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Pittdawg
Dodge Dakota
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10/21/2002
22:39:46
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 Subject: 4-tube headers for the 4.7?
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From everything I've read on here headers are a waste for the 4.7. However, upon browsing the kenne-bell site (only if a supercharger was as cheap as headers...) I noticed that "4-tube" headers produced 12 rear-wheel dyno tested horsepower. My question is, anybody know what headers these are and was there test vehicle one with the pre-cats?
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cudashoe
DakotaEnthusiast
10/22/2002
14:55:40
| RE: 4-tube headers for the 4.7?
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Its not that they are a waste, they do give more power. The argument is that the gains arent worth the money. Kind of like 4.7 throttle bodies, the gains are so small compared to the price.
2000 4.7 5- speed, 1989 Shelby #799 White
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Demon Dakota
DakotaEnthusiast
10/22/2002
15:18:42
| RE: 4-tube headers for the 4.7?
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I think that all of the mods for the 4.7L are worthy, but are much better when combined with other mods. If you add a TB, then you had better add headers and a higher flowing exhaust system to help with the higher incoming airflow. The TB by itself will not produce that much of a gain overall without other mods. There are no miracle mods (other than superchargers and turbochargers).
K&N Drop in AF
True Dual exhaust and removed third cat
HO Cams & HO Intake
Modified TB
Autolite 3923 Plugs
TPS @ .76 VDC
IAT Adjuster Mod
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Pittdawg
Dodge Dakota
JOIN HERE
10/23/2002
00:48:01
|  RE: 4-tube headers for the 4.7?
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Message:
someone informed me the headers the website referts to are kennebell's but I can't find them on their website anywhere (or anywhere else for that matter). Anyways, I have another question, I've heard many horror stories about gaskets becoming unsealed on headers and this and that leaking, is the common with all headers or are these stories based on shammy products?
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D
GenIII
10/23/2002
13:30:28
| RE: 4-tube headers for the 4.7?
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Message:
they are kenne bell headers. if you get an info
package from them, they list all the part
numbers and dyno results etc.
the part number is D4004-4.7 they work for
2000 models only and will not work on the
Grand cherokee, only dakota and durango.
they claim 15HP (doubt it unless you are
supercharged and 25-30 ft lbs of TQ) the
stock manifolds look very restrictive in
comparison to the KB headers, but like I said
unless its supercharged I doubt you will
notice much, if any gains. their price list says
"check availability" under the price column, so
I would say that they havent been released yet
and are probably still in testing, or waiting for
CARB approval.
2001 4.7 CC auto
shaved door handles & tailgate
welded Sir Michaels roll pan
DJM drop 3/6
airaid intake
180 stat, ported-polished TB
Dynomax 3" dumped carsound cat
HO cams/manifold, Sure Grip & 3.92's collecting dust!
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Zach
Dodge Dakota
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10/23/2002
16:54:47
|  RE: 4-tube headers for the 4.7?
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Message:
I just got done talking with an exhaust expert yesterday, because I was interested in the exact same questions you're asking. He saw me coming in and had an immediate answer to my questions. "Don't get headers!" He blatantly said this because when you install headers for a 4.7 MAG, you're running a huge risk of blowing your gaskets and cracking your manifold.
For more performance, just go with a cold air intake and a throttle body spacer. At $500+ for headers, I wouldn't run the risk bud.
Hope this helps!
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Canucker
Dodge Dakota
JOIN HERE
10/23/2002
17:05:56
| RE: 4-tube headers for the 4.7?
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blowing your gaskets and cracking your manifold!?
that's the most rediculous thing I've heard (even though I can't even spell the word)!
Does he mean you'll crack the exhaust manifolds that you just took off because you put headers on? ... how does he crack them, drop them on the floor? (hopefully they hit his foot on the way down)
Or does he mean you'll crack the intake manifold? you know, the big black plastic thing ...
I'm killing myself laughing here cause I don't know which is funnier ... but he's an 'expert' eh? Good thing he recommends that TB spacer though.
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CThomp
Dodge Dakota
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10/24/2002
09:30:37
| RE: 4-tube headers for the 4.7?
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I agree with demondakota on combining mods. I expected to see miraculous gains with the 68mm Fastman TB and 360intakez but didn't end up experiencing any of that until I put on the carsound cat. That made a huge difference. I should see even more once I put a better muffler on. I'm not expecting massive gains but even smoother response and acceleration are gains in my book.
I am curious as to how the Kenne bell headers were tested. If that 12h.p. was made on a stock 4.7L....thats not to bad at all.
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sandman
Dodge Dakota
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10/24/2002
20:49:59
|  RE: 4-tube headers for the 4.7?
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I think you could port the manifolds and then extrude hone them if you realy need more flow. If you plan on turbo chargeing the cast iron manifold will hold up better then anything else. I really want headers talk someone into makeing cast stainless steel or even just plain steel tubular header/manifold. The tubular manifolds are just like tubular headers only tougher and more durable due to cast construction. You might have seen these on some HD 454's used in medium duty and motor homes based on GM truck chasis. Alot of guys retrofited the plain jane factory one for these improved factory pieces. GM even made them out of SS. The list for $385.00 dealer cost new but alot junk yards have them for about $80.00 in my neck of the woods. Most headers do ot last long before they crack at the flange or warp at the flange. Headers also saturate your engine compartment with alot of extra heat. So if you really need the flow go for it but if you do not need the flow I would save your money and buy the HO cam's and HO intake manifold instead!!!!
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4.7L Jeep G.C
Dodge Dakota
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12/29/2004
17:12:17
| RE: 4-tube headers for the 4.7?
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Message:
Are there any headers for the 4.7 grand Cherokee out there? I have searched all over the internet and cant find any. Reason being is that I have ordered a KB supercharger for my jeep and they say that headers and a exaust system will provided alot more power from the supercharger. I have heard that you could expect 50+ hp with headers and exaust. Any help would be appreciated.
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WestTX47
Dodge Dakota
JOIN HERE
12/30/2004
17:11:19
| RE: 4-tube headers for the 4.7?
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Well, this is not what I want to hear. I just bought a set of Gibson headers for my 4.7. Hmm, how much are the HO Cams and Intake?
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01Motorsport
Dodge Dakota
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12/30/2004
23:31:42
| RE: 4-tube headers for the 4.7?
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The factory 4.7 exhaust manifolds flow to within 2% of headers. HO cams are about $130 each with a good deal (20% off, etc.). A pre-2003 non-HO intake favors low-end torque, the HO favors higher revs.
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GraphiteDak
GenIII
12/31/2004
00:29:58
| RE: 4-tube headers for the 4.7?
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Message:
I bet you a set of FULL LENGTH headers coupled with dual cats, etc will do wonders compared to the stock manifolds and y-pipe.
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Troller
Dodge Dakota
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12/31/2004
09:01:19
| RE: 4-tube headers for the 4.7?
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"The factory 4.7 exhaust manifolds flow to within 2% of headers" blah blah blah! Here we go again! 2% of what headers??????? People quote this all the time! Where did you get this information from??????? Gibson short tube headers produce between 8-12 RWHP! http://www.gibsonperformance.com/exhperf.asp
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Rob C
Dodge Dakota
JOIN HERE
12/31/2004
13:01:05
| RE: 4-tube headers for the 4.7?
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You're not going to find any headers for the 4.7 WJ, no one makes them because there isn't enough room. If you're worried about the exhaust being restrictive, just make sure you've got a good free flowing exhaust behind those exhaust manifolds.
Troller, you're flaming people for quoting the 2% statement then you quote a manufacturer's website horsepower gains. That's like quoting something you saw on a TV commercial. A website advertisement isn't fact, a dyno printout is. Do you have the Gibson headers? Did you dyno your truck before and after you installed the headers?
WestTX47, http://www.buymopar.com/store/jeep.html This place has the cams for $105 ea.
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