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clint
Dodge Dakota
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9/23/2006
22:31:23
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 Subject: power question
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i was wondering today why exactly to i loose power at about 5500 rpm? what can i do to keep the power goin? or atleast keep it from droping. im not looking to get 7k out of it but if i had a solid 6k with all the power it would be nice. cuz when im sliding i get right at the comfort zone but its really short and then the power drops. so i could use the extra revs.
i was told if i hollow out the cat "and get an o2 sim" that i would get a good 500rpm out of it. true? or no. i was alost told to get some triple rate valve springs and i could wind it out to 6500 no problem. but why do that if i dont have the power up there?
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What
Dodge Dakota
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9/23/2006
23:20:09
| RE: power question
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What engine?
That kind of information is important.
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LimboDak
Dodge Dakota
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9/23/2006
23:35:26
| RE: power question
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Kowalski
GenIII
9/24/2006
08:19:21
| RE: power question
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Valve springs will stop the valves from "floating" at higher rpms (when the spring can't close the valve as fast as the engine is spinning, so it "floats" rather than following the cam); but its really the profile of the cam that gives the engine much of its power curve. You want what we commonly call a "bigger" cam, this will move the power band where you want it (also likely increasing peak power) but usually at a cost of low end power. It should be matched to the rest of your mods - bigger cams commonly work better with mods that help more air move through the motor,lower gearing, and looser torque converters.
Lead, follow, or get out of the way
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.boB
Dodge Dakota
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9/24/2006
11:35:19
| RE: power question
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Hollow out the cat: Maybe. You might get a little extra flow out of the exhaust. PArticularly if it's old and not working as well as it should. A better option would be a high flow cat.
O2 Simulaters: Bad idea. You don't want to lose the closed loop function during normal driving. And it will not gain you any power.
Triple valve spring: The worst idea yet. Triple springs have a very high seat and open pressure. So high that you can't get that spring pressure with just one spring. I'ts not really three springs, but two strong ones and a damper. The increased pressure puts a lot of strain on the stock valve train, and increases rotational stresses on the cam. Unless you're planning on replacing the entire valve train with matching parts, the valve train won't last.
If your springs are worn out and allowing float at a lower rpm, replacing them with Comp Cams beehive springs would be a darn good idea.
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clint
Dodge Dakota
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9/24/2006
23:00:57
| RE: power question
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99 318 with 97k on it.
r/t cam, mopar pcm, intake "manifold", 52mm tb, headman headers, 3 inch all the way back.
i know an o2 sim wont give me more horse. but if i pull the cat or hollow it out i will need it since its placed behing the cat.
sooo then what if i just get stiffer springs? do you think the valves would be floating at only 97k?
and instead of treating me like a dumb $hit why dont you give me some answers on how i could get higher rpms?
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Kowalski
GenIII
9/25/2006
14:59:55
|  RE: power question
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Excuse me ? I already gave you the best answer on how you could get higher revs !
If you feel as though I treated you as a dumb $hit,and you learned nothing new - then you didn't need to ask the question...
Lead, follow, or get out of the way
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Mopar318
GenII
9/25/2006
15:25:43
|  RE: power question
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Clint..to get higher RPM's you must install a high speed performance cam anylizer. This allows your cam to be adjusted correctly with the throw out tube. You can also install dual over head valve springs. Hope this helps.
Stupid Remarks recieve stupid answers.
Old setup: 1/4 mile on old setup: 13.965 @ 100.10 MPH, Crappy 2.236 60' on street tires
Mods: Paxton NOVI 2000 supercharger @ 10 #'s, M1 4Bbl, F&B 58mm TB, Gibson headers, JBA Y-pipe, and a Locker
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clint
Dodge Dakota
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9/25/2006
19:23:07
| RE: power question
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all you said is if the springs are worn out that i should get some comp cam beehive springs.
do you think the springs would be worn out at 97k?
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Mopar318
GenII
9/25/2006
21:16:15
| RE: power question
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To answer the question..No your valve spring shouldnt be worn out at 97k. Your not gonna be making power past 5500 with that combo anyways so there is no sense in winding past that.
Old setup: 1/4 mile on old setup: 13.965 @ 100.10 MPH, Crappy 2.236 60' on street tires
Mods: Paxton NOVI 2000 supercharger @ 10 #'s, M1 4Bbl, F&B 58mm TB, Gibson headers, JBA Y-pipe, and a Locker
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.boB
Dodge Dakota
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9/25/2006
23:00:42
| RE: power question
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I said you should consider the beehive springs. Could your stock springs be worn out at 97K? Maybe. If you're going to replace them with anything, use the beehives and avoid "triple" springs like the plague.
What exactly are your cam specs?
If your goal is to make power >5500, and not just rev above that, it's going to get expensive. One of the big limiting facters is the heads. They are a truck head, designed to make low end torque and meet emissions regs. They do a pretty good job of that. They do not do a good job at making high rpm power.
But be carefull, because this is a very slippery slope. If you swap the heads to a set of Edelbrock alum, they will increase air flow and compression. But now you need new rocker arms and push rods. And you'll need to upgrade the fuel system for the new air flow. That will also require a custom map. The more you do, the more you have to do.
Here's what I would do. Install a blower. Yes, it's expensive. But not as much as you think. You're at the point where you've done all the simple mods to make power. You either have to go forced induction, nitrous, or major engine work (like new heads).
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clint
Dodge Dakota
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9/25/2006
23:31:46
| RE: power question
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damn. thats were im stuck. i dont know which way i want to go. forced induction or all motor. a blower is simpler but.... idk. ok thanks for the info helped out alot. i think nitrous is the nest upgrade. prolly like a 75 shot just to keep it clean. cuz i know ill be using it alot lol
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Kowalski
GenIII
9/26/2006
15:04:20
| RE: power question
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Contrary to what boB says, there is nothing in your post to indicate you have done what is needed to make good normally aspirated power. As I tried to clue you in before, it is the stock cam that limits the higher rpm power of the 5.2. There is more power availabe for this motor from a cam swap at higher rpms before you run into limitations from the heads.
Lead, follow, or get out of the way
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daddio
Dodge Dakota
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9/26/2006
15:23:43
| RE: power question
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clint, "a blower is simpler but...."
how so?
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OBIO3
Dodge Dakota
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9/26/2006
15:50:26
| RE: power question
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First off. I do not abuse my truck just so you know why I'm going to say what I say here.
Without going to the shop, Is the redline not close to this 5500 RPM? And is the rev limiter not set close to this redline? Makes sense to me. question is, are the valve springs actualy floating or is the rev limiter kicking in. It sounds as though all these revs are really important to you. I don't think you need to worry about it to terribly long. unless you build an engine (pricy) to handle these higher revs your looking for, The one you have now will be toast. Just my opinion.
So many problems ....So little time
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clint
Dodge Dakota
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9/26/2006
20:54:30
| RE: power question
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i think you guys should go read my second post again. i already have an mopar performance r/t cam. and a mopar PCM. the stock 5.2 redlines at 5200. now with the pcm it redlines at 6. the stock 5.2 loses power at around 4800 if you look at limbodaks post. now i dont loose power till about 5500. so there is another 500 rpm in there that i would like to have had. but bob made it clear that there isnt a cheap clean easy way to get the revs.
blower is easier cuz you dont have to pull apart the whole motor to do it and it all comes in a kit. my opinion but i havnt delt with a blower b4 so maybe im wrong ... SOOORRRY
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Mopar318
GenII
9/26/2006
21:09:45
| RE: power question
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I would like to see a dyno sheet that indicates a R/T cam makes power till 5500. That cams a joke sorry to say. Good for a few hp...the only reason I could using that cam would be if your in california where emmisions are strict and you dont wanna mess with different length pushrods, valve springs, etc....
That dyno chart is for a 4.7. My truck dynoed its peak power at 4250 rpm. With the R/T cam the powerband may have been slightly higher but nothing close to 5500.
Old setup: 1/4 mile on old setup: 13.965 @ 100.10 MPH, Crappy 2.236 60' on street tires
Mods: Paxton NOVI 2000 supercharger @ 10 #'s, M1 4Bbl, F&B 58mm TB, Gibson headers, JBA Y-pipe, and a Locker
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clint
Dodge Dakota
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9/26/2006
21:57:35
| RE: power question
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its a seat of the pants feel. it might not be the max hp but it still has the power. it drasitcly drops at 5500. it pulls and as soon at you get to about 5500 it lets off. what was done to your truck? i know my max is higher than that. id say somwere around 45-47 is my max. if i manualy shift it at 5500 it drops to 4500 "from second to third" and its the perfect shift. you can feel it pull from 60 all the way till it gets to about 5200 and it will shift into 4th.
the r/t cam is emission exempt in all states. and is "not for highway use" but it dose only have 458/467 of lift. do you think if i got 1.7rr would it lift it too much? i was told you dont want to go anything higher than 520 on the magnum motors. wold i pass that? would that increase top end at all?
im not looking for a higher max hp. im just lookin to keep the power from dropping at 5500. bob has kinda answered that but everyone seems to think different but they wont say what i could do. thats all i wanted to know in the first place.
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Mopar318
GenII
9/26/2006
22:16:35
| RE: power question
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Part of the problem is I still dont understand what you are trying to ask. Is there a problem with the setup? I have no doubt that it pulls all the way to 5500, but when your shifting into the next gear your above your powerband.
Now you have asked to different question. You asked how to get more revs...but you also said you loose power at 5500 so why would you want to rev it out anymore? The reason your losing power after the 5.5k mark is because your not setup to be making the power past that mark. This would require some good flowing heads and a larger cam. I have never seen a magnum benifit from reving out that much unless they have a heads/cam combo with 10;1 compresion or higher. Boosted application such as myself also benifit from "reving out"
Old setup: 1/4 mile on old setup: 13.965 @ 100.10 MPH, Crappy 2.236 60' on street tires
Mods: Paxton NOVI 2000 supercharger @ 10 #'s, M1 4Bbl, F&B 58mm TB, Gibson headers, JBA Y-pipe, and a Locker
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clint
Dodge Dakota
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9/26/2006
22:23:26
| RE: power question
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ok i just went out a lil bit ago and pulled some holeshots in my truck. first time i actually "practiced" holeshots in it. and heres how it went.
spins through first "but feels like the fastest take off
shifts to second and is at about 3500 cuz it catchs traction and lowers the rpm.
3500-4000 nice smooth pull
4000-4500 pulls hard and keeps pullin
4500-5000 still pulling but flatlines at aroun 46-4700
5000-5500 is just flat. dosent drop but dosent pull neither. it might drop at about 53-5400.
after 5500 theres nothin it just drops and yu can feel the truck slow down till you hit the limiter.
thats my "worded dyno chart." i bought the truck with everything dont to it from a dealer who didnt know exactly what it had. so im not sure what kind of intake or any internals it might have. they didnt even know if it had a lower gear ornot. so from that and the list of parts i said i know it has done to it what do you think could keep the hp from dropping at 5500?
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clint
Dodge Dakota
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9/26/2006
22:26:15
| RE: power question
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p.s. any tips on the holeshot would be greatly appreciated "its an auto"
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