Exhaust Preferences

[TJ805]

Just did a 4.6 in my '01 XJ, and would love to hear some exhaust options or suggestions. Not looking to eliminate the cats, so I guess a muffler is my only option? I don't want to sound like a high school kid either, just a nice low pitched rumble would be nice...

[Cheromaniac]

You need a 2.5" system from the header downpipe to tailpipe with a high flow cat and muffler. Since you want a low pitched rumble, go with a chambered muffler such as the Flowmaster.

[PJV52284]

My current exhaust setup on my 03 WJ 4.0 has the stock manifold and 2 precats, 3rd cat removed, 2.5" pipe with a Flowmaster 70 series. Due to the 3rd cat removal, it has that extra little "hollow echo", however It has a nice low rumble on cold starts, the volume tones down a little once warm. Its not obnoxiously loud, weather it be a cold start, or idling when warm. Getting on the skinny pedal really makes it sound nice in higher RPM's.

I bought my complete exhaust system just over a year ago. I got the Doug Throley headers, Magnaflow pre-cats/down pipe, Magnaflow High-Flow cat, 2.5" pipe, FM 70 muffler and a 2.5" mandrel bent tail pipe all from Kolak.

I got excited when it first arrived, and cut out the stock cat back, and installed the back half of the new exhaust, almost right away.

Now that I have more free time available, within the next week or so, i plan on installing the header, pre cats/down pipe, Magnaflow cat, along with 4 new o2 sensors, motor and trans mont, and a few other things im sure im forgetting.

[camojeep88]

You need a 2.5" system from the header downpipe to tailpipe with a high flow cat and muffler. Since you want a low pitched rumble, go with a chambered muffler such as the Flowmaster.

not to hijack just curious as to why a 2.5 from the downpipe? how does that work with the driveshaft? and with a long arm kit i dont see 2.5 working from the down pipe without crushing it to clear...im not saying go to the ghetto muffler shop and have them bend sonething out of fence pipe but mandrel bent 2.25to max the cat and 2.5 from there back just to clear everything and keep everything tight. this is my current set up and it dumps after the axle with a magnaflow muffler. doesnt drone in the cab and still has a nice throaty sound to it

[Cheromaniac]

A 2.5" downpipe provides the necessary exhaust gas flow for a mild stroker but, depending on your suspension set up, you could run into clearance issues from the front driveshaft. My Jeep was stock height so clearance wasn't a problem.

[agalloch07]

I have a Borla cat back but the tail pipe on it is only 2" is this too small for a stroker?

[SkylinesSuck]

Yup

[Cheromaniac]

I have a Borla cat back but the tail pipe on it is only 2" is this too small for a stroker?

Possibly. Keep in mind that as combustion gases pass down the exhaust system, they cool down and occupy a smaller volume. Therefore it's more important to have the larger diameter piping upstream i.e. closer to the engine. As the gases near the tailpipe, you can get away with slightly smaller piping.
The Borla catback should have 2.25" piping which might be a little small but shouldn't be too restrictive for a mild stroker that'll rarely go above 4500rpm.