I'm writing this post in hopes that it might be useful to some forum members looking to modify their 5.2/5.9 engines to get more performance out of their trucks. I've done a considerable amount of research on this topic, and feel reasonably confident in the following statements. What I really want is for people to have their eyes wide open BEFORE they start dropping money on parts and end up down the rabbit hole of costs. There is an unbelievably wide chasm between the quality of information available to the average gearhead online and the information put out by people in the know. Not to mention, the placebo effect is STRONG in the car world. Plenty of people spend hundreds of dollars on useless crap like throttle body spacers that claim to add 50hp and then they repeat that claim and say they can feel a difference when in reality nothing changed. People are not inherently scientifically minded, you must take testimonials with a huge grain of salt.


So I've been talking about building up my motor since I joined this board a couple of years ago. Despite doing an extensive amount of work to the truck(because it breaks constantly), I have yet to do much of anything performance based. One reason for this is that every time I start thinking about doing a build, I just get overwhelmed by the lack of quality information about these motors (in an EFI truck application), and the seemingly endless expenses and barriers to making even modest horsepower.

For example, let's say you want to build a 360 to make in the neighborhood of 300 horsepower(wheel), while still maintaining good bottom end torque and part throttle operation (since this is a big heavy truck you're dealing with after all). That seems pretty reasonable for a 360 cubic inch powerplant right? Well just to reach even that modest goal, there are considerable issues and extensive costs not known to the average guy.

First, the intake manifold will only flow ~180cfm, which strictly speaking MIGHT support 300 horsepower(https://www.hotrod.com/articles/airf...ylinder-power/), but if you look at the dyno charts, the torque curve falls off like crazy from 3500-5000 rpm. It is literally almost a 45 degree angle downward on the charts. https://www.google.com/url?sa=i&sour...65479212371809

The main reason you want more horsepower in a truck this size is for passing, which means you'll be running up in the 3500-5000 rpm range...where a stock 360 is producing about 175 ft-lbs Discussions about intake manifolds tend to fall into 1 of 2 categories. First is the group of people who think you should remove the keg and install a single plane manifold(M1) or something similar because they make so much more power. Trouble is, they don't actually make more power without better flowing heads, a big cam, and lots of RPM and they lose a ton down low, plus the throttle response is awful because intake air velocity is diminished considerable. Second is the group of people who say something along the lines of "look at your tach, you spend 99% of your time under 3000 rpm, so the keg is fine" which is true...but you also spend 99% of your time at part throttle so what are we even talking about. Passing is not generally a part-throttle endeavor.

To rectify this deficiency, the cheapest option(and really the only one available) is a $650 (plus shipping) Hughes airgap...which isn't even very good. The dyno results are mixed at best, and even the ones Hughes publish aren't exactly impressive.(see above) Some people claim not to lose bottom end, others claim they lost a lot of bottom end. Some people say they picked up some power, others state they didn't. It's really a crapshoot without unbiased dyno results. The consensus really is that the intake alone, despite the stocker being a restriction, is not enough to bump power up because now the restriction is the cam or heads. There are guys who report putting in a stroker crank (to make the engine a 408ci) and not gaining any horsepower at all because they didn't deal with the the inlet restrictions. They make a lot more torque down low, but torque down low isn't the issue here. The stock 360 has plenty of torque down low.

Second, the camshaft is teeny weeny. So to rectify this, you have to get a higher lift, longer duration cam. Fine, but then you need springs, then the pushrods might need changed, and then you need tuning (to be discussed later). Camshaft selection is a tricky business. The racer in all of us likes lots of lift, lots of duration, and a lopey idle. Unfortunately, in a street driven truck, these are not ideal. Narrow lobe separation angles hurt torque and rob engine vacuum. High lift can't be taken advantage of because the stock head is saturated by about .450" lift, so more is useless and possibly counterproductive. More duration can help, but only so much.

Third, the heads. So you've spent a couple thousand dollars at this point on an intake, a cam, supporting valvetrain...but you've still got heads that only flow about 230cfm (assuming you have enough cam lift to take advantage of this). 230cfm is actually sufficient to make 300+hp, but the heads have a tendency to crack between the valve seats. Knowing that, it's hard to justify building a nice motor and using the stock heads...because they are failure prone. So you pick up the cheapest replacement heads from EQ for $640...plus several hundred for valves, guides, seals, shop labor, etc. Now you're well over $2000 into this motor and it still has stock replacement heads, and a mediocre induction system...plus it may not even run at all because you still haven't addressed tuning.

Fourth, ECM tuning. By fat the biggest pain in the *** is the EFI. You could make a case that small block mopars are good economical engines, and in a carbureted application I might agree, but when you have to shell out hundreds and hundreds more for tuning, that may never even be right, just to get it to run with modifications, it's painful. So after you've spent several thousand dollars in aftermarket parts for your nearly stock magnum engine, you need to call Hemifever. Why hemifever? because he's the only person with a reputation worth a damn tuning these trucks. In all likelihood, he's not local to you which means you will have to do remote tuning. So pony up $600 for an SCT tuner and the custom tuning, plus $300 for a wideband o2 sensor and gauge to monitor your a/f ratios. From here, what I've read is that you're likely to spend a very long time fighting and fiddling with the tuning and having to go back and forth with hemifever many times to get this right. From my personal experience having custom tuning done on a cammed ls1 camaro I can tell you this is a ROYAL pain in the ***. The computer will inexplicable change things sometimes as it tries to re-learn and screw up an otherwise fine tune, or there will be some other nonsensical issue that arises and you'll chase your tail over and over replacing sensors and dicking with all of it. Add to this the fact that "fuel sync" is another issue that needs to be addressed. Fuel sync is some esoteric thing that people don't seem to know much about, but it requires a high end scan tool (like a multi thousand dollar snap on) to set/adjust. Have fun with that.

Fifth, last but not least, the transmission. You're not building an even remotely performance based engine and putting it in front of the stock transmission without expecting destruction. So get ready to either pony up $3000 for a mega-viper kit (plus rebuilder labor), or keep swapping in junkyard transmissions left and right. Not to mention, even when built to withstand the power, these transmissions suck royally at deciding when to shift and when to hold gears. They upshift at the wrong times, they downshift at the wrong times, they're just all around a crummy transmission compared to the newer 5, 6, and 8 speeds.

So all of this is to say that it really is not simple, nor is it inexpensive to make even modest power with these motors unless you want to switch to a carburetor...and who wants to deal with that on their pickup truck really? What's more, by the time you look at the costs above, then add in the costs of the machine shop work for the motor rebuild (you shouldn't be putting all these parts in 150,000 mile engines without also rebuilding the bottom end) you're literally spending more than (maybe double) the cost of a used ram with a 340-390 horse hemi...and you haven't touched the transmission yet. This is a lot of money to sink into a truck that is at best 19 years old at this point. I'm not saying you shouldn't do it, I'm saying you should think about it before starting down the path.


I love these trucks as much as anyone, and it really pains me to say all this, but as much as I'd like to build a better motor and make some more power with my 360...I just don't think it's worth it.

 

Yep. That's pretty much it. These engines were designed for trucks, so, gobs of power and high rpm screamin' just ain't gonna happen. Sure, you could build one to do that, but, then your truck would be worthless as a truck.... There ARE somethings you can do though......

Harland Sharp 1.7 ratio roller rockers. Good for 10 hp/tq on an otherwise stock engine.

Headers of some description. Even shorties are better than the stock manifolds... long tubes are out there, but, so far as I am concerned, the 1 3/4 inch primaries are too big for what you want to do. 1 5/8ths would be better to help build low-end power. But, headers with the smaller primaries are rare, and hideously expensive.....

Tuner. Just regular stock, canned tunes. Not much power increase, but, 15-20 lbs/ft torque..... more on the 98 and newer trucks, simply by eliminating/reducing torque management. (Dodges response to a weak trans....... dials back timing at low speeds, so, less power....)

On the 97 and older trucks, the y-pipe is also a big restriction in the exhaust. Right where the pipes merge into the cat, they crimp down significantly smaller than their already small 2" pipes..... So, an 'off road' y-pipe gives a bit of a bump as well. In combination with some good shorty headers, its a noticeable difference.

The biggest thing to remember is: The engine is a pump. It sucks air in, and then blows it out. If you want better performance, only doing stuff on one side of the equation is going to be disappointing, you have to address both intake AND exhaust sides, to fully reap the benefits of your mods. This is one of those things where the sum is more than just the individual parts. A well balanced engine will net you better performance, than one that has only been lopsidely tweaked.

Another option is to pick up a crate motor. Likely you can get the performance boost, for less money than you would spend building it yourself. And if there aren't any machine shops nearby you, (as in my case.....) it's a LOT more convenient.

And as always, if you REALLY want to make power, forced induction. Nothing wakes up a motor like a properly designed turbo or super charger setup.

Is it worth it? Skeptic makes a good point. For the money you invest, you could likely buy a newer truck, and instantly have more power than you would have gotten out of your magnum engine...... The money you invest you will also never recoup if you decide to sell it later.... So, it's a choice you gotta look at. If you plan on keeping the truck till the wheels fall off, then sure, spend as much as you like. If you think you are going to replace it in a year or three, then no, definitely not worth it.

 

See above comments in red.

Also, while I'm thinking about it, Heyyou, what has been your experience with guys running mild camshafts without a tune? Something like a 212/218 .410/.410 114lsa? I haven't seen any dyno sheets or drive reports on this, but thought maybe you had.

 

Originally Posted by HeyYou
Yep. That's pretty much it. These engines were designed for trucks, so, gobs of power and high rpm screamin' just ain't gonna happen. Sure, you could build one to do that, but, then your truck would be worthless as a truck.... There ARE somethings you can do though......

The point is, even if you don't want a high rpm screamer, but even a very modest engine that puts out even reasonable power inside the stock rev range (under 5k), it's an immense undertaking.



Immense? Not really. More complicated than carb? Yep. The price we pay for a 'more efficient'..... engine.

Harland Sharp 1.7 ratio roller rockers. Good for 10 hp/tq on an otherwise stock engine.

$400 for 10 horsepower...you can't even feel 10 horsepower



Nope. But, do it in combination with other mods, and you get more out of each of them, and no tuning is required.

Headers of some description. Even shorties are better than the stock manifolds... long tubes are out there, but, so far as I am concerned, the 1 3/4 inch primaries are too big for what you want to do. 1 5/8ths would be better to help build low-end power. But, headers with the smaller primaries are rare, and hideously expensive.....

Again, no evidence that this is a modification that will net much of anything on an otherwise stock motor. Plus, headers almost always leak. You can't hardly keep gaskets in them, and if you get cheap ones they allow valve noise to be heard which sounds terrible. I put shorties on my ram after doing a headgasket repair and felt 0 difference between them and manifolds......other than the super annoying ticking noise. Went back to manifolds 2 months later.



Remflex dead soft aluminum, or copper header gaskets. Torque 'em once, yer done. They don't leak. Ever. Done dozens, never had a comeback. And no, once again, in and of themselves, headers won't really do anything noticeable, however, in combination with other mods...... you get more out of both. (notice a trend here??)

Tuner. Just regular stock, canned tunes. Not much power increase, but, 15-20 lbs/ft torque..... more on the 98 and newer trucks, simply by eliminating/reducing torque management. (Dodges response to a weak trans....... dials back timing at low speeds, so, less power....)

Forgot to touch on this, but I actually bought a superchips tuner thinking it would make a difference since I have an 01 which is (according to the forums) loaded with torque management and the "death flash". Superchips claims something like 50 ft-lbs. They're full of ****. It MIGHT be good for 20 at best and I'm the optimal target. Not to mention, the tuner jacked up my shift points causing the truck to shift from first to second then back to first before going into third, caused the truck to ping like crazy (even with 91 in the tank and 87 tune loaded and a fixed plenum). I contacted them several times and their final response was to blame my spectre cold air intake for the problems, which is clearly wasn't causing.



A lot depends on who you get your tuner from, and even then, results are a real mixed bag. Fair few folks have used hemifever tunes/tuners, and posted good results. (there is even a dyno test in the general discussion section.)

On the 97 and older trucks, the y-pipe is also a big restriction in the exhaust. Right where the pipes merge into the cat, they crimp down significantly smaller than their already small 2" pipes..... So, an 'off road' y-pipe gives a bit of a bump as well. In combination with some good shorty headers, its a noticeable difference.

The biggest thing to remember is: The engine is a pump. It sucks air in, and then blows it out. If you want better performance, only doing stuff on one side of the equation is going to be disappointing, you have to address both intake AND exhaust sides, to fully reap the benefits of your mods. This is one of those things where the sum is more than just the individual parts. A well balanced engine will net you better performance, than one that has only been lopsidely tweaked.

Another option is to pick up a crate motor. Likely you can get the performance boost, for less money than you would spend building it yourself. And if there aren't any machine shops nearby you, (as in my case.....) it's a LOT more convenient.

Even if you spend several grand on a crate, you're only going to find them in carb format. You've gotta deal with custom tuning and the expense of at nearly $1000 for the tuner, tunes, and wideband.



I think Hemifever's custom tunes run 5-600 bucks, and another member got a wideband O2 sensor for around 200. Worked great for him. Yes, it ain't cheap, but, that is going to be the case on ANY computer controlled engine, and the newer ones are getting to be even more fun.

And as always, if you REALLY want to make power, forced induction. Nothing wakes up a motor like a properly designed turbo or super charger setup.

The magnums have a problem with pinging already, I can't imagine throwing even a small blower making like 6psi on this thing without doing something to address the detonation. Sounds like a recipe for disaster...probably why there were so few companies who offered supercharger kits for these engines compared to the GM/Ford/Hemis.



Please note that I SPECIFIED "Properly designed"..... Yeah, if you just slap some boost on it, you are going to blow it up. Just like any other motor. And yes, forced induction isn't cheap by any stretch of the imagination.

Is it worth it? Skeptic makes a good point. For the money you invest, you could likely buy a newer truck, and instantly have more power than you would have gotten out of your magnum engine...... The money you invest you will also never recoup if you decide to sell it later.... So, it's a choice you gotta look at. If you plan on keeping the truck till the wheels fall off, then sure, spend as much as you like. If you think you are going to replace it in a year or three, then no, definitely not worth it.

 

I think we basically agree on everything, you're saying that the proper combo makes decent power, and I'm saying a proper combo is more expensive than people think.

I will say though that I ran Remflex gaskets on the short headers and they leaked immediately. Torqued to spec and secured with stage 8 locking bolts. That being said, the headers were cheap chinesium, so the flange was probably warped and to blame, not the gaskets.

I edited in a cam question above, not sure if you saw it.

 

I don't think there is anything 'cheap' about working on fuel injected motors. Yep, we agree.

There are some cams out there that advertise not needing computer tuning to run properly. They ARE better than stock, but, once again, you run into the cost/benefit thing...... I think the CHEAPEST cam I have seen for these engines is still north of 300 bucks, some as high as 600..... I would imagine similar gains to the HS rockers.... but, a LOT more effort required...... I haven't seen any (what I would consider) reliable dyno tests on them though.

Another thing to consider would be simply buying the software/hardware to do your own custom tunes.... HP tuners (a sponsor here on Dodge Forum) offers a couple packages, for not much more than what you would spend on someones canned tunes......

 

The way things are going, I've very seriously considered buying tuning software and trying to teach myself how to tune...unfortunately 2nd gen rams are not supported by HP Tuners, and HP Tuners would be the one to buy for the vehicles I plan to buy and modify in the future.

 

At one time, I thought they did????

They aren't the only game in town though.

 

It's not listed on their supported vehicle list: https://www.hptuners.com/vehicles/ and from the forum posts I've read it seems they were saying they were working on it for like 10 years and then just failed to do it. The vehicles were old enough at that time and popularity was low compared with more modern powerplants that they probably didn't want to invest any more time in it.

What else really is there? SCT is wicked expensive because you've gotta buy the handhelds for each one you tune plus the software and they have yearly repeating costs.

 

BGTuners. They even support the 2nd gen trucks. For 500 bucks, you get everything you need to create your own tunes. That's for ONE vehicle though...... But, I only have one..... and for LESS than the cost of someone elses custom tunes, I can do my own.