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D Denney
Dodge Dakota
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3/31/2002
22:06:39
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 Subject: 4.7 mods worthless
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is everyone on this board in denial,we all know that an aftermarket exhaust hurts the performance of the 4.7. I put a flowmaster 50 on mine and right away noticed the drop in throtlle response. I posted my problem on this board and was told since i was letting more air out i needed to get more air in.Ok so now i put a cold air system on my truck and im back to square one.Doesnt make a whole lotta sense to spend 350.00 dallars for no improvement in performance.
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CW
GenIII
 
3/31/2002
22:18:34
|  RE: 4.7 mods worthless
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Don't tell that to my truck that just ran a 14.76 at 3000 feet.
2001 4.7 RC 5sp 3.92 LSD
Click on thumbnail for mods.
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Quad47
Dodge Dakota
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3/31/2002
23:49:41
|  RE: 4.7 mods worthless
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I'm with you CW, I went with a Gibson 3" single-swept cat-back, airaid cold-air kit, and the tb spacer. I don't have the time slip to vouge for it, but I can feel the difference. Am going to Lowes in the a.m. to get the parts to finish off the cold-air package. Am going to stop by a couple of exhaust shops and see about getting a stretch of 3" stainless for a bit of a "high-dollar" look. Figured that it will look real nice if polish it out. Will let you know how that works.
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Jon H.
Dodge Dakota
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4/01/2002
00:04:46
| RE: 4.7 mods worthless
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Message:
Thats really odd...I spent about $380 total for intake and exhaust and now my truck sounds mean as hell and gets better gas mileage...to me it is paying for itself
P.S. an initial muffler only drop in low end torque doesnt mean it is slower in the higher rpms. Get a free flow cat or cut that s.o.b. and feel/hear the new power.
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QUADMAN
GenIII
4/01/2002
01:36:54
| RE: 4.7 mods worthless
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Sorry Denney but I can definately tell a difference in my quad since I put the flow 40 and K&N in. Especially from 50 to 100 mph. I can't really tell a loss in low end cause now it will lay down rubber with the 33's, before it just chirped a bit.
YOUR ONLY WORTH WHAT YOU OWE!
3" Body Lift, 33x12.50x15 MTR's, K&N Drop-in, Flow 40 with stainless duals, Procomp Prerunner Lightbar, and many more to come!
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Jon H.
Dodge Dakota
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4/01/2002
17:24:09
| RE: 4.7 mods worthless
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Oops...my bad...more like $280 total. Definitely feel more top end coming out of the beast.
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sandman
Dodge Dakota
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4/01/2002
22:05:43
| RE: 4.7 mods worthless
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While I am all for more performance I am saveing up so I can do some serious work on this thing. I want to get some de-stroked(lower wrist pins) pistons in about 8.5:1 with the rings lowered and more skirt and forgded. I want more aggresive cam grinds, higher flowing injector, reflashed PCM and a set of twin seq. turbo's hanging from each manifold! I would like to see a redesiged intake manifold with longer runners with the feed up front instead of at the rear to make force feeding a bit easier. Higher strength valve springs and piston oilers. The lower half of this engine is GREAT!!! The heads are realy realy good!! The intake manifold is ok for a truck but is not designed for high RPM use. The pistons are junk, the cam are too mild and they ECM is going to be a real limiting factory in stock trim! I can not wait to save up enough money to realy start playing with this engine!!!!! Has anyone tried a seperate fuel computer for this engine yet? Does anyone know where the primary and secondary harmonics on this engine realy get out of control? I would like to have leach push the rpm limit up and use the most aggressive fuel map in the eproms programing as baseline and right some new more agressive one that respond to boost pressure and engine vaccum but there are to many things that I do not know about this engine : what rpm do the valves start to float, what rpm creates destructive crank harmonics........ Has Bernd finished engine mapping with his kit our 4.7L Daks yet??? I am also woudering how much extra space the eprom has and if there are any extra input and outputs on the conector. It would be great if the boost control could be intergrated into the stock ECM!!!!
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Duner
Dodge Dakota
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4/01/2002
22:45:54
| 4.7 mods not all worthless
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Sandman - you don't want much do you? hahaha
You are talking about having everything but the block manufactured from scratch. That would be very cost prohibitive. A 380 hp crate motor and a new wiring harness would probably be more effective. I have a sneaking suspicion that if and when the 5.7 engine hits the market in a Dakota that all thoughts of a project of this scope would be forgotten.
Also, what you actually want for higher rpm power will be shorter runners. The runners on the stock beer barrel intake are very long already. Shorten them and you will lose torque though.... it's a tradeoff however it's set-up. Small displacement engines need help in the torque department.
The engine can definately use a set of more agressive cams. My stock valve train has seen upwards of 7000 rpm without any sign of valve float, although with such conservative cams it should be able to rev to the moon without any probs.... if it could make enough power to rev that far. Not having pushrods helps with that quite a bit.
The stock PCM programming already provides too much fuel in the upper rpm ranges. My engine responded very favorably (more hp) to less fuel when it was N/A. Taking away fuel increased the off idle throttle response as well as extended the rpm range and power production, adding fuel worked more like a soft rev limiter and made the dyno curve fall like a rock past 5000 rpm. The latest dyno chart before going to the turbo had peak numbers of 242 rwhp and 322 ft-lbs rwtq.
As far as destructive crank harmonics? Your guess is as good as mine. Hopefully I will never find out either! I have no idea what the actual hp/tq numbers are with the turbo system in place but the online calculators are suggesting something like 400 hp and 500 ft-lbs of torque.
I plan on experimenting with the SplitSecond controller for both the fuel and ignition timing. The addition of a 2.5 bar MAP sensor should allow for control of the fuel system under boosted conditions. I hope to find out fairly soon...... currently economically challenged (broke).
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Demon-Xanth
Dodge Dakota
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4/02/2002
09:03:27
| RE: 4.7 mods worthless
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I've been noticing that to get some improvement, if you do something to the bottom, you gotta free up the top to compensate. I probably lost a few HP when I put my muffler in, but I expect to make it back when I install an intake kit. (waiting for the cash flow to come around)
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Wes
GenIII
4/02/2002
12:51:01
| RE: 4.7 mods worthless
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I agree- the exhaust mod is worthless. To much loss in low end for an everyday driver. Its good for high rpms, but never there unless you are racing.
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conig
Dodge Dakota
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4/02/2002
14:43:26
| RE: 4.7 mods worthless
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remove your cat then say exhaust is worthless. freeing up restriction after the actual restriction is a waste of time think of a coke bottle you can make the bottom of the bottle as big as you want but it won't flow faster out the top. just my 2cents.
i may even get headers now since the ownly person I saw dyno with them that had some sort of cat mod was duner. my mods are almost identical and I don't think I have 245rwhp. but I will get a dyno pull shortly.
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fillupd
Dodge Dakota
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4/02/2002
17:33:26
| RE: 4.7 mods worthless
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I have an 01 4x4 4.7 with a K&N DIY intake. When I am at around 70 mph and want to speed up to 80 with the cruise button, it downshifts to get up to that speed. Sometimes on a hill it will do the same. Is this normal, will a flowmaster muffler help?
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ZenDak
Dodge Dakota
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4/02/2002
17:52:01
| RE: 4.7 mods worthless
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I just want to throw this out there...
On these motors (4.7), I've heard some say that freeing up the exhaust (less back pressure), might cause you to burn up your valves. Is this true?,,has this ever happened to anyone?
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sandman
Dodge Dakota
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4/02/2002
19:07:38
| RE: 4.7 mods worthless
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Dunner I just want to treat this motor the same way I would a Honda or a Toyota. I realy like this engine!I even like the transmission for the most part! I must admit that I would like a bigger engine in a truck if I was going to tow alot but this engine is a fine engine. I still think that it would make the perfect engine for a RWD car slightly larger then a Neon but smaller then a Mustang. Either front engine RWD or mid-engine RWD. It would sell like hot cakes and it would not be competeing with the Viper at all. I also think that DC could offer a supercharged version of this engine in our Dak's with a 6 spd manual trans as the RT. I know alot of guys probably want to know what I am smokeing!!! The only compalint I have with this engine from a stock durability standpoint is the pistons the rest of the engine is great.P.S. I was looking at the pistons in the North Star series and the Vortec 4200. They both use the same style of piston as our trucks. The north star motors get real thirst for oil around 80,000 miles. I am thinking that our 4.7 will probably get thirsty around this time as well!
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Hersbird
Dodge Dakota
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4/02/2002
19:54:50
| RE: 4.7 mods worthless
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Is it the pistions that cause the oil usage in the Northstars? I thought they really started having problems with all of the seals at that point and leaked oil more then burned it. If the northstars burn oil I would think it to be the problem of valve seals and guides, as is the case with most OHC motors after 100-150,000 miles. The Northstar is still one of my favorite motors. The first time I ever drove a STS (an older, more brutal, 95 model) I was really impressed. Motor trend got a 14.8 1/4 mile with one of those back in 95 and thats one heavy car with FWD. Now I want a 98 or 99, more cushy, STS as my 3rd car so I can hot rod the Dakota more.
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handi2
GenIII
4/02/2002
20:20:27
| RE: 4.7 mods worthless
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Message:
As far as the Northstar engine is concerned mine doesn't leak or use any oil at all with 47,000 miles. But I have heard of the leaking problems.
It is a Cadillac Allante' 1993. You probably know it is a shortened Eldorado Convertible (2 seater). They were made from 87 to 93 with the 93 model having the Northstar engine. They were a joint effort w/Pinninforino of Turin Italy. The body and interior by Pinninforino and the car by Caddy. 300 hp and allot of fun w/the top up or down. It's my Cadillac Corvette..!
http://photos.yahoo.com/handi254310
2002 Quad Cab SLT Plus 4.7 Every Available Option
Access Tonnoue Cover/Bedrug/360 Air Intakez/Jet Stage 2
180 Robertshaw/Roadmaster Active Suspension
Street Scene Grill Inserts
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Hersbird
Dodge Dakota
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4/02/2002
23:49:50
| RE: 4.7 mods worthless
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I didn't know the Allante ever had a Northstar, that must be pretty quick in the smaller body! I could never get an Allante cause I have this episode of "Married with Children" stuck in my head every time it's name is mentioned. Christine Algulira (SP?), (like perfect spelling is common in my posts!) saying, "Presenting the new Allante!" over, and over, and over...
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ed
Dodge Dakota
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4/04/2002
04:05:14
| RE: 4.7 mods worthless
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01 QC 4x4 4.7L
I think the best mods for a 4.7L are an intense performance 3" Z Tube w/9" Pro Flo Filter and a flowmaster 40 series w/ 3" custom catback. I noticed an immediate and very noticeable increase in HP and TQ. Both the stock dodge intake and exhaust are very restrictive and the proper setup can really bring the little 4.7L to life.
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handi2
GenIII
4/04/2002
07:39:45
| RE: 4.7 mods worthless
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Hersbird,
The last year Allante' came with the Northstar V-8. It's a beautiful engine, if you think of engine's in that way. I only drive it a few miles a month and it has never been driven in the rain. The car has only 47,000 miles. That's not bad for a 93. I usually only use for "top down" driving around the beach, which is my neiborhood. I'll get some pics included with my others posted at Yahoo.
http://photos.yahoo.com/handi254310
2002 Quad Cab SLT Plus 4.7 Every Available Option
Access Tonnoue Cover/Bedrug/360 Air Intakez/Jet Stage 2
180 Robertshaw/Roadmaster Active Suspension
Street Scene Grill Inserts
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Hayden
Dodge Dakota
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2/18/2013
16:23:55
| RE: 4.7 mods worthless
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Message:
I've had people tell me these motors like to drop valve seats,
anyone had any problems with this?
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daddio
Dodge Dakota
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2/19/2013
13:34:53
| RE: 4.7 mods worthless
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You can search on here but that's the first I ever hear of it. Those must be Chevy guys feeding you a line.
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