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Unread 01-31-2012, 11:33 PM   #1
lvngtheJEEPlife
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2001 WJ 
 
Join Date: Aug 2011
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Exhaust systms

I have a 94 ZJ with the 4.0, i strapped on a magna flow muffler on a eliminated the Cat, but i left the stock pipes. Will this hurt my performance? The stock pipes are really small, so is the new muffler doing nothing because of too small of pipes? thanks!

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Unread 01-31-2012, 11:48 PM   #2
stormer1092
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I'm no performance pro but a more flowing pipe is more than likely helping same with eliminating the cat and replacing it with a test pipe. I heard somewhere someone correct me if i'm wrong but a 2-3/4 pipe is the best size for the 4.0. I believe stock is 2-1/4.
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Quote - I currently have this set up with some ok shocks. Mine rides stiff but its not completely unbearable. My rear end is what kills me more than anything. Signed - Okie_Rider
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Unread 01-31-2012, 11:59 PM   #3
zander21510
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...btw eliminating the cat is illegal by federal law...I see closure ahead!

Anyways, from what I've read you need a little bit of backpressure on the 4.0 to have it reach its full potential...but keep in mind it just wasn't meant to go fast lol. They make hi-flow cat's and mufflers.

PM Kolak, he's the man to talk to with exhaust.
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Unread 02-01-2012, 12:05 AM   #4
stormer1092
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Quote:
Originally Posted by zander21510 View Post
...btw eliminating the cat is illegal by federal law...I see closure ahead!

Anyways, from what I've read you need a little bit of backpressure on the 4.0 to have it reach its full potential...but keep in mind it just wasn't meant to go fast lol. They make hi-flow cat's and mufflers.

PM Kolak, he's the man to talk to with exhaust.
hey now he installed a test pipe.
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Quote - I currently have this set up with some ok shocks. Mine rides stiff but its not completely unbearable. My rear end is what kills me more than anything. Signed - Okie_Rider
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Unread 02-01-2012, 03:53 AM   #5
Buzz98zj
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Can't believe this wasn't shut down yet. Lol we don't discuss emissions here.
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Unread 02-01-2012, 06:30 AM   #6
ratmonkey
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put a cat back on it. no performance gain from it being gone, it's illegal, it's bad for the planet.
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'97 zj 5.2, some stuff, some other suff, and some things that even work sometimes.

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exhaust , exhaust system , muffler replacement , performance improvements

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