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I have looked many times at the possibility of adding true dual exhaust without losing ground clearance. I started looking around and found this picture. I don't think its real....Don't know how anyone would have got a shot of their XK like this...But it made me think.

I did some measurements and found the stock muffler is 30 inches long 12 inches wide and 6.5 inches tall. Looking at some of the Flowmaster 44's (which would be way loud I know) and they are only 13 inches long, 9.75 inches wide and 4 inches tall. Doesn't leave a whole lot of room but it would fit. I also have a couple of Glass Packs that i had put on my mustang in High School. They are only 4 inches round and 18 inches long. Plenty of room.

So i thought...this could really be done...but I am worried about losing low end torque. It would increase HP but I'm not real interested in going faster. Just having more power without it feeling slushy at low RPM. The pipes coming off the headers look to be about 2.25 inches in diameter. I wonder what running 2.25 inch pipes all the way back would do?

What do you guys think?
 

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This is indeed a true dual but you could also use a single muffler with dual inlets and dual outlets. It would maintain the dual exhaust performance and also act like an H-pipe to balance the back pressure. It would also eliminate the space issue for the muffler. GREAT FIND!!!!
 

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The rear drivers side has a big black box right where that pipe comes out. Not to say you couldn't move it to the inside of the rail but then the spare tire would have to go.

Good find though! I'd love to see someone do it.
 

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The rear drivers side has a big black box right where that pipe comes out. Not to say you couldn't move it to the inside of the rail but then the spare tire would have to go.

Good find though! I'd love to see someone do it.
That would be the charcoal canister. I just replaced mine the other day. Im sure that it can easily be relocated inside the spare tire area.
 

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OK so it looks as tho it may be photoshoped but it still looks do-able...some one try:stickpoke::stickpoke::banana_hitit:
If thats photoshopped then that person has some skills.
 

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Sounds and looks do-able. 2.25 pipe should be fine, seeing how other 4.6-5.0 liter motors usually run 2.25 dual exhaust. I would try to incorporate an "X" pipe into the mix if at all possible. Or as suggested (Adamag25) in another post, a dual in/out muffler, which will help with the "scavaging" of the exhaust. To make things easier, not as "cool", but have the exhaust exit the same side of the XK. I actually like the look of the stock tailpipe, where it really does not show, giving a "clean" look. I may have mine done around X-mas when $$ gets better.
 

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Actually, you could ditch the resonators.

Rob
Does that make any difference in response or sound ? ,, any negatives ?
 

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I would certainly rather have 1 - 3" pipe over a dual any day of the week.....but that is just my opinion. We will see how it comes out.

what is the point of a dual exhaust if it shares a muffler, and or has an xpipe? It would add about 50 lbs more, spread more heat under the chassis, and be more prone to damage..If Looks/sound is the objective, then the function question goes out the window.
 

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I am speaking for the majority of Commanders out there that are utilized as a utility and off road vehicle. If you are racing, and bumping the rev limiter, or want to wake the neighbors, disregard my jibberish....I Still would love a 2wd SRT8 XK!!(with duals)

an x pipe on a Jeep Commander is pretty useless in my opinion. Same as the dual exhaust. If you want efficiency and torque, there is nothing better than a single. Dual exhaust is meant for horsepower at the top of the power band, which our Jeeps never see but for a split second.

FACTS:
a 3" i.d. pipe = 113.09" of surface area/ft.
two 2.5" i.d. pipes = 188.49" of surface area/ft.
YOUR NOT DOUBLING ANYTHING WITH DUALS-EXCEPT WEIGHT AND MONEY

Save the X-Pipes and the duals for mustangs that need velocity, flow and scavenging to produce Mid toTop end HP.

More scavenging = less backpressure
Less Back pressure = less torque
more velocity = more torque
More Flow = more HP

I am torque fan. Besides, that is what pushes you down the road, HP is what accellerates you past the dumptruck in the passing lane. A mandrel bent, high flow, well designed, single will give you the best of both worlds and be much lighter than stock. Less weight = more gear!!!






(MG's Math disclosure..I don't make this stuff up...:icon_confused:)

surface area is about equal to the limits of the volumetric gas expansion-

Inside surface area of an 12" long 3" id exhaust pipe:
=pi*Diameter*Length
 

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Don't think anyone mentioned that they were "racing" their Commanders. The initial post is if duals can be done on our vehicles. There some individuals who just like the look of 2 exhaust tips on each side of the vehicle. Since it appears noone has done this, seemed like a fair quesitipn. If someone were to go this route, it was mentioned the idea of an "X" pipe incorporated in the design. As far as "waking the neighbors". The article in the link states that the "X" pipe quiets the exhaust note. I do agree that a single 3" is a great way to go, as I am having a single 3" installed on my SVO, and I am removing the 2.5 duals, as it will help flow since it is a turbo car.
This post did not seem as a "highest horsepower" question, just a "can it be done?".

Great information for either direction someone wants to go.
 

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I..If Looks/sound is the objective, then the function question goes out the window.
I didn't mean to argue about someones favorite color....just inform people that think duals are the answer to fuel economy and overall performance.

Yes, I agree with you...it can be done...funny: my brother has a Burns Stainless 4" turbo back exhaust with v-band clamps, hollow ss hangers, and a flush turn down tip....:rofl: on his civic!

I also agree with you guys, that if the object is to have twin tips, single in, dual out would be the least expensive and most beneficial.
 

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Don't think anyone mentioned that they were "racing" their Commanders. The initial post is if duals can be done on our vehicles. There some individuals who just like the look of 2 exhaust tips on each side of the vehicle. Since it appears noone has done this, seemed like a fair quesitipn. If someone were to go this route, it was mentioned the idea of an "X" pipe incorporated in the design. ....... Great information for either direction someone wants to go.
While not true duals I do have 2 exhaust tips. See post #35 in My Garage thread.



 

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Discussion Starter #17
I have done some more research and am convinced this would kill Low End Torque. I was really considering it....but I think i will let someone else be the guinea pig.:)
 

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You can always do a dual 2.25" in to a single 3" out and also get the dual pipe look. I am going to one day change mine to that. I currently have a 3" in/out with a dual tip.
 

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hey guys new here, but I am huge into exhaust systems and have had many. If you truly want true dual exhaust, I would highly recommend using an x-pipe. The increase in the scavange effect greatly increases horsepower, torque, and quite importantly gas mileage. 2.25 or 2.5 inch pipes will fit, but make sure you spend the money and have a quality shop do all of the work. If you're on a bit of a budget but want some sound and performance just stick a quality muffler (flowmasters are awesome, always have had them and always will) and possibly larger pipes. Don't waste your time worrying about the resonators. They're a waste of money and space. Keep in mind a lot of the muffling comes from your cats too. Think about replacing those also. I put them on my car when I had it and they were incredible. Such an improvement in flow and gas mileage I was amazed. And no they do not mess with your emissions. The most important thing to keep in mind though is the fact that an exhaust is not a simple cheap change. So make sure that you do what you want and not what you think everyone else does. good luck and send us info on what you decide
 

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Does that make any difference in response or sound ? ,, any negatives ?
I apologize Ahmed.
I did not see your question till tonight.
A resonator softens the exaust pulse (drone) that exists at certain RPM, usually at cruise speeds.
Some engine/muffler combinations can really drone or resonate and the resonator breaks up the remaining sound waves.
I don't know about your export 07 4.7 but my 07 4.7 does not have a resonator.
The 08/09 4.7 305 horse versions did have a resonator.
It appears all the Hemi's have resonators.
I don't know about the V-6 systems.
Maybe the higher output 4.7 developed a drone, so the resonator was added.
I can only guess.
The resonator can be looked straight through....it has a pipe with many holes running through it.
I believe the exaust pulses are stabilized as they go through it.
It generally costs no horsepower or torque.
If a true dual exaust was substituted the resonator MAY not be needed, depending on the mufflers design.
My Impala's (1995-1996) required them with the Borla muffler design...they droned like crazy around 65 mph.

What I would say though, and only those with the Hemi's and low restriction exaust can answer.....how do those things sound while in MDS mode?
I can't help but think they would have a real low amplitude drone.
Yes/No?

Rob
 
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