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18:59:30 - 04/25/2024
Dakota Performance
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mcarthey
Dodge Dakota
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12/09/2003
14:01:26
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 Subject: Modifying my 5.2L?
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Hey all. This is my first post and my first look into Dakota mods. I've recently been giving some thought to buying a new chip for my Dakota. It's a '97 5.2L 4x4 with the tow package and all that is included in it. I was told that I could buy a chip to make it more efficient for towing (trans? engine?). I am still learning about all of this, but I'm hoping someone can help me out. I basically want to help the engine/trans run a bit more efficiently for towing. If I could get some more HP out of it, that'd be great. I've also long entertained the idea of a dual exhaust because I enjoy the low rumble of it. I've read a bit about duals on the forum and it doesn't sound like it's something that I can take lightly, though. Basically, I noticed there were two chips. One for stock, and one for lightly modified. I plan on making some modifications so I'd like to just buy the 2nd chip (I was looking at the chips from JET), but I'm not sure if I'd be heading off in the wrong direction. I saw that someone mentioned that it's a quick route to killing an engine when towing with the performance chips. Surely there's a route I can take to make some mods to gain HP and a new exhaust without having to worry about messing anything up?
Thanks for any help. Even some keywords to get my search started here would help.
Mark
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gen1dak
Dodge Dakota
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12/09/2003
20:46:18
|  RE: Modifying my 5.2L?
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The performance chips bump up the fuel and ignition curves. This gets more power from a given setup. These mods have been around a lot longer than the chips. It's not what the chips do, it's running the engines with low octone fuel, when the chips require high octane. What happens is that when towing, you have much more load on the engine, so they don't like the greater ignition advance, and along with the greater heat generated, they become more likely to pre-ignite, or ping as more commonly referred. This causes varying degrees of damage which is potentially devastating. That's where you have to be careful. As you mod an engine, you tend to move the power band upwards, so for towing, when coming off the line, you'll have a harder working engine unless you add a looser torque converter to allow the engine to rev into the new, higher power band.
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mcarthey
Dodge Dakota
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12/11/2003
09:28:51
| RE: Modifying my 5.2L?
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Thanks for the info about the chip. I'd rather not have it revving high the entire time I'm pulling things around. I am currently planning on adding new intake, plugs and wires, and a 180 thermo. I figure this shouldn't affect the towing capacity. It seems that the thing that will largely affect it is if I were to change out the exhaust. Is this true? I'd consider changing the throttle body and ignition if it would help much. I'm still figuring this all out and would like to make changes in stages so I don't have problems down the line.
Thanks for any pointers!
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gen1dak
Dodge Dakota
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12/11/2003
16:31:50
| RE: Modifying my 5.2L?
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I've seen several posts that talk about the loss ot torque when the exhaust is changed. In my personal experience, an improved exhaust has ALWAYS improved power from the bottom on up. Perhaps the loss of power was due to too-large a system, I don't know. Opening up the choke points is key to improved performance. Adding a new intake will drop low-end power a bit with your stock cam, but it should halp a bit on the high side. Personally, I'd start with the heart. If you're serious about a better performer, get a better cam. It's more than lift in a cam. Even the early Magnum cams are better than later models despite the same lift. The cam timing is more aggressive. A perfect match to your new intake would be the MP Magnum RT cam. It pulls hard through 6,000rpm and that is just what the better intake wants....not to mention the 318. It has a perfect rod ratio, and it loves to run. Don't skimp here. Pop for the matching valvesprings, retainers, locks, and pushrods. The package is rock solid. If, later on, you feel the need for more power, add some 1.7:1 roller rockers. If the rpm power range feels right, add some 1.6:1 roller rockers. Throw on a true-roller timing gear/chain when you do the cam. New intake? Yes. 180 thermo? Yes. Plugs? Wires? Yes. Larger throttle body? Yes. Orrr, add some 1.7:1 rockers, pray the stock springs hold up, add the intake and throttle body. It'll run a bit quicker. Might even not break a spring and drop a valve. My way costs a bit more, but it's a much better approach, with much better results. You can even add a MP computer (a good idea) for better fuel curves and tranny performance. If you don't want to run premium fuel, get a timing retard from Crane or MSD. You'll be able to limit ignition advance for running cheap gas, but you'll still have the fat fuel curves for the performance mods.
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Kowalski
Dodge Dakota
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12/11/2003
17:01:32
| RE: Modifying my 5.2L?
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The chip isn't necessesarily a bad the for towing if you're smart about it. Unlike many other mods that can make your power peakier, the chip will improve power everywhere. I have a different motor (4.7) with a flashed PCM but the principles are the simular. I only need to run premium when towing, this can mean some planning ahead. Some of the guys here don't seem to like the Jet chip, there could be some better options of chips, flashes, or maybe mopar performance computer if you look into it.
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mcarthey
Dodge Dakota
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12/11/2003
20:10:15
| RE: Modifying my 5.2L?
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Thanks for the responses and getting me to look around. I found this bit of info at KRC on their roller rocker page:
Trying to boost torque? Run with the stock cams and the 1.7 roller rockers. This does 3 things to boost power; reduces friction, adds higher lift, allowing more air into the cylinder and adds more duration (usually 2 to 4 degrees) due to the geometry, making the engine see a bigger cam than what is really in there.
The problem I have now is that I've got to sort all of this information out. I don't have any training with engine work so I'm struggling to keep this all straight. I understand the basics, but when you start talking about degrees of lift and ratios and such, I get a bit lost. I've been looking for a book for a while but they all seem a bit more than I'm looking for. I'd like to find one that explains how things work together and how changing one thing will affect the torque/hp curves and what it all means. :)
Thank goodness for the internet. ;)
Thanks again!
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slow r/t man
Dodge Dakota
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12/11/2003
22:12:34
| RE: Modifying my 5.2L?
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If you want do mods for more HP but not loose any torque I would go this route. Keep the stock intake, Get a K&N FIPK, get a larger throttle body
(big gain in torque) Get 1.7 Roller Rockers and keep the stock cam, 180 degree thermostat is a must, and get a good cat back exhaust. Also what is your axle ratio? If you can afford it put 4.10s front and rear. That wold be a towing SOB
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gen1dak
Dodge Dakota
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12/11/2003
23:50:40
| RE: Modifying my 5.2L?
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You want Mopar Performance Magnum Engines. One key thing it says is that lift equals HP. It's the duration and lobe separation that have more to do with torque. The proper combination of these parameters will boost overall power in a favorable way. Again, simply adding higher ratio rockers will boost the cam specs, but it's still a lazy cam grind. It'll be better, but still not great compared to a clean slate. Still, I know how it goes. That stuff add$ up quickly. Something is better than nothing.
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slow r/t man
Dodge Dakota
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12/12/2003
09:33:17
| RE: Modifying my 5.2L?
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I was under the understanding that sort duration cam shafts increased cylinder pressure and boosted torque. The longer you hang the valves open, the more pressure you bleed off. This is why stock cams are so conservative. They are ment to run in relitivly low compression stock motors. They are designed to idle smoothly and produce a smooth steady powerband. If you add too much duration the entire package , it will shift the powerband upwards. Almost putting a hole in the powerband. And like I've said before, its tuned for low rpm torque. You don't want that "hole" at low rpm, espesially in a heavy 4X4 truck.
I feel the stock intake really shines from idle to 4500 rpm. but..... after that its like an asthmu attack. If you must buy a new cam, buy one with short duration/ high lift, as this will yield the highes cylinder pressure/ low end torque. Now if you had 4.56 gears, a loose converter, deep breathing heads ect, ect, a bigger cam might make sence. Keep your stock cam and get Harland sharp roller rockers.
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mcarthey
Dodge Dakota
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12/12/2003
18:47:07
| RE: Modifying my 5.2L?
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I'll have to do some research to make my final decision on my mods. I might just try the rocker changes with the stock cam and see how it goes. I just want to make sure the stock components won't go out on me. Besides, there's always the issue of money. :) Oh, I've got the 3.92 gears with a LSD. Because of the tow package, I've also got all the cooling upgrades. Does this mean I've still got the 195 themostat? Is there a site that lists the standard specs on the vehicles? Throttle body size, cam lift, etc? Thanks for all the tips guys!
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gen1dak
Dodge Dakota
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12/13/2003
00:05:10
| RE: Modifying my 5.2L?
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Hey, what do I know anyway?
From the Mopar Magnum bible.....
Let's look at the various specifications in order of importance.
1. Lift: Direct effect on power, especially under .600". More lift, more power (less torque).
2. Overlap: Affects idle quality and driveability.
3. Duration: Not too useful in general. For lists under .600", the advertised duration can be useful as long as all the camshafts being considered are from the same manufacturer. If more than one manufacturer is involved, go back to item #1. Duration at fifty (actually .050") is useful in hard core, all-out race camshafts and camshafts with lifts over .600".
Of all the camshaft specifications available, lift is the one to use if test results or Mopar Performance reccommendations are not available.
That is exactly as it is stated in the good book.
It is much more than duration. A cam can be short duration, high lift (or low lift for that matter), but high overlap, which roughs up the idle, and moves the powerband up. Lobe separation is much more of a determinant in idle quality (108 tends to be rough....114 tends to be silky smooth, 110 is a good balance between the two). By adding increased ratio rockers, you increase lift, and you very minimally increase the valve opening and closeing events. However, this does not change the point relative to crankshaft degrees where the valves open and close. This what is meqant by lazy valve timing of late model Magnums.
Comp Cams is a big proponent of the "under the curve" lobe design which generates more duration @ .050 relative to gross duration, which produces more torque and vacuum without sacrificing high rpm power.
I have nothing against roller rockers, but why spend $300-$400 on roller rockers when they only act off a lazy cam? For that money, you could get the right cam with matching springs, etc, and have a solid package that you could still add roller rockers to later if you wanted a bit more top-end power?
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mcarthey
Dodge Dakota
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12/13/2003
09:54:20
| RE: Modifying my 5.2L?
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Thanks gen1dak. I don't know the extent of your knowledge but I'm sure it's greater than mine. ;) It's your advise that has had me scouring the 'net for information about cams. I have long been thinking about taking a small engine course at the local tech college, but I've been putting it off (kids). In the meantime I appreciate your input, along with everyone elses here.
My initial thoughts were that I'd like to make some external mods to at least see no *loss* in torque. I've got about 85K miles on my '97. The last couple of oil changes I've been a bit low (1/2 to 1 qt) so I've put some high mileage stuff in. That seems to have taken care of it. I was surprised to see the oil low, so I'm keeping an eye on it. Anyway, my point is that I'm starting to look into doing more work myself. I'm not sure that cam changes are something I'd tackle without some training first. It seems that as I've gotten older I haven't done any work on my vehicles. My "training" car when I was 16 (a sporty '78 Horizon) saw a lot more hood work than anything since.
I'm starting small with the changes, but thanks to you guys I'm doing the research now to make my decisions later.
Mark
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slow r/t man
Dodge Dakota
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12/13/2003
10:33:20
| RE: Modifying my 5.2L?
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Stock 5.9:
Intake- .410 lift 249* duration
Exhaust- .417 lift 269* duration
Stock 5.2:
intake- .432 lift 240* durration
exhaust- .432 lift 248* durration
well here all the stock cam specs
when you refer to the stock cams being lazy you must be talking about when the valves open and close in relation to degrees of crankshaft rotation
I cannot find this information, I'll try to do some research on it. We cant call them lazy until we know what they are and have something to compare them to agreed?
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