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  #1  
Old 03-06-2002, 12:10 PM
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Dome Dome is offline
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Whats the conensus?? I'm going to be replacing my exhaust system in the very near future. Oh, and I have a 2bbl 360 if that makes a difference.
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Old 03-06-2002, 01:34 PM
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Hi Adam...
I went with 2.5" and a 50 series Flowmaster and am quite happy.
The 3" would look cooler, but the gain would not be noticeable on a stock engine. I know there is someone here that went 3" but said that it got really tight going over the rear axle. Your SOA might alieviate this though. A friend of mine put a 3" 50 series Flowmaster on his Dodge p/u and it was noticibly quiter than mine. We figured that the larger pipe was slowing the exhaust pulse down.

$.02 ?

kris.
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http://www.ifsja.org/forums/vb/showthread.php?t=83102
http://www.ifsja.org/forums/vb/showthread.php?t=97262
http://www.ifsja.org/forums/vb/showthread.php?t=104163
Theres more but that should get you started

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  #3  
Old 03-07-2002, 11:06 AM
mahlmann mahlmann is offline
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For the kind of low revs our FSJ's crank, I doubt that the 3" system would provide any measurable benefit over a 2.5" system. Now, bragging rights are another area and 3" just sounds better than 2.5"!

People are usually going to tell you they like whatever they have or did. I've got 2.5" systems on my 360CID Waggy and my 402CID 400HP Chevelle. I don't think either one is limited by the performance of the exhaust system.

-Mike A.

'87 Grand "Steel Brick"
Sunnyvale, CA
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  #4  
Old 03-07-2002, 02:56 PM
Joker Joker is offline
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I just went with 3' with Flowmaster and where it sounds great I doubt it improved my performance whole lot versus 2.5. But still it sounds aewsome and it gives it the "Big Truck" look. In my case the cost wasn't much more going with the 3 in. Thats just my 2 Abe's worth.
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  #5  
Old 03-08-2002, 01:20 PM
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ArtsiFrtsi ArtsiFrtsi is offline
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Even though I can't compare my performance to a stock motor in my rig, I do like the dual 2.5 inch exhaust. It goes to a dual in, dual out Flowmaster muffler, and is quieter than the exhaust in wifies Chero... until I hit the gas!
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  #6  
Old 03-08-2002, 03:47 PM
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blt2krl blt2krl is offline
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I like the 3in I just got on my rig. No complaints as far as performance losses in comparison to the duals I had removed.
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  #7  
Old 03-09-2002, 10:05 PM
Dive 30 Dive 30 is offline
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I went from Headers (Hedman $99) to 2.5" flex pipes ($9.00 Autozone) and 2.5" cherry bomb glass packs ($15.00 Autozone)to a custom bent single 2.5", no cat, to a 14" Super Turbo. The guys at the shop (good bunch too, do lots of custom work) said that on the 360 a 3" really wouldn't gain me that much. I love the way mine sounds (especially the look on the unsuspecting punk SUV owners that try and beat me off the line) when I romp on it, the exhaust roars and I chirp the rears off the line. It is a loss in overall performance from my improvised (though audibly kick a$$ loud, cool and intolerable) exhaust. Mine cost $250.00 . . . kind of pricey.

Adam . . . I would talk to Ken's Muffler on North College. They usually pitch some attitude, but they make excellent systems for a fair price. They just initially try to talk you out of a custom set-up.
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  #8  
Old 03-11-2002, 10:23 AM
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Lindel Lindel is offline
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You certainly aren't going to gain enough using a 3" system to justify the cost, over a 2.5", or even a 2.25" system, especially with duals.

With a single, the 2.5 would be sufficient, and cost a lot less than the comparable 3" system would.
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  #9  
Old 03-11-2002, 10:28 AM
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Remember, the road to torque, which is what we want for off road, and towing, is to keep the gasses flowing at the highest possible speed, and a relatively "smaller" intake/exhaust will do that for us.

By smaller, I don't mean to the point that the engine gets choked, but a 2.5" single, or a 2.25" dual system is all that's necessary. I don't think that bumping up one more size on either will hurt, at least nothing aside from the pocket book.
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  #10  
Old 03-11-2002, 10:38 AM
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I have to disagree on the cost issue, at least in my area. The whole 3 in system cost $270 a 2.5 cost only $240. Of only a savings of 30 dollars, I decided to go ahead and do the 3in. The only other reasoning I had was that since the whole system had to be built and bent at the shop and all the bends would be at about 2.5 in. I thought it better to start out with the larger diameter. Like I said before I had 2.25 duals and there was a significant gain going to the 3in. I'm not advicating that 3in is the only and ideal way to go. I'm just stating I'm happy with the results I have obtained.
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  #11  
Old 03-14-2002, 12:46 AM
rigger rigger is offline
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i love my 3" it just sound sweet
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  #12  
Old 03-14-2002, 11:46 AM
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Millerluck Millerluck is offline
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I was recomended 3" by Thorley.

As far as price I know the guy at the muffler shop.

And yes I did drive right infront of the police station with open headers to drop it off.

The sound is sweet with a Flowmaster 50! Great rumble to it when you get on it.


Later

Larry Miller
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  #13  
Old 03-17-2002, 05:43 AM
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Cool

well with all the rocks iv gone over having a madrel bent $$$ ex system that i wood ahve to repair over n over , was not the ticket.

sooooo im using the jc whitney bendable stuff and have been for 9 years. ez to fix and rebend out of the way of this part or that part.

im running dual 2" with equal length pipe b4 and after the muffs. 2" is small, but it slides over the leeder pipes descending from the OE ex manis.

100$ for 25' of tubing, 40$ for the muffs, 20$ for clamps and such.

one thing tho...the dual system i installed to replace the single system i had b4 of the same size/material is much louder. y wood the duals be louder than the single??
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  #14  
Old 03-18-2002, 04:38 AM
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Lindel Lindel is offline
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Ken, it's probably as much the quality of the pipe, as anything else. I've had duals on hipo cars, that weren't as loud as the single with glass pack on my Cherokee.

Then again, the exhaust on my Chero is a real hodge podge at the moment. I will be fixing this in the near future.
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  #15  
Old 03-23-2002, 12:33 AM
243 243 is offline
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Take a look at the cross sectional area of typical straight pipe used in exhaust systems:

2" = 3.14 sq.in. Dual = 6.18

2.25" = 3.98 sq. in. Dual = 7.96

2.5" = 4.91 sq. in. Dual = 9.82

3" = 7.07 sq. in.

A dual 2.5" has greater cross section area than a single 3" and not by a wide margin. A single 2.5" is has a little more than half the cross sectional area of the 3".
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  #16  
Old 03-23-2002, 04:21 AM
81wag phil 81wag phil is offline
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I like the slow rumble from the three inch, I ussually get the
"MAN it sounds like it can go anywhere!" and I reply
"It does!"
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  #17  
Old 03-24-2002, 09:02 AM
Weelspin Weelspin is offline
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Since I hit another 3-4 message boards with this.... I'll hit this one as well.... I have the 258 with a manual. I needed to replace mine due to a water hole and a Kia Sportage... anyways, I went with 2 3/4 coming off the manifold and went into 3" from the cat all the way back out the right side behind the wheel. Granted, it's only a single pipe so I didn't lose the torque and I feel I've gained a little "go" by doing it. It may be the fact my OLD cat was 22 yrs. old and probably was breaking down..... don't know. But there ya go! Oh... and the 36" glass pack sounds sweet too.... [img]tongue.gif[/img]
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  #18  
Old 03-27-2002, 06:20 AM
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i am very happy with my 2.5" single, magna flow muffler and no cat. deep rumble, not very loud

benjamin
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  #19  
Old 03-29-2002, 10:13 AM
jeepbob jeepbob is offline
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I run 2.25 duals which seem to work well and sound good. I just not want to do this install myself as it was a real b*tch.
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