Maryland Cherokee Club
CF Veteran
Join Date: Feb 2012
Location: Bowie, MD
Posts: 2,716
Likes: 0
Received 2 Likes
on
2 Posts
Year: 1999
Model: Cherokee
Engine: 4.0L
Such a rebel LOL
CF Veteran
Join Date: Feb 2012
Location: Forest Hill, Maryland
Posts: 6,468
Likes: 0
Received 18 Likes
on
14 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L
at that point, just as long as you have mirrors (driver side and rear view) tell them that it is not illegal and they can't do anything about it.
CF Veteran
Join Date: Sep 2011
Location: Frederick, MD
Posts: 10,447
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by kuzican
at that point, just as long as you have mirrors (driver side and rear view) tell them that it is not illegal and they can't do anything about it.
CF Veteran
Join Date: Mar 2009
Location: Berea, OH
Posts: 7,996
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0
Always a good call when speaking with cops.
"Hey officer, you're ignorant, stay the "F" away from me....you can't do squat...nanny nanny boo boo"
CF Veteran
Join Date: Nov 2010
Location: glen burnie md
Posts: 5,151
Received 0 Likes
on
0 Posts
Year: 2000
Model: Cherokee
CF Veteran
Join Date: Sep 2011
Location: Frederick, MD
Posts: 10,447
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by gone4x4
--might not be sage advice, i think him just leavin was the smartest thing, he is though, a marked Jeeper!!
CF Veteran
Join Date: Jan 2012
Location: Baltimore, MD
Posts: 8,272
Likes: 0
Received 1 Like
on
1 Post
Year: 1999
Model: Cherokee
Engine: 4.0 I6 HO
Originally Posted by my89xj
I'm printing out were it says that and talking to her about it tomorrow. And ill have no exhaust on tomorrow since my magnaflow cat just came in the mail
CF Veteran
Join Date: Feb 2012
Location: Sykesville, Md
Posts: 2,961
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2000
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... :-(
Ah... tis a shame I graduated... had a blast while I was there
CF Veteran
Join Date: Feb 2012
Location: Laurel, MD
Posts: 2,574
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L
post the link once you find it please
CF Veteran
Join Date: Feb 2012
Location: Laurel, MD
Posts: 2,574
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L
CF Veteran
Join Date: Sep 2011
Location: Frederick, MD
Posts: 10,447
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by a_shirey
you're such a terrible student. better than ripping down speed cameras like at my school or shooting someone...
Seasoned Member
Join Date: Aug 2010
Location: Ashburn, VA
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0
Originally Posted by mikefrost
Here's a set of 2x4 sliders I just built. Getting ready to Raptor line these
CF Veteran
Join Date: Feb 2012
Location: Bowie, MD
Posts: 2,716
Likes: 0
Received 2 Likes
on
2 Posts
Year: 1999
Model: Cherokee
Engine: 4.0L
CF Veteran
Have yet to meet one person in my life that I was ever worried about. That is not the reason I hold back/filter my thoughts on this here forum. For the multitude of idiots that are here, there is a few that are worth listening to and would like to stick around, (not be banned), and hear what they have to say.