2003 Dodge Ram Hemi Engine Modification - 21st Century Hop-UP
A New Hemi Gets Old School Tricks
From the February, 2006 issue of Mopar Muscle
By Randy Bolig
Photography by Marty Fletcher
Since the beginning of time, as it pertains to automobiles, people have been changing and modifying these mechanical wonders in the quest for more power, better handling, and simply making their car better than the next guy. But over the years, the mechanical wizardry has taken on advancements that at one time were the things of science fiction. Cars, quite literally, are more computer-controlled wonders than mechanical ones these days.
But has that made the hot rodder extinct? Not by a long shot. It seems that no matter what kind of advancement, be it mechanical or electrical, the aftermarket suppliers will come up with a way to improve upon the O.E.'s basic design. It used to be as simple as changing an intake and carb, slapping on a set of headers, or installing a set of numerically higher gears, and, presto, improved performance. Is it still that simple? When it comes to the 21st century Hemi, almost.
Sure, the engine is computer controlled. Sure, it's fuel injected. Sure, there are a lot of accessory items mounted all over the engine, but underneath it all, it's still an internal combustion powerplant. So, theoretically, a few bolt-on upgrades would be an improvement, right? Well, keep in mind, since the engine's functions are computer controlled, that computer has set parameters for the functions the engine does. So, if we add a cold-air intake system, theoretically, the calibrations will change in the computer in regards to the fuel mixture. Now, with this simple modification, the change will not violate the parameter, and the result is usually a slightly leaner condition, resulting in an increase of horsepower.
Let's get deeper into the modifications. What if we add a cold-air kit, headers, and perform a cam and head swap? these are some above-average modifications, especially to an engine as new as the 5.7 Hemi. the computer will realize the increase in cylinder pressure (depending on the new cam specs, and the head's chamber volume), and the more efficient movement of the air and fuel mixture (resulting from the ported heads). This will require a special tuning be applied to the computer to compensate for the changes, correct? O.k., maybe we are thinking too deeply into the modification realm, and some of you just want to get a little more oomph out of your Hemi. Luckily, the modifications that have been going on for centuries still have merit today.
Comp Cams is now manufacturing...
Comp Cams is now manufacturing three different cams for the 5.7 Hemi. Their new XFI (Xtreme Fuel Injection) series of camshafts for Hemi-powered Chrysler vehicles, according to them, "dramatically increase engine horsepower and torque, yet retain compatibility with all OEM vehicle computer systems." The cams are available in three different profiles: XFI 260, 268, and 273. These three new camshafts are application-specific, with designs for street, street performance, and towing. We decided we would take a small step and choose the 260 version of these new cams. The XFI 260 cam features a .522/.525-inch valve lift, with 208/212-degrees of duration at .050-inch lift, and a 113-degree lobe separation. Since we were doing a cam swap, we thought it wise to also install a set of Comp's valvesprings to go along with their cam. Fortunately, these springs are the same as GM's LS-1, and readily available. Yes, it's a fairly small cam, but Comp tells us this particular cam needs no computer modifications. The large XFI 273 cam may require some computer reprogramming.
The Plan At first, we thought...
At first, we thought we could simply throw a bunch of parts at our '03 Hemi-powered Ram, and see what stuck. Well, common sense got the best of us, and we realized that wouldn't work. What we did do, however, was find out about some aftermarket manufacturers that are producing performance items for the new Hemi. But would we be able to tackle the work? We decided we needed to find a shop that was capable of working on newer computer-controlled vehicles and able to undertake the task we were throwing at them. Fortunately for us, we found KRC Performance in Cocoa, Florida. KRC Performance is the kind of place that will pick up your truck from anywhere in the continental U.S. and perform all the work. Whether it's a wild stroker motor or a show truck, KRC can handle it.
Normally, a torque converter...
Normally, a torque converter is swapped in favor of a performance piece that allows the engine to reach a higher rpm before engaging. The reason for this is usually for racing, where you need the engine to reach a certain rpm where more performance is available from the engine. In our case, we found that TCI has developed a truck torque converter they tell us increases power, efficiency, and fuel mileage. We also hear they are more durable than OE converters equipped with plastic stators. The new TCI converters for 5-45RFE transmissions feature an aluminum stator for increased torque multiplication and heavy-duty furnace-brazed components. they also tell us their converter delivers better power throughout the entire rpm range. So let's see, better performance and fuel economy, yep, that's what we need.
Gotta Getcha Some
So you want parts, and you want to know a little bit more about the ones we used. Well, here's your chance. All the parts are available with either a simple phone call or e-mail
Swapping heads on a musclecar's...
Swapping heads on a musclecar's small-block or big-block engine has been standard practice for many years. Smaller chamber, bigger ports-more power. But what's it take to do it to a 21st century powerplant? Remember, the engine's functions are controlled by a computer; change something that sends a function out of a given parameter, and the computer is lost. Patriot Performance in Rainbow City, Alabama, has a core-replacement program: you purchase a pair of their CNC-ported heads, they ship them to you, and you send your stock heads back to them. The Stage I heads we received featured the stock valves and springs, five-axis CNC porting, and a five-angle valve job. At .600-inch lift, the intake ports flow 300 cfm, and the exhaust flows 207 cfm at the same .600 inch.
Underdriven pulleys for engines...
Underdriven pulleys for engines are nothing new. Auto Specialties Performance (ASP) has developed one for our new Hemi. The pulley is 20-percent smaller than the factory unit, but the weight of the pulley is kept to the same spec. This alleviates any misfire codes with the computer, and, according to ASP, delivers 12 additional horses and an amazing 19 lb-ft. of torque. it requires a measly 30 minutes to install, and increases horsepower and torque. Sounds like a no-brainer to us. Just keep in mind, you will need to replace the factory belt with a shorter one.
Patriot Performance Head Shop
One of the most involved swaps you can do to your late-model Hemi revolves around the cylinder heads. But heads usually yield the largest improvement. keep in mind, an engine is a vacuum pump-the more air you move, the more power you make. The Patriot Performance heads are direct bolt-on performance heads that feature stock valves and springs, and a five-axis CNC porting.
|Lift ||2-inch in ||1.55-inch exh |
|.100 ||68 cfm ||51 cfm |
|.200 ||144 cfm ||116 cfm |
|.300 ||221 cfm ||161 cfm |
|.400 ||272 cfm ||185 cfm |
|.500 ||290 cfm ||197 cfm |
|.550 ||295 cfm ||200 cfm |
|.600 ||300 cfm ||207 cfm |
So it was time to begin. What we decided to do was install the Patriot heads, a Comp Cams camshaft, an ASP pulley, and a TCI torque converter. we figured it best to farm this much work out to someone capable of handling such a task, and Marty Fletcher at KRC Performance in Cocoa, Florida, was more than up to the task. But before we could begin, we needed to find out where our Ram was in regards to stock horsepower. So we strapped the Ram down on the dyno at White's Automotive, and let the chips fall where they may. When the wheel stopped spinning, our stock Ram possessed 249 hp and 263 lb-ft of torque. That's a pretty standard number in regards to a stock Hemi Ram, but we wanted more.
There you have it-we have a plan; we have parts; we have a baseline. The only thing left to do is tear into it. So follow along, and find out how easy it really is to contact the aftermarket and get the parts you need to increase your new Hemi's output. And the work isn't impossible to handle either.
With the level of modifications...
With the level of modifications we intend to do, pulling the engine seemed the easiest way to do it. KRC began by removing the radiator, A/C condenser (must be evacuated first), and the radiator support. We also removed the inner fenders to gain some clearance.
With all the accessories and...
With all the accessories and brackets out of the way, the engine was unbolted from the transmission, hoisted out of the truck, and attached to the stand.
With the engine on the stand,...
With the engine on the stand, the guys at KRC removed the stock components to be replaced. The front cover was removed, cleaned, and painted. the heads were removed, repackaged, and shipped back to Patriot Performance for the core replacement.
We wanted to pay homage to...
We wanted to pay homage to the legendary 426 Hemi, so Marty at KRC used Hemi Orange paint to cover the short-block.
On the new Hemi, the lifters...
On the new Hemi, the lifters are grouped in sets of four that are held in place with a locking bar. To remove and replace the lifters, simply unbolt and remove the bar, replace the lifters, and re-attach the bar to the engine block.
With the lifters out of the...
With the lifters out of the way, our new Comp XFI cam was slid into place, and the lifters and bars were re-installed.
Like the aftermarket MP timing-chain...
Like the aftermarket MP timing-chain tensioner for small-block LA engines, a tensioner was employed to keep timing in check.
Replacing the timing chain...
Replacing the timing chain on a 5.7 Hemi requires lining up three separate locations. The lower gear has its crankshaft-keyed groove in the two o'clock position; the chain has two blue links that go in at the six o'clock position; the top gear has a small dot that aligns with another dot on the chain at the twelve o'clock position.
Since we were using a slightly...
Since we were using a slightly larger than stock camshaft, we also changed out the stock springs on the Patriot heads. The O.E. springs on the heads may be fine for the small cam, but we wanted the added insurance of the aftermarket spring matched to the camshaft.
The Patriot heads began as...
The Patriot heads began as a stock cylinder head, and then received a five-axis CNC porting. This definitely increases the efficiency of the head-and power.
If you want to reduce parasitic...
If you want to reduce parasitic power loss, an underdrive pulley is the easiest way to do that. This ASP pulley is 20-percent smaller than the stock unit, and ASP tells us it's good for about a 12hp increase at the flywheel.
The engine definitely looked...
The engine definitely looked different thanks to a few cans of paint and some powdercoating on the oil pan and brackets. Then it was time to put it back in, but before we did, we decided to change the torque converter. The TCI converter has a slightly higher stall speed and is more efficient than the stock converter, so we couldn't help but install one. Remember to oil the converter's pump drive before installing it to avoid damaging the seal
It almost seems a shame to...
It almost seems a shame to cover up the engine with all the accessories.
What good is a performance...
What good is a performance engine if it can't breathe properly? We contacted Afco products, the makers of Dynatech headers, and got their SuperMAXX Hemi truck headers. The system is made of stainless steel so it will not rust, has an extra thick .375-inch flange so it shouldn't leak, and is fully OBD-II compatible. NOTE: Check your local laws, because according to Dynatech, "These products are intended for racing and off-road applications. Not legal for sale or use in the state of California, nor in states which have adopted California emission standards."
The Dynatech headers come...
The Dynatech headers come in a raw finish. We sent ours out for a ceramic coating to dress them up a little; ceramic coating actually helps performance.
The Dynatech headers are as...
The Dynatech headers are as easy to install as any header. Having the inner fender out of the way didn't hurt either.
The Dynatech header system...
The Dynatech header system came with everything needed to connect it to the factory system just in front of the muffler. Remember, you will need to cut the factory exhaust before the muffler in order to install the SuperMAXX kit.
From underneath, you can see...
From underneath, you can see the Dynatech system fits nicely under the truck and connects easily to the stock system.
It's a good thing that Gary...
It's a good thing that Gary White at White's Automotive is a patient man. When we got the truck running again, we were back at his place wreaking havoc one more time. This time, all our work rewarded us with final numbers of 318 hp and 333 lb-ft of torque at the wheels. That's an improvement of 69 hp and 70 lb-ft of torque. With a little tuning to the computer, the numbers will be higher. Before the parts melee began, we took the Ram to the track, but were disappointed with a 10.16 in the eighth-mile. When the new version hit the track, we were rewarded with a 9.70 e.t. We ran out of time, but are planning to get a proper computer tune-up and hit it again. Stay tuned.
Bumpin' On When it comes...
When it comes to camshafts, Comp Cams is one of the most recognizable manufacturers in the industry. Not wanting to miss the Hemi craze, Comp Cams came out with their new XFI grind camshafts for Ma Mopar's 5.7 Hemi engine. Three versions of the XFI cams are available depending on your need. According to Comp, XFI (Xtreme Fuel Injection) camshafts for Hemi-powered Chrysler vehicles dramatically increase engine horsepower and torque, yet retain compatibility with all OEM computer systems. The camshafts are application-specific, with designs for street, performance, and towing.
Auto Specialties Performance...
Auto Specialties Performance
Pulley for You
Underdrive pulleys have been on the market for quite some time, but for you Hemi guys, ASP has introduced a much-asked-for addition. The new pulley from ASP features a 20-percent reduction in size, while maintaining the factory weight to avoid throwing the computer into a tizzy. Keep in mind, this application will require a shorter fan belt (Gates PN K060988). ASP Racing claims this upgrade produces an increase of 19 lb-ft of torque and 7 hp to the wheels.
Dynatech Headers - A division...
Dynatech Headers - A division of Afco
Ask any hot-rodder what modifications they have made to their vehicle, and you can bet that headers will be one of the mods. A good flowing set of heads won't do you much good if the exhaust is all jammed up, but Dynatech can solve that problem. Their all-stainless-steel SuperMAXX kits feature a 1-3/4-inch long-tube design, with heavy-duty collectors and OBD-II compliant cats. Best of all, the SuperMAXX kits are a direct bolt-in and connect to the factory exhaust in front of the muffler.
KRC Performance If the mods...
If the mods we have shown here still don't offer you enough added get-up-and-go for your Ram, check this out. KRC Performance has come up with a turbo kit that will more than get your tires fryin'. You can either buy the kit from them and have them install it, or they can ship it to you for self-installation. Now that's the ultimate bolt-on.
TCI Automotive Converting...
TCI is making quite a name for itself these days with great performing torque converters they tell us increase power, efficiency, and fuel mileage. They also tell us they are more durable than OE converters that come equipped with plastic stators. TCI's Hemi truck torque converters are manufactured for 5-45RFE transmissions, feature an aluminum stator for increased torque multiplication, and heavy-duty furnace-brazed components. With a higher-than-stock stall speed rating and stronger thrust bearings, this torque converter is built to last.