[soldierguy]

I took off the Gibson cat-back yesterday and went back to the stock exhaust. I hated to do it because the Gibson sounded nice most of the time and the stock exhaust is SOOOO quiet, but I had to. The drone at highway speeds was really bad, and it just sounded bad when MDS kicked in...I found myself just tapping it into 4 instead of leaving it in Drive just to avoid the MDS sound. The Gibson was great when I wanted to hear the engine, but too loud the rest of the time. And it oddly seemed louder at low RPMs and light throttle than it did at heavy throttle and high RPMs.

I really liked the Gibson single exhaust I had on my old Dakota, but I think it worked better there because the bulk of the replaced exhaust system on the Dakota sat behind the cab, so the sound really didn't get into the cabin all that much. It just seemed like in the Jeep that the sound would resonate up through the floor and turn the entire cabin into a giant bass box...not what I was looking for.

Oh well...back to listening to my MP3 player rather than the engine

And in case you're wondering, the Gibson is not available to anyone who wants it...the shipping costs from Korea would be astronomical, so I just put it in the recycle bin.

[paultyler]

Good move. I don't blame you.

I had to do the same thing to a brand new magnaflow on my YJ. Wayyyyyyyy to loud. There is something to be said about enjoying the quiet ride of a stock exhaust. This whole "tone" thing is way over rated.

[BlaineWasHere]

SISSY! but it back on... I can barley hear my music over my MT's, wind noise, and FM40...

[soldierguy]

Originally Posted by BlaineWasHere

SISSY! but it back on... I can barley hear my music over my MT's, wind noise, and FM40...

LMAO! That's the way it was in my old Dakota, but it worked...the whole truck had the attitude for the MTs, exhaust, lift, etc. The WK just seems more at home being quiet...something about the leather, stereo, moonroof, etc...just seems to be fine stock.

Maybe when I get back to the states I should pick up a ricer or VW to mod out so I can still have fun modding a vehicle...to me modding a vehicle is all about finding the personality of the vehicle and expanding on it. Either that or an old Wrangler to have fun with...so many ideas running through my head!

[01amberfirewv]

Find some SRT mufflers I would think they would be slightly louder but not too loud. You could probubly swap mufflers and stick with the existing exit point

[Kolak]

The Magnaflow catback for the WK HEMI appears to be the quietest right now, with the least drone. I hear they're redesigning it, however, to add a resonator near the tip section. That should eliminate all traces of drone.

I'm looking for someone in the Phoenix area to serve as a prototype vehicle for a 3" HEMI exhaust. Lots of perks for whoever is willing -- PM me if you are interested.

[jeep_on]

Originally Posted by Kolak

The Magnaflow catback for the WK HEMI appears to be the quietest right now, with the least drone. I hear they're redesigning it, however, to add a resonator near the tip section. That should eliminate all traces of drone.

I'm looking for someone in the Phoenix area to serve as a prototype vehicle for a 3" HEMI exhaust. Lots of perks for whoever is willing -- PM me if you are interested.

Well crap, that all most makes me want to run out and buy one. ALMOST. Maybe ‘buy’ on and bring it back in 30days as ‘I’m not satisfied’ LOL.

Good luck Nick. I spend all weekend in the valley (last week) and saw plenty of Hemi Grands. I’d go hit a driver up in a parking lot.

[SYCOHEMI]

Weird. I love my Gibson. I thought it was just about perfect. Under throttle, the K&N FIPK is probably louder than the Gibson. But neither in a bad way.

[3labs]

Originally Posted by soldierguy

I took off the Gibson cat-back yesterday and went back to the stock exhaust. I hated to do it because the Gibson sounded nice most of the time and the stock exhaust is SOOOO quiet, but I had to. The drone at highway speeds was really bad, and it just sounded bad when MDS kicked in...I found myself just tapping it into 4 instead of leaving it in Drive just to avoid the MDS sound. The Gibson was great when I wanted to hear the engine, but too loud the rest of the time. And it oddly seemed louder at low RPMs and light throttle than it did at heavy throttle and high RPMs.

I really liked the Gibson single exhaust I had on my old Dakota, but I think it worked better there because the bulk of the replaced exhaust system on the Dakota sat behind the cab, so the sound really didn't get into the cabin all that much. It just seemed like in the Jeep that the sound would resonate up through the floor and turn the entire cabin into a giant bass box...not what I was looking for.

Oh well...back to listening to my MP3 player rather than the engine

And in case you're wondering, the Gibson is not available to anyone who wants it...the shipping costs from Korea would be astronomical, so I just put it in the recycle bin.

Just a thought, why don't you put some insulation in the "tail gate door". I did it on
my '05 WK, just a few screws & snaps (do not block the latch release). I used 2"
thick foam & used the spray foam insulation around the window (poped off the oval
rubber stoppers & shot foam in there, let dry & reseal). Worked like a "bandit", cuts
the noise wayyy down ! I removed the "resonator / tail pipe" & attached a crome tip !
This trick helped cut the (lack of resonator) noise to nothing ! Let me know if this works for you, quick, get over to the recycle bin & retrieve !

[3labs]

[QUOTE=SYCOHEMI]Weird. I love my Gibson. I thought it was just about perfect. Under throttle, the K&N FIPK is probably louder than the Gibson. But neither in a bad way.[/QUOTE)

Have you been able to find a "throttle body spacer" for the 5.7 !?!
I was watching the Speed Channel the other day & they were installing one
on a 5.7 Hemi Charger...
(they said it works on a 300 / 5.7) ! Anyone think the Charger unit would work
on the WK Hemi Jeep !

Let me know...Black Lab

[Intrepidjeep]

What good does a throttle body spacer do nowadays? They seemed like a gimmick to me on multi-port-injected vehicles.

The stock exhaust on my Durango is even quieter than the Jeep's stock exhaust -- essentially inaudible inside OR outside the vehicle. At least in the Jeep you can hear a nice V8 burble and a little bit of mild exhaust rumble outside.

[Kolak]

Just came to my attention that the Gibson catback for the WK and XK is 3" diameter. Can someone verify this?

Also, is there both a muffler and a resonator as part of the system?

[SYCOHEMI]

Originally Posted by Kolak

Just came to my attention that the Gibson catback for the WK and XK is 3" diameter. Can someone verify this?

Also, is there both a muffler and a resonator as part of the system?

Yes there is definitely a muffler and a resonator on the Gibson. You can see the resonator in the picture.

My vehicle was used as the development vehicle for the system. They spent extra time developing a system that would not drone in the vehicle and that was reasonably quiet.

The exhaust on my M5 is a Tubi Style exhaust that currently retails for $3,000. My M5 was sound tested and professionally recorded by EA Sports for the Need for Speed soundtrack. So, I am reasonably particular about exhaust tone.

I am surprised that you find the sound objectionable. It's definitely not quiet, but I think it sounds nice.



It's too hot to measure diameter right now. I'll try to do it if I remember.

[Intrepidjeep]

It occurred to me today, thinking about the droning problem, to ask about the exhaust system mounts that were used. Were rubber hangars used all the way back?

Some shops will just weld a steel rod to the frame above, and the lower end welded to the pipe/muffler. That supports the weight and keeps the exhaust system well located, but it also transmits exhaust drone directly to the vehicle's frame. They should have used some sort of rubber hangar. If there's direct steel-to-steel contact between exhaust and vehicle anywhere along the exhaust system, then it's bound to be noisy.

[Kolak]

Thanks for the photos and information about the Gibson. Nice to see they are using a resonator to assist in eliminating droning when the MDS kicks in. Seems like most people are pleased with the Gibson, but I still think more can be done to maximize the flow of the exhaust without adding much cost at all. I sure wish someone local to me here in Phoenix would step up so I can do some tinkering. Volunteers? If I don't find someone soon, I'm going to rent a WK for a month for a few projects.