffler with a glasspack behind it, replacing the factory
resonator. I also removed the splash plate blocking the air inlet. With it removed, you in effect have ram air!
 

·
Registered
Joined
·
122 Posts
When you say resonator... it's the middle device right? Not the one closest to the rear.

I'm still deciding whether to go the full Magnaflow catback system route ... or custom-piece together a Magnaflow/Dynomax muffler and rear resonator/glass pack combo. Cost vs. performance gain is key here.
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top