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Unread 05-01-2013, 05:29 AM   #31
Matt1981CJ7
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Quote:
Originally Posted by jeepdaddy2000 View Post

Personally, I prefer stock manifolds with either a dual system or a larger (up to 3") single, coupled to a free flowing muffler(or glass pack if you like more sound), plumbed out the back. I like to have a compression flange installed by the transmission, allowing the pipe to be broken for easier access in case the trans needs to be dropped (not necessary, but it usually helps). These systems are solid, long lasting, and pretty much maintenance free.
Jeepdaddy,

Something like this?

Matt

exhaust1.jpg   exhaust2.jpg   exhaust3.jpg  
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Unread 05-01-2013, 06:46 AM   #32
swatson454
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This forum is more-deeply entrenched in manifolds and the proper amount of back pressure than it was ported vacuum being "correct". With this kind of resistance to something that's been common knowledge for decades, I've got nothing further to offer here.

I've done it on my own vehicles and plenty of others; some bone stock, some pretty wild, heavy 4x4s to semi-gutted bracket cars, too many times to continue to believe this old stuff.

Carry on, gents


http://www.shop4exhaust.com/t-Stock-...t-Headers.aspx

Edit: OP, if you can find long-tubes with 1 1/2 primaries and 2.5 inch collectors, your torque will be further improved. I don't know if anyone even makes them but it's worth a look.

Good luck!

-S
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Unread 05-01-2013, 06:57 AM   #33
Matt1981CJ7
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I'm not sure where anyone has mentioned "back-pressure", but I know that's one of your pet peeves.

I also don't think anyone has disputed that headers increase performance.

The question is how much performance is gained, and is it enough to justify the well-documented problems with headers? I think many of us feel the answer is "no". For some it may be a resounding "yes". I'm pretty sure the OP asked for all opinions, not just pro-header opinions.

Don't get butt-hurt over nonsense, my friend.

Matt
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Unread 05-01-2013, 07:15 AM   #34
swatson454
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Nah, I'm not butt hurt.

There's some pretty shady workmanship on some headers: there's no disputing that. Just pulling them out of the box and slapping them on isn't a good idea. You need to throw a straight edge across the flange and make sure the welds aren't haywire and address any that are. I stay far away from the paper gaskets that are included whenever possible and do my best to modify the thicker, metal gaskets that are often OEM for exhaust manifolds. You must retorque the gaskets after a heat cycle or two. Then the next day and usually check them the day after. They can also dangle a lot of weight off to the side, especially fenderwell headers, so they need support out there as well. Maybe I'm just lucky but I've never had the leak issues (at least not for long) that are purported here.

It's also unwise (and unfair to the headers) to throw headers on to an already inadequate exhaust. Treat the whole thing as a system, paying attention to pipe lengths, diameters and flow for the required rpm and you'll be further ahead.

If you're 100% stock on a 304, they may or may not justify the expense. That'll be an individual opinion. Once installed, however, they'll make any other improvement you do (intake and carb, cam, etc.) provide the gain it was intended to.

You guys are 100% correct on your arguments regarding off-roading and keeping things tucked up and out of the way.


Shawn
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Unread 05-01-2013, 08:38 AM   #35
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Alex,

I just caught something. Please do yourself a favor and ditch that massive fire hazard air filter ASAP!


Shawn
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Unread 05-01-2013, 08:52 AM   #36
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Quote:
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Jeepdaddy,

Something like this?

Matt

I really like your exhaust routing. Very clean.
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Unread 05-01-2013, 09:03 AM   #37
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Originally Posted by swatson454
Alex,

I just caught something. Please do yourself a favor and ditch that massive fire hazard air filter ASAP!

Shawn
Are they really that bad? I've never used them before but I needed something small like that with my fuel filter.. What's something better to use?
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Unread 05-01-2013, 09:06 AM   #38
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Quote:
Originally Posted by swatson454
Alex,

I just caught something. Please do yourself a favor and ditch that massive fire hazard air filter ASAP!

Shawn
Thanks for catching that for me.
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Unread 05-01-2013, 09:09 AM   #39
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Are they really that bad? I've never used them before but I needed something small like that with my fuel filter.. What's something better to use?
Yeah, they're bad. I've heard dozens of horror stories and have actually seen one in person. That foam collects fumes and all it takes is a pop through the carb.

Use whatever suits your fancy just get rid of that vapor-soaked foam directly over the carb.

Sorry for the highjack.


Shawn
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Unread 05-01-2013, 09:14 AM   #40
Alex77cj7
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Quote:
Originally Posted by swatson454

Yeah, they're bad. I've heard dozens of horror stories and have actually seen one in person. That foam collects fumes and all it takes is a pop through the carb.

Use whatever suits your fancy just get rid of that vapor-soaked foam directly over the carb.

Sorry for the highjack.

Shawn
Thank you so much
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Unread 05-01-2013, 12:34 PM   #41
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I just learned something I had no idea about. When running manifolds, tying them together with a merge collector and single out is quite a bit better than going dual out. There's some good info on this site for you manifold guys.

Cheers


Shawn
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Unread 05-01-2013, 01:32 PM   #42
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I had a set of in-frame headers on my CJ7 with dual exhaust exiting out the side behind the rear wheels. Fortunately for me I did not have leak issues but did have heat issues even after wrapping the headers. I ended up putting a heat shield on my starter and it solved the problems. My 304 had a mild cam in it. As far as performance gains, since I never drove it with the stock manifolds I can't comment. All I know is that I loved the sound! The guy I sold it to drives it 4-5 days a week and the sound has gotten even better with age.

On the 304 I have in the Scrambler, I plan to go back to manifolds. Mainly due to the fact that I fell I got lucky with the headers on my CJ7 and didn't experience the common issues.
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Unread 05-01-2013, 01:45 PM   #43
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Quote:
Originally Posted by swatson454 View Post
I just learned something I had no idea about. When running manifolds, tying them together with a merge collector and single out is quite a bit better than going dual out. There's some good info on this site for you manifold guys.

Cheers


Shawn
I'm going to end up coming off as "manic" to my muffler guy. Good discussion! So running this particular collector is good for HP gain, or for any collector setup? More backpressure?
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Unread 05-01-2013, 02:08 PM   #44
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I'm going to end up coming off as "manic" to my muffler guy. Good discussion! So running this particular collector is good for HP gain, or for any collector setup? More backpressure?
From what I gathered, if you have to or simply want to run manifolds, there was a power gain by doing a 2 into 1 like Matt did, rather than duals; which is what surprised me.

Those guys are the only ones I could think of that have bothered to go the extra mile with exhaust manifolds because of so many different roundy-round classes that mandate manifolds. I have no idea why the 2 into 1 is better.

I just dug up a Vizard test on a stock 180 HP, '79 Camaro where headers with a high-flow cat and muffler was 27 hp and 31 ft/lbs better than the stock system with the torque improvement being across the board and the hp increase climbing with rpm.

Anyways, manifolds are so popular on here, we may as well try to do it right.


Shawn
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Unread 05-01-2013, 02:33 PM   #45
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Originally Posted by swatson454 View Post
From what I gathered, if you have to or simply want to run manifolds, there was a power gain by doing a 2 into 1 like Matt did, rather than duals; which is what surprised me. Shawn
I'm glad to hear my muffler guy wasn't just BSing me when he said the same thing.

Matt
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