Through the course of many years, Ford's 7.3L Power Stroke engine has earned itself a reputation for being a reliable workhorse. Even though the engine hasn't been produced in nearly 16 years, it still has a die-hard following in the diesel community. It is not unheard of for truck owners to sell their newer model to get a 7.3L-powered rig. Their popularity can be seen in the marketplace as well, with prices sometimes outpacing later-model Ford trucks.
The only real downfall to Ford's fabled 7.3L Power Stroke is the amount of power the engine makes—or lack of it. First, take into consideration that the engine was state of the art when it first came out, with respectable power numbers. Also, not being a powerhouse is one of the factors that makes the engine reliable. The problem is, people's perspective of how much power an engine should make is skewed. The high bar set by modern diesel-engine performance is one of the culprits; the other is aftermarket performance parts' ability to really boost power. But newer trucks have drawbacks: their price tags and some of the big upgrades that can be performed may cause reliability issues.
In our continuing series about transforming Jared Lehenbauer's new-to-him (somewhat neglected through the years) '01 Ford F-250 into a truck that suits his need for a reliable tow rig, we focus on making engine improvements. The years of hard use have started to take a toll on the 7.3L. Under heavy load, the turbocharger sometimes makes a squealing noise, the engine occasionally runs rough (injector cleaner helps smooth it out), and if the truck sits more than a day or two, it is difficult to start (HPOP is losing prime because of oil seeping past the injector O-rings into the fuel). So, the time has come to update some of the worn engine components and liven up the output for more efficient towing, without losing the dependability the truck is known for.
We made a call to KC Turbos to talk to the crew about a new drop-in turbocharger for the 7.3L that they had been working on: the KC300x. We discussed our setup and what we plan to do with the engine. The guys at KC assure us they have the right setup (turbo configuration, injectors, and ECM tunes) to use with the KC300x for waking the truck up, improving towing, and providing excellent driveability.
After making some quick repairs (replaced injector O-rings) to make sure the truck was reliable for the trip, we hopped in the Super Duty and drove east to Apache Junction, Arizona, to KC Turbos.
| Upon arriving at KC Turbos, the first order of business is putting the '01 Ford F-250 on the dyno to get baseline power and torque numbers (for later comparison). But, before the test, KC Turbos' James Bolen disconnects an old Banks Six-Gun unit to ensure the ECM has a true stock calibration for our baseline dyno run.
| The truck is backed onto the dyno and securely strapped down. We are cautious with the 37-inch tires, as they are not designed for speeds close to 100 mph. With Charlie Fish (KC Turbos' owner) at the controls, the truck is able to muster 226 hp and 474 lb-ft of torque in stock trim.
| Power Upgrade Modernizing A 7 3l Power Stroke 004
| After the baseline run, a Power Hungry Performance Hydra 7.3L Power Stroke Performance Programming Chip is installed. The Hydra is good for stock trucks because it provides 15 slots for custom ECM calibrations. It also gives users "No Start" and "Module Bypass" settings, along with change-on-the-fly capability. For the transmission, the Hydra adjusts the shift strategy for each tune (with the injector and turbo setup), so the gearbox can better handle power increases. This feature is important for helping a stock transmission (like ours) survive.
| The truck's ECM is removed so the Hydra Chip can be installed into the rear slot. Before setting the chip in place, the contacts on the ECM's circuit board must be cleaned. James connects the communication cables to the chip before installing it in the slot. It is then put into the plastic holder to be reinstalled in the truck. Note: The plastic mount that holds the ECM in place must be modified for the Hydra installation.
| Power Upgrade Modernizing A 7 3l Power Stroke 007
| Power Upgrade Modernizing A 7 3l Power Stroke 008
| With the ECM and Hydra installed, the truck is secured on the dyno again for another test. Before firing the engine, James downloaded six SDK Performance ECM calibrations (HeavyTow, LightTow, Tow, Daily, StreetRocker, and HippieKiller) into the Hydra and then set it on LightTow. This should provide a stock truck with a good power gain.
| The tune did bump up overall performance, but only to 253 hp and 568 lb-ft of torque. This is a bit short of our intended mark of 290 hp and 650 lb-ft of torque, which Charlie has seen with this configuration. A look at the dyno graph reveals a drop off in power, so Lead Turbo Technician Austin Seals inspects the stock setup for a boost leak.
| After checking the boost system and not finding any leaks, Austin removes the intake to inspect the turbo. There, he finds a damaged compressor wheel (caused by a thrust bearing with too much end play). The shaft easily moves in and out by hand, which is detrimental to a turbo's service time (its days were numbered). With a bad turbo, our dyno time is over. Had the turbo been good, the plan was to work in segments, with the injectors installed first and then the turbo, to record the progression of power gain.
| Power Upgrade Modernizing A 7 3l Power Stroke 012
| With a worn-out turbocharger, the engine is at its limit for power. After moving the truck to the back of the shop, James starts the upgrade process by removing the intake and charge pipes. With the charge pipes out of the way, the intake X-pipe is also taken off.
| Power Upgrade Modernizing A 7 3l Power Stroke 014
| Austin removes the valve covers and then pops out the rear injector on each bank to allow the injector oil galleys to drain into the rear cylinders. This makes it easier to clear the cylinders of oil before starting the engine.
| Power Upgrade Modernizing A 7 3l Power Stroke 016
| While the oil drains from the galley, the turbocharger is unbolted and removed.
| The next step is removing the stock turbocharger pedestal from the valley of the engine.
| The stock pedestal (right) supports an actuator that is used with the stock turbo's exhaust backpressure valve. Since the new KC300x turbo does not have an EBPV, the stock pedestal is replaced by the KC Turbos piece on the left.
| The rest of the injectors are dislodged from their seats with a prybar and removed.
| Austin unboxes a new injector and lays it on the table for a side-by-side comparison with the original piece. At a glance, the injectors are identical, but the Full Force Diesel Performance unit on the right is a Stage 3 Hybrid 205cc injector (the largest KC recommends using with the 300x turbo) with a 30-percent-over nozzle. These injectors feature tungsten-coated plungers and barrels, and their larger nozzles are engineered to provide better fuel-delivery control during combustion cycles. The Hybrid is designed to work with a stock high-pressure oil pump.
| Power Upgrade Modernizing A 7 3l Power Stroke 022
| Before installing the injectors, Austin attaches the oil deflectors he removed from the old units.
| The injectors are installed in the heads and then seated in place with a rubber mallet.
| Power Upgrade Modernizing A 7 3l Power Stroke 025
| The stock up-pipes and Y-collector are removed.
| On the right are the new KC Turbos up-pipes and collector. Bellows allow for heat expansion and are flanged (with gaskets) at the collector to provide better sealing than the stock pipes with compression couplings.
| The new up-pipe assembly is left loose to ease the turbocharger installation.
| The pedestal and new KC300x turbocharger are installed in the engine valley. KC Turbos' KC300x turbocharger is a journal-bearing turbo that uses a BorgWarner 300sxe-style turbine wheel. Ours had a 73mm turbine wheel and a 63mm compressor along with a .84 A/R housing for quicker spooling. The turbo was designed to be good for towing and all-around performance, so it should be a good fit for our truck.
| Power Upgrade Modernizing A 7 3l Power Stroke 030
| Before the turbo was secured in position, the up-pipes and downpipe were attached.
| The glow plugs were removed, and the valve covers set on the heads with two bolts to secure them in place. The engine is then cranked over to force any residual oil (from removing the injectors) out of the cylinders through the glow plug port. Valve covers were then removed and the glow plugs reinstalled. Normally when doing this type of work, the old glow plugs would be replaced for good measure. These were only a few months old, so they were reinstalled.
| The injector and glow plug wiring are run under the valve cover and the wiring harness plug is integrated into the valve cover gasket on 7.3Ls. It is a good idea to inspect the wiring and plugs for any damage that could cause issues later on. We went ahead and replaced all the old wiring and the gaskets with new replacement units from Sinister Diesel to ensure we don't have any wiring problems or leaks that would require us to remove the valve covers.
| With the turbocharger installed and the valve covers back on, we unboxed the Charge Pipe kit and Intake Manifold kit from Sinister Diesel. Both kits come with the necessary boots and clamps for installation. Also resting on the table is KC Turbos' (black) intake boot that's designed to work with the 300x.
| A look at the new intake manifold installed. Sinister's two-piece design is much easier to install than the factory X-pipe—and it looks good.
| Austin carefully installs the Sinister charge pipes. He then turns his attention to installing the intake boot on the turbo.
| Power Upgrade Modernizing A 7 3l Power Stroke 037
| Charlie installs a Big Honkin' Air Filter on the end of the intake to handle the new turbo's intake-air requirement. According to Charlie, the filter that was on the truck wouldn't have a high enough flow rate for the new setup.
| Power Upgrade Modernizing A 7 3l Power Stroke 039
| With the engine back together and a testdrive completed to make sure everything is working as it should, the F-250 goes back on the dyno to see what kind of numbers the modifications help the engine produce. Setting the Hydra on SDK Tune 6 (HippieKiller), the truck put down 453 hp and 960 lb-ft of torque (with 37-inch tires) before the power fell off. Charlie hoped for more power (closer to 500 hp), but the truck's stock fuel system is not up to the task. Upgrading the fuel system with a better lift pump will yield a power gain, but being able to more than double the stock horsepower and torque (with a stock fuel system) for less than $5,000 is a great update to an older truck. And a truck normally is not driven around with the ECM calibrated to the highest power setting.
| The dyno graph provides a comparison of the first run and the final run. Taking a look at the final run, it's easy to see where the fuel supply couldn't keep up at high rpm and caused the engine to hiccup a bit.