Part Four: Horsepower. Finally.
Now into month 6 of ownership of this classic old body style 227,000 mile Ford F350 and we’re starting on the fourth installment of the project build up we plan to fill quite a few issues of Diesel World with. We started this build in hopes of making some great content on some of the ins and outs of these old 7.3L Power Strokes. Show of some of their strengths, point out some of the weaknesses, and help you guys, like us, that still have a weakness for these old trucks. Sure, they’re a little outdated, but they can still be great trucks, with the right amount of love and attention. No, they don’t make the power new trucks do. Yes, they run a little on the loud side compared to a new truck. And No, they don’t ride like new coil sprung and air bagged trucks do. But we know there are plenty of guys out there that just love these OBS Fords, it’s a nostalgic truck that just won’t ever go out of style. So why not appreciate that about them and build something unique and classic, instead of just another 2018 showroom floor model with some shiny wheels and stretched tires.
In part one, we worked on some cosmetics, updating the front end with new lights, chrome, and grille. Part two brought interior upgrades with a new dash, some sill plates, and door hinge repairs. Part three was basic repairs like fixing a leaky oil dipstick, installing an in-cab monitor and cold air intake. So finally, in part four we’re going to focus on bumping up that factory 225hp flywheel rating to something that could help get this land yacht down the road with some decent drivability and acceleration.
One of the most common first mods a diesel owner will make to his truck is an upgraded exhaust system and for good reason. While an aftermarket system will help give off the throaty sound, we all love, on the 1994-1997 Power Stroke trucks, the right 4” system, like the Monster Exhaust kit from Banks Power is an actual performance upgrade too. For a reason we’ll never fully understand, the Ford engineers used a nearly flat and pinched off factory down pipe piece to get exhaust from the turbocharger outlet, down past the engine and firewall to the underside of the truck, where their true exhaust system starts. With plenty of room their to work with, Banks engineers developed a true 3” mandrel bent downpipe that outflows the stock piece by 26%, which reduces turbo back pressure and equates to better engine efficiency and cooler exhaust temperatures.
The Banks exhaust system will retain the factory catalytic converter (yes, the government requires you to keep this) then flows on to a massive high flow Monster muffler that will help reduce cruising speed drone, thanks to a special noise chamber while offering a great rich sounding exhaust note from the tailpipe. These kits are constructed of stainless steel thick wall full 4” mandrel bent tubing and will most likely outlast the truck your bolting it on to. The fit and finish is near perfect, with the tailpipe exit kept up tight against the body offering a clean classic look with a little pop of style from a rolled edge 5” polished tip. Since these trucks were never intercooled from the factory (something we’ll get to soon), EGT control with performance tuning can become a challenge, so the new downpipe and 4” system will be of great benefit when it comes time to try and tow and use the soon to be installed horsepower in a switch.
AA Design Tuning
When this truck was brand new, there weren’t many ‘chip’ upgrades available, but with time the aftermarket came out with some pretty neat stuff in the early 2000’s and the Superchips MicroTuner we found stashed behind the back seat was one of the most popular tuners every released for the 7.3L platforms. Back then, this performance tuning could add a decent 40-60hp in a stock truck and owners couldn’t believe what they had. But flash forward to our current day and age and custom tuning options for this old platform has blossomed into quite the market.
For years, companies like Power Hungry Performance (PHP) have devoted thousands and thousands of hours into the 7.3L market and have been running custom hardware that plugs direct into the PCM through the factory J3 port found on the computer board. The latest hardware technology from PHP comes from their Hydra Chip, which will allow custom tuning from just about any shop with experience and the ability to write files in their software to flash multiple tunes into the chip for on-the-fly in cab control. An easy to read digital display shows you which tune file you’re running, while an optional USB cable will allow easy tune reflashes without ever pulling the chip out of the truck again. PHP offers hundreds of base calibration files for otherwise stock truck at no extra cost, but to get the most out of your truck, custom tuning can be worth the extra cash to help fine tune the transmission and engine parameters to meet your build specifications.
For this build, we opted to call up an old friend from years back, Andrew Craig at AA Design & Tuning in Green Acres, WA. Craig has been specializing on Power Stroke performance for years and has spent a lot of time working on these old trucks and has a real knack for dialing in the engine and transmission strategies to squeeze out every ounce of performance, safely and efficiently. With the PHP hardware and their downloadable software, we were able to flash the Hydra chip with custom files AA Design compiled for us using information we supplied him like tire size, gear ratio, performance modifications, transmission modifications and our trucks PCM code. We have a stock file, hi-idle, light and heavy tow tunes, daily driver, and a pair of performance files to choose from to suit just about every driving situation. The tow tunes offer great shift patterns to keep a heavy load moving, while the daily driver economy tune has great throttle response and pep for stop and go style driving. As an added advantage to the custom tuning, smoke output is completely controllable and even our Race file can be driven with nothing more than a whisp of smoke from the tailpipe.
The 1994-1997 trucks were rated from the factory with 210-225hp depending on the model year, with this truck being a California Emissions model, it was rated at 225hp/450tq flywheel thanks to the 120cc split shot injectors. While the 49-state federal trucks used a smaller 95cc single shot injector capable of around 210hp/425tq. So with drivetrain loss, these model year trucks will land in the 170-190hp range on a chassis dyno. With our previously installed S&B Filters cold air intake, the new 4” Banks exhaust and custom tuning from AA Design this truck rolled 306hp on a respectable Superflow dyno ran by the Northwest Dyno Circuit. While we didn’t dyno the truck stock, it’s safe to say we’ve bolted on a solid 100+ horsepower and 200lb/ft of torque. This helped improve drivability, offered better turbo spool-up, improved throttle response and better transmission shift strategies and line pressures allow us to use the power we’re making more efficiently. We’ve seen a mild increase in fuel mileage to boot. No we’re nowhere near the 475hp/1050tq Ford just released on the 2020 6.7L Power Stroke, but to be quite honest, those are numbers we totally plan to match and even surpass in this old girl. Stay tuned.
AA Design & Tuning