Exhaust mod

I like to read the Liberty CRD forum at LostKJs.com. One of the popular mods for the diesel is to ditch the restrictive stock exhaust. People report improved driveablility and fuel economy.

I ordered a Magnaflow muffler (P/N 12226) from Summit Racing.

The muffler is unpolished stainless steel.

The Magnaflow is straight through with minimal restriction.

Here is a comparison with the stock muffler. The CRD exhaust is 2 1/2" from beginning to end except for the restrictive muffler where it necks down to 2". A good example of corporate cost cutting. It literally took a minute with a SawsAll to remove the stock muffler.

The 2 1/2" I.D. inlet fit perfectly over the factory pipe.

I used a hanger to mount the exhaust. There is a flex joint in the factory exhaust before the catalytic converter that makes positioning the exhaust easy.

I finished the installation with a scrap piece of flex exhaust pipe I had. I'm going to run a side exit exhaust for awhile to see if I like it. I get an oily buildup on the rear window I attribute to the diesel exhaust. If I like the side exit I'll do something nicer than what I've rigged up here. I left the rear part of the exhaust in place in case the side exit doesn't work out.

Test drive - DEFINITELY drives better! Much more responsive. I made the Traction Control kick in a couple times. It sounds as quiet as stock to me. Time will tell on any fuel mileage increases.

Another thing I've noticed...with the factory exhaust when you lifted off the accelerator the Jeep would decelerate. With the exhaust mod it now coasts. The factory muffler seemed to be acting like a mild exhaust brake.

Update April 2006

After running the side exit for a month or so I decided I liked it. I also removed the muffler to see how loud it would be and it wasn't much louder than with the muffler. I'm going to run it this way for awhile and see if I like it. I bought a chrome tip from Summit Racing (P/N SUM-690052).

Here is a shot of the exhaust setup with no muffler. Sound clip of open exhaust

I got a section of 2 1/2" mandrel-bent pipe (Summit Racing P/N MPE-10716) to build a final exhaust. Even though I liked the open exhaust, I've decided to use the muffler since it makes a great coupler between the catalytic converter and exhaust pipe.

After some test fitting I cut the pipe at 90 degrees.

The pipe fits perfectly into the muffler.

The chrome tip fits perfectly over the pipe.

The cut pipe fits nicely inside the muffler and gives me about 15 degrees of adjustability.

After some more test fitting I welded the exhaust pipe to the muffler.

Here is a shot of the system under the Jeep. Following are a couple pictures of the exhaust relative to the Jeep.

After a couple months of testing and pondering this is the final exhaust. Sound clip of the Magnaflow exhaust

Update 5/2007 - Never satisfied, I put on a 3" exhaust.

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