THE RELENTLESS PURSUIT OF POWER

A DECADE OF FORWARD PROGRESS FOR THE 7.3L POWER STROKE

Good engines never die, they just age well. Nearly 15 years since the last one left the assembly line, the aftermarket continues to push the 7.3L Power Stroke to new heights. While the HEUI-injected, 444ci V8 was once thought to be an engine platform to run away from, a paperweight even, over the past decade it’s become a viable performance alternative to expensive commonrail Duramax and Cummins mills. Turbos, tuning, injectors, head work, cams, and even low-pressure oil delivery have all been vastly improved. Even though most have moved on to bigger and better things, the 7.3L die-hards remain—and they’re consistently pushing the envelope further and further.

DW-1705-TREE-01 — Tony Salokas’ ’01 F-350 incorporates all the technological advancements that have come to light in the 7.3L segment over the last half decade. His truck knocks on the door of 800 rwhp with a streetfriendly set of injectors, cam, ported heads, and a single turbo. You’ll find more information about his parts combination in the following pages.

DW-1705-TREE-02 — To get past one of many horsepower barriers, 7.3L enthusiasts needed more than dropin turbo options if the bar was going be raised. Although a few companies had built or offered T4 turbo mounting options prior to Irate Diesel Performance, arguably no one else could match the quality, completeness, and affordability the Irate kits offer. Being able to run the same high-flowing BorgWarner and Garrett T4 turbochargers as the Duramax and Cummins guys was a game changer for 7.3L die-hards, and Irate’s kits make it all possible.

DW-1705-TREE-04 — Here you can see one of Irate’s T4 turbo mounting kits installed on an old-body-style Ford. The T4 kit allowed the owner to add a billet compressor wheeled S468 to match a set of 300/200 hybrid injectors, an SRP1.1 high-pressure oil pump, and healthy electronic fuel supply system. Conservative yet spot-on PCM tuning from Gearhead Automotive Performance culminates in a 200,000-mile truck that makes a 100% streetable 580 rwhp.

DW-1705-TREE-05 — The box S467.7 turbo (S400SX, PN 178855) from BorgWarner has become the weapon of choice in 7.3L builds ranging from 500 to 700 hp. Utilizing a forged milled wheel (FMW) compressor with the ability to move 85 pounds per minute (1,200+ cfm) and the proven 83mm turbine wheel, it provides great drivability for streetdriven trucks that still tow on a regular basis. And—believe it or not—this turbo resides on the highest horsepower (chassis dyno confirmed) 7.3L on the planet (skip to the last page of the article for more on this). While the numbers and positive feedback are still pouring in, it appears that BorgWarner’s new SX-E line of turbochargers will be even more impressive (the “E” meaning enhanced). SX-E units come standard with a high-flow, forged milled wheel compressor, aerodynamically optimized compressor housing, and 360-degree thrust bearing. Among the list of other BorgWarner turbos destined for greatness are the relatively new S472SX-E (with a 10-blade FMW wheel, 87mm turbine, and 360-degree thrust bearing) and S476SX-E (10-blade FMW wheel, 87mm or 96mm turbine, and 360-degree thrust bearing).

DW-1705-TREE-06 — Another cutting-edge turbo used often in the 7.3L segment is the GTX4294R: a 71mm ball bearing charger from Garrett that performs like a 75mm (or larger) unit without any tradeoffs in spool-up. The 75.8mm GTX4202R was a hit on bigger horsepower builds as well. As we went to press, Garrett had just released its second generation (Gen II) line of GTX turbos, which it claims will be good for 10% more horsepower over first-generation units.

DW-1705-TREE-07 — A true testament to how far tuning and turbo technology has come on the 7.3L can be found on Zach Green’s ‘01 F-250. His dually-converted puller (dubbed “Goin’ For Broke”) sports a stock forged-rod bottom end engine, a set of 300/400 injectors, Swamp’s Gen3 high-pressure oil pump, Power Hungry Performance tuning, and competes in the local 2.5 Class thanks to a cutting edge 2.5-inch inducer turbo built by Engineered Diesel. Despite having a 2.5-inch inducer turbo (63mm is miniscule when you’re talking about feeding 7.3 liters of displacement), Green regularly runs neck-and-neck with some of the strongest running trucks in the Southeast.

DW-1705-TREE-08 — On Beans Diesel Performance’s chassis dyno, Zach Green’s ’01 F-250 just cleared 582 hp at the wheels, albeit being about 10 psi down on the kind of boost he sees while pulling due to the dyno not being able to effectively load the truck. Trust us, squeezing this kind of power through a 63mm turbo on a 7.3L and then being able to keep pace with 850+hp Duramax and Cummins-powered GMs and Dodges is no small feat—and something we never thought we’d see just five years ago.

DW-1705-TREE-09 — While there isn’t a lot of public information available on the ported heads offered from companies like Swamp’s Diesel, Carson Stauffer, and Crutchfield Machine, they are worth the money. And even if they don’t add a huge increase in flow, more importantly they may offer better swirl than the factory heads. In conjunction with adding a Stage 2 cam from Gearhead Automotive Performance, Brian Jelich’s 1,000hp ’00 F-250 picked up 3 mph in the eighth-mile (roughly 100 hp) by adding a set of worked-over heads from Crutchfield Machine.

DW-1705-TREE-11 — As we stated in the opening of this article, Tony Salokas’ ’01 F-350 embodies all the advancements the 7.3L has seen in the last 5-7 years. His truck sports a Carson Stauffer-built engine with a billet S475 from Barder Turbo Service, a Gearhead Automotive Performance Stage 2 cam, Stage 2 ported heads from Carson Stauffer, tuning from Swamp’s Diesel along with Swamps’ 300/200 hybrid injectors and Gen3 high-pressure oil pump, and a 1375 fuel supply system from Marty’s Diesel Performance. This potent combination propels the truck through the eighth-mile in 7.43 seconds at a blazing 93 mph on fuel alone, which means 780 rwhp is on tap before Salokas even thinks about activating the single-stage Nitrous Express system.

DW-1705-TREE-10 — Although camshaft development wasn’t a frequently visited area in 7.3L performance for quite some time, Gearhead Automotive Performance dove headfirst into this segment roughly seven years ago. The company’s Stage 1 cam (shown) is a direct bolt-in replacement that provides improvements throughout the entire rpm range. Thanks to increased lift, duration and lobe ramp speeds, along with the cam’s intake valve opening area receiving a 15% increase and a 10% increase on the exhaust valve side, the end result is better low-rpm drivability (before the turbo spools), more horsepower up top in high-horsepower applications, and lower EGT. Gearhead’s Stage 2 cam requires fly-cut pistons and valve springs with no less than 150 ppi seat pressure, but complements cylinder heads with extensive port work (such as what you’ll find on the trucks that follow).

DW-1705-TREE-13 — With competition-ready custom tuning that calls for 3,850 psi worth of ICP (injection control pressure), Salokas keeps an eye on high-pressure oil pump pressure via this ISSPRO gauge mounted to his steering column. While 3,200 psi was once thought to be the accepted maximum, you certainly can’t doubt the kind of power the truck is making (780 rwhp on fuel) with this kind of ICP being commanded. A high-volume, low-pressure oil pump (LPOP) from DieselSite is good insurance for keeping up with this type of ICP demand (more on the DieselSite LPOP later on).

DW-1705-TREE-14 — One of the pioneers of big horsepower 7.3Ls is Brian Jelich from Currituck, North Carolina. Back when making 500 hp with a 7.3L was a big deal, he was laying down close to 700. Never afraid to push the limit, Jelich would lay claim to the highest horsepower 7.3L in the land at one point in time. This photo was taken six years ago, when (with the aid of a three-stage nitrous system) he cleared 1,069 rwhp. A set of Swamp’s Diesel 400/400 injectors and Gen3 high-pressure oil pump, S480 turbo, a built engine, and the aforementioned boatload of nitrous helped get him there.

DW-1705-TREE-17 — Sending roughly 1,050 hp to the wheels, Jelich’s Super Duty has laid down a best eighth-mile pass of 6.663 at 107 mph (which equates to 10.4 seconds at roughly 134 mph in the quarter-mile). Thanks to the improved airflow provided by the ported heads and cam, he is able to run the fastest he ever has and only has to use a 0.52 and 0.82 jet in his two-stage nitrous system to get there (versus needing three stages just five years ago). Adding the Crutchfield Machine heads and Gearhead Stage 2 cam to his setup also culminated in an 8psi drop in boost (i.e., the engine is making more power while not having to work as hard).

DW-1705-TREE-18 — Would you believe an 8,200-pound, 7.3L-powered dually was behind this tractionlimited, 7.30-second eighth-mile pass at 96 mph? Thanks to a big set of compounds (S475 in the valley and a 104mm S510 atmospheric), full engine build including extensively ported heads from Crutchfield Machine matched to a one-off camshaft from Comp Cams, and countless other parts, Scott Morris’ ’00 F-350 makes north of 950 rwhp on fuel alone! Nasty doesn’t even begin to describe it, and what’s more is that Morris drives the truck to work every day, in addition to towing, sled pulling, and drag racing with it.

DW-1705-TREE-15 — Shortly after that, Jelich sported this massive compound arrangement. The atmosphere charger was a 101mm unit from Precision Turbo & Engine (PT101), while an S475 was used as the highpressure turbo in the valley. While this setup yielded roughly 75 more hp over the single setup, Jelich would eventually go back to running a single charger for its simplicity.

DW-1705-TREE-19 — Custom tuning is the only way to make your parts combination work in perfect harmony, and it’s also the glue that holds high-horsepower 7.3Ls together. Just like turbo technology, the tuning market has improved tremendously over the past decade, and there is no better way to illustrate this point than to talk about out how far tuners can push a stock-bottom-end engine these days. Countless high-mile, forged-rod 7.3Ls are in the 550-to-600rwhp range, if not past it. In order to avoid an over-torque scenario on stock bottom end mills (when too much cylinder pressure can bend connecting rods), the industry’s best tuners know to limit timing advance until higher engine speeds. Instead of pouring on the fuel at 2,000 rpm, it comes in around 2,500 rpm or higher.

DW-1705-TREE-16 — In addition to going back to a single S475 (a high-end unit sourced through Rudy’s Diesel Performance), Jelich also went with a Stage 2 cam from Gearhead Automotive Performance and ported heads from Crutchfield Machine in 2015. The heads and cam combo brought him right back to the power level he was at with the compound turbo arrangement.

DW-1705-TREE-20 — While the TS Performance six-position chip and F5, F6, and Infinity from DP-Tuner are still popular tuning platforms, the Hydra Chip from Power Hungry Performance has all but reinvented the wheel. The Hydra offers 17 total positions available on the fly, and supports most custom tuner calibrations (meaning you can run your favorite files from different custom tuners on the same device). Units are Internet updateable so there’s no more pulling and then reinstalling the chip onto the PCM; a virtually endless (and free) array of calibrations are available through Power Hungry Performance, one of the premiere tuners in the industry.

DW-1705-TREE-21 — It goes without saying that 7.3L performance wouldn’t be where it is today without the advent of hybrid injectors. Due to the complex nature of the oil-fired HEUI injection system, the hybrid platform made it possible to make big horsepower without running out of high-pressure oil. Using the standard hybrid as an example, an A-code 7.3L injector is fitted with a 7.1mm diameter plunger and barrel assembly from an International I530E engine (BD-code injector) without any machine work being required (for reference, the stock plunger and barrel measures 6mm in diameter). This effectively increases the bore of the injector, making it flow approximately the same as a much larger BD-code injector (238cc). And by retaining the factory 16mm diameter intensifier piston, no additional high-pressure oil is required for the injector to operate.

DW-1705-TREE-22 — Not unlike any other diesel injector, larger nozzles are employed on both hybrid and conventional injectors in order to up their injection rate (i.e., inject more fuel volume in a shorter amount of time). While some enthusiasts swear by running nothing smaller than a 200% nozzle, others feel 30, 80, or even 100% nozzles have their place as well. In an all-out performance tune (with supporting airflow) the 80% nozzle on a 238cc hybrid (shown) can produce 500 to 525 rwhp and be virtually smoke-free on the street. The biggest names in the 7.3L injector game are Full Force Diesel, Swamp’s Diesel Performance, Unlimited Diesel Performance, and Rosewood Diesel Shop.

DW-1705-TREE-23 — This flow chart from Unlimited Diesel Performance illustrates the benefi ts of running a hybrid injector over a conventional modifi ed unit. In it, you can see that the company’s standard hybrid (the 238/80) fl ows its maximum of 238cc worth of fuel with 3.5 milliseconds of pulse width, and requires just 2,500 psi of injection control pressure (ICP), whereas a conventional injector would need 3,000 psi of ICP before maximum fl ow was achieved. Thanks to the 80% nozzle, a quicker injection rate exists; that is, more fuel can be delivered in a specific window of time (fuel per time). This means less pulse width can be commanded and less high-pressure oil used to achieve your horsepower goal. As more internal modifi cations are made to the larger versions of the hybrid injector and a larger nozzle is added, the benefi ts of running a hybrid unit become even more clear.

DW-1705-TREE-24 — Because dual high-pressure oil pump setups demand so much oil, bottom end lubrication can become scarce. DieselSite’s high-volume low-pressure oil pump was designed specifi cally for this purpose. The larger pump features custom cut, ground, and polished gears for improved effi ciency and less wear. When compared to the factory low-pressure oil pump, the DieseSite unit provides 30-60% more oil pressure (depending on whether you’re idling, steady-state driving, or free-revving).

DW-1705-TREE-25 — Need more proof that things have come a long way for the 7.3L? Check out Matt Maier’s ’97 F-250. His truck holds the highest 7.3L horsepower number ever made on a chassis dyno at 1,226 hp—and he did it with a stock forged-rod bottom end! The combination of 350/200 hybrid injectors, a BorgWarner box S467.7 turbo, dual high-pressure oil pumps, and (most importantly) spot-on custom tuning from Gearhead Automotive Performance allowed the engine to live through countless low 7-second eighth-mile passes prior to being hit with what was essentially a 600hp shot of NO2 to set this record.

While turbo technology appears to be the primary reason behind all of the 7.3L’s recent success, head work, improved camshafts, and tuning all played a role in getting these dinosaur V8s to where they’re at today. Thanks to all the new technology, horsepower continues to climb. Just five to six years ago, it took a set of 400/400 hybrids and an 80mm turbo to knock on the door of 700 rwhp—but now a set of 300/200s, the right head work, a good cam, and a 75mm charger can get you nearly 100 hp more than that. Not only will we elaborate on the parts that are reinventing the 7.3L performance wheel this month, but we’ll also profile a few of the hottest running trucks in the business.DW

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