Maryland Cherokee Club
CF Veteran
Joined: Mar 2009
Posts: 7,996
Likes: 0
From: Berea, OH
Year: 1998
Model: Cherokee
Engine: 4.0
Offering to you guys first:
2000 Horseshoe Intake manifold, Will swap with any HO motor. For 91-95, you need the steering pump bracket, which I will include for anyone that needs it.
$100 or will Trade for parts I need. (3.5" Leaf Springs, shocks, yada, yada)
Thank guys!
2000 Horseshoe Intake manifold, Will swap with any HO motor. For 91-95, you need the steering pump bracket, which I will include for anyone that needs it.
$100 or will Trade for parts I need. (3.5" Leaf Springs, shocks, yada, yada)
Thank guys!
CF Veteran
Joined: May 2011
Posts: 3,380
Likes: 0
From: Partlow, va
Year: 1994
Model: Cherokee
Engine: 4.0 i6, 307 injectors
Hey guys! Check out: http://www.facebook.com/offroadmag
Off-Road Mag posted a nice little blip on their home page..lets show them how awesome the XJ community is by "like"ing the post!
The Editor-in-Chief came out a few weeks ago and shoot a feature for Off-Road Magazine too! Should be out in a few months, I'll keep you posted when it comes out.
Off-Road Mag posted a nice little blip on their home page..lets show them how awesome the XJ community is by "like"ing the post!
The Editor-in-Chief came out a few weeks ago and shoot a feature for Off-Road Magazine too! Should be out in a few months, I'll keep you posted when it comes out.
CF Veteran
Joined: Mar 2009
Posts: 7,996
Likes: 0
From: Berea, OH
Year: 1998
Model: Cherokee
Engine: 4.0
☠ CF Sheriff ☠
Joined: Nov 2009
Posts: 15,197
Likes: 18
From: Aberdeen, MD
Year: 1995
Model: Cherokee
Engine: 4.0L HO I-6, 703 Injectors, Brown Dog Super Engine Mounts
CF Veteran
Joined: Feb 2012
Posts: 2,716
Likes: 2
From: Bowie, MD
Year: 1999
Model: Cherokee
Engine: 4.0L
CF Veteran
Joined: Jan 2012
Posts: 8,272
Likes: 1
From: Baltimore, MD
Year: 1999
Model: Cherokee
Engine: 4.0 I6 HO
Check for any of the female leads on the XJ end of the connector have gotten pushed through, and out of, the OBDII port. had the same trouble w my *cough cough* Saab. it was just one wire, but was pushed so there was no connection. just reseated it and opened the gap up a bit. never found why it did that.
CF Veteran
Joined: Mar 2009
Posts: 7,996
Likes: 0
From: Berea, OH
Year: 1998
Model: Cherokee
Engine: 4.0
☠ CF Sheriff ☠
Joined: Nov 2009
Posts: 15,197
Likes: 18
From: Aberdeen, MD
Year: 1995
Model: Cherokee
Engine: 4.0L HO I-6, 703 Injectors, Brown Dog Super Engine Mounts
mine starts out as 2.25" also, then necks up to 2.5" after the muffler when the gasses are cooler. **** works mint
CF Veteran
Joined: Mar 2009
Posts: 7,996
Likes: 0
From: Berea, OH
Year: 1998
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Mar 2009
Posts: 7,996
Likes: 0
From: Berea, OH
Year: 1998
Model: Cherokee
Engine: 4.0
I'm going to try to cover this without getting too technical.
The stock exhaust is a compromise between efficiency, power and quietness and does have a considerable amount back pressure. In this case, the back pressure actually aids in quieting the engine, but decreasing the torque.
Back pressure is not an engines friend as it causes hot exhaust to remain in the engines exhaust port for a longer period of time. Granted, it just for a fraction of a second, but that's all it needs.
A well balanced exhaust system will have a 'tuned' exhaust manifold, exhaust pipes of sufficient diameter to maintain exhaust velocity and cat and muffler with minimum restriction.
A 'cat back' system generally refers to the components after the catalytic converter. Reducing the restrictions of the muffler and tail pipe will improve engine torque. But, the cat still remains as a restrictive device and can be solved by replacing the stock converter with a high flow version.
The stock cat has sufficient restriction to maintain the burn in cleaning up the exhaust. This is probably more true of the '97 and newer XJs with the dual O2 sensors. However, a high flow cat is designed so that the exhaust has less restriction while doing a proper burn.
A tuned exhaust manifold is designed so that as the cylinder releases the exhaust gas it aids in pulling in the next air/fuel component, called 'scavenging'. It does this by having timed equal length exhaust tubes.
To clarify this, as one cylinder pushes out the exhaust, the next cylinders exhaust won't collide with the previous going out the exhaust pipe. For illustration, look at the 4.0 aftermarket exhaust manifold. You'll note that cylinders 3 & 4 are closer to the exhaust pipe port than 1 and 6. In a factory manifold, the exhaust is just dumped into a common pipe and the exhaust exists the best it can. With the referenced manifold, each pipe is designed in length and diameter to reduce exhaust collision and exit freely.
On the math side...once it is all said and done...the 2.25" exhaust was engineered to balance the scavenging/exhaust velocity of the 4.0 head. If you had a stroker, high flow head, I would go 2.5". However eliminating restrictions after the muffler can improve the torque curve. The problem with the stock system are the bends that were put in the downpipe, tailpipe and the restrictive stock cat and muffler. By going to mandrel bends and high flow, you will achieve the best of both worlds with 2.25 through to the muffler with all freeflowing components.
That's all I'm going to get into here. If you want to learn more here are two excellent articles (and not too complicated) that explain in detail the exhaust flow.
http://www.veryuseful.com/mustang/tech/ ... enging.pdf
http://www.bigcitythunder.com/pages/und ... xhaust.pdf
EDIT...damn second link no worky no more... :-(
The stock exhaust is a compromise between efficiency, power and quietness and does have a considerable amount back pressure. In this case, the back pressure actually aids in quieting the engine, but decreasing the torque.
Back pressure is not an engines friend as it causes hot exhaust to remain in the engines exhaust port for a longer period of time. Granted, it just for a fraction of a second, but that's all it needs.
A well balanced exhaust system will have a 'tuned' exhaust manifold, exhaust pipes of sufficient diameter to maintain exhaust velocity and cat and muffler with minimum restriction.
A 'cat back' system generally refers to the components after the catalytic converter. Reducing the restrictions of the muffler and tail pipe will improve engine torque. But, the cat still remains as a restrictive device and can be solved by replacing the stock converter with a high flow version.
The stock cat has sufficient restriction to maintain the burn in cleaning up the exhaust. This is probably more true of the '97 and newer XJs with the dual O2 sensors. However, a high flow cat is designed so that the exhaust has less restriction while doing a proper burn.
A tuned exhaust manifold is designed so that as the cylinder releases the exhaust gas it aids in pulling in the next air/fuel component, called 'scavenging'. It does this by having timed equal length exhaust tubes.
To clarify this, as one cylinder pushes out the exhaust, the next cylinders exhaust won't collide with the previous going out the exhaust pipe. For illustration, look at the 4.0 aftermarket exhaust manifold. You'll note that cylinders 3 & 4 are closer to the exhaust pipe port than 1 and 6. In a factory manifold, the exhaust is just dumped into a common pipe and the exhaust exists the best it can. With the referenced manifold, each pipe is designed in length and diameter to reduce exhaust collision and exit freely.
On the math side...once it is all said and done...the 2.25" exhaust was engineered to balance the scavenging/exhaust velocity of the 4.0 head. If you had a stroker, high flow head, I would go 2.5". However eliminating restrictions after the muffler can improve the torque curve. The problem with the stock system are the bends that were put in the downpipe, tailpipe and the restrictive stock cat and muffler. By going to mandrel bends and high flow, you will achieve the best of both worlds with 2.25 through to the muffler with all freeflowing components.
That's all I'm going to get into here. If you want to learn more here are two excellent articles (and not too complicated) that explain in detail the exhaust flow.
http://www.veryuseful.com/mustang/tech/ ... enging.pdf
http://www.bigcitythunder.com/pages/und ... xhaust.pdf
EDIT...damn second link no worky no more... :-(
CF Veteran
Joined: Sep 2011
Posts: 10,447
Likes: 0
From: Frederick, MD
Year: 1989
Model: Cherokee
Engine: 4.0
I'm so pissed. The cop that tried to arrest me for my "gun" made me put my doors back on, since I was on the school parking lot, and wouldn't let me leave until they were on, so I put them on, parked on the street and took them back off. She yelled at me again so I left.
