Words: John Dianna
Photography: Scott Killeen and John Dianna
Reprint from Super Rod Magazine, May 2002
THIS IS A CONTINUATIONOF THE STORY OF EXâ€¦ONLY THIS CHAPTER CENTERS AROUND THE EXCURSION, AND NOT THE EXPEDITION, EXPLORER OR ESCAPE, THE OTHER FORD TRUCK EX SISTERS. THIS SAGA IS ABOUT THE BIG ONE, THE SUV THAT WEIGHS MORE THAN TWICE THAT OF A PERFORMANCE PONY CAR. IT ALSO IS ONE THAT IS RUGGEDLY BUILT, PERFORMANCE INCLINED, ESPECIALLY WITH THE POWER STROKE DIESEL OPTION, AND COMFORTABLE AND ROOMY ENOUGH FOR A FAMILY OF EIGHT. THE EXCURSION IS EQUIPPED TO TOW A SUBSTANTIAL 11,00 POUNDS, AND WHEN OUTFITTED WITH THE 7.3 DIESEL POWER STROKE, WILL PULL LARGE TREE STUMPS WITH THE MIGHTNESS OF ITS 505 LB-FT OF STUMP-PULLIN’ TORQUE.
Now that we have a few years’ experience with Ford’s Power Stroke diesel, we have grown increasingly fond of its power characteristics, as well as its exceptional driveability. We have grown to appreciate this powerplant much more than we ever
thought imaginable, and, frankly, because of our penchant for boating and car shows, we would find towing difficult with anything less.
Diesels are traditionally workhorses, built never to let you down when the duty chips are high and stacked against most mortal transportation. They are used in the most demanding
of industrial applications, and are depended upon to propel ships and over-the-road trucks, as well as tractors and earthmovers and such. These are mighty man-type engines, and traditionally have been built for the sole purpose of ruggedness and low-rpm usage, and damn the weight of such might.A large 600hp in-line boat diesel engine, such as a Detroit, can weigh close to 2 tons, and a boat of “size” will generally use two of these. But if you treat it right and provide the filtration and clean oil, it can run for a very long time, especially the Ford Power Stroke. Aside from power-tuning the engine and regular oil and filtration changes, our Power Stroke F-350 dualie has yet to see a Ford dealership or need a single part. It has crossed the continental U.S. more than four times, and has lived a good deal of its life in the high desert.
Nicks Old Car Specialty did the extensive bodywork. Here you can see that the front bumper was cut and a piece was added to flare out and match the new, wider wheel flares.
The front fender flres were also lowered to sit down over the rather large Toyo Proxes 305/45R22 tires and 22×10-inch Boyd Coddington billet wheels.
The same procedure was done for the rear wheel flares. They were lengthened and widened, but still look stock.
Since its introduction, the Power Stroke diesel has sold in the millions. It rendered the Cummins Dodge package nearly obsolete and sent GM back to the drawing board and to an all-new Isuzu diesel that now more aptly power the big Chevy pickups. What makes the Ford so powerful is its packaging, its fuel management and the general underrating of the engine. Underrating an industrial-type engine is common practice, and there are numerous ways to cut back unneeded power. This can add greatly to the dependency of the powerplant, particularly when its cycles are spent well below the max-rpm line, although these engines are really built to operate at their rated engine speeds, and for extended periods of time. As long as you do not allow the exhaust gas temperature to rise near the melting point, or flow the fuel to enable the engine to “run away” with itself, the Power Stroke will provide miles and miles of trouble-free service. As an example, the engine is rated at 250 hp at 2,600 rpm, and will
produce a staggering 505 lb-ft of torque at a lumbering 1,600 rpm, but you can expect an easy 50hp increase at the rear wheels with a simple chip exchange. When equipped with an exhaust gas temperature gauge (Pyrometer)-it is a good idea to on install one-you can learn to operate the engine, even while towing, well within its thermal limits, and run it all day long. More on that later.
This engine combo makes the Ford big-truck package a great hauling and towing truck. We use ours for boat and show-vehicle towing. The boat, a 25-foot Baja speedster, with the trailer and accessories, weighs about 8,000 pounds, the street rod and trailer considerably less. This truck doesn’t flinch, and has pulled either load through the mountainous California high desert on our way to the warm desert lakes and faraway car events without a single letdown.
Here, you can begin to better understand the extent of modifications done to the rear suspension to add the Firestone 4,000-pound (per pair) double-convoluted bags. The leaf springs were retained, but modified.
Much is available in the way of modifications for this diesel to make the hauling chore that much more enjoyable. You can add bigger turbos, a larger 3-1/2-inch or 4-inch dump pipe, from the turbo to the exhaust (stock is slightly over 3 inches in diameter and is flattened), straight-through aftermarket muffler and big-tube exhaust of the 3-1/2-to 4-inch variety. We have seen larger, but it’s doubtful it is necessary without larger injectors, tuned-up fuel pump, propane and other exotic diesel horsepower builders. All this will no doubt allow you to build something near 500 hp, but will greatly alter the driving characteristics of the diesel, and will most certainly void your warranty. And don’t expect to do this successfully without supporting the rear axle and spring assembly to better control its movement under hard acceleration. The converter and
The air suspension and the two air tanks were munted on the outboard side of the driver’s-side frame. Note the custom mounting brackets to house equipment.
transmission are also concerns, but both can be beefed up accordingly.
Intercooling and electronics are key items to a stout-running turbo diesel, at least for those that are computer controlled, such as the Power Stroke. Electronic fuel management can help to turn up the wick on a diesel, and the intercooler will ensure a lower temp and that a more densely compacted air charge will be atomized with the kerosene and briskly arrive at the combustion chamber igniters. Diesels can be a lot of fun. They readily respond to the stuffing of more fuel and air. So, when you begin with 250, by adding an easy 80, you quickly realize a 32 percent increase in useable power, and that can be an impressive ride.
Couple an increase in power output with the flexibility of a bolt-in Gear Vendors Under/Overdrive unit, and you
have the makings of a highly adaptable, powerful package that will perform in nearly any environment. The GV unit was easy to install, and other than following the generous instructions, the only extra step required is the shortening and balancing of the existing driveshaft. We will show you all this in the next installment, but as far as we are concerned, we couldn’t conceived of owning this package without one; it is that versatile.
For the engine basics, the most inexpensive way to allow more air to the engine is to increase the air filler arrangement. The next step is to replace or reprogram the computer chip with one that will manage the fuel curve more aggressively. There are also the portable computer modules (controllers) that, instead of replacing the prom, plug into the diagnostic loop, read the existing chip and reprogram it with a more active curve. These control modules are available with one or more programs, adding 50, 60 or 80 hp. There is also the three-position manually controlled-type chip that requires a simple one-hour installation, whereby the assembly replaces the original prom and, through a flat-ribbon cable, attaches a manually operated three-way toggle switch. With the flip of a switch, you can, add, say, 60 hp, or flit it again for an additional 80 hp. For those of you who demand more and are serious about building exhaust-temp heat, a stock-80hp-100hp configuration also is available. TTS Power Systems offers this switchable chip, as well as the single-program models. The tri-position chip sells for $695 and the single retails for $495.
Left: The Brake Man Tornado calipers are massive, quite nice looking and a good addition to the hefty Excursion, especially when it is in its towing mode. Stopping this rig should be a major safety concern. Center: The Hurricane rotor is matched for a balanced yet aggressive front brake system. Right: These big brakes fit well within the big wheels, as the stockers look like weed-eater discs.
We have not finalized our ship install because, thanks to Rick’s RV in El Cajon, California (619/440-7253), we have been involved in a series of dyno comparisons to seek answers to what works and where, and just how much more driveability and towing power you get for your dollar. With Rick Preston’s personal overview, we are now working through a variety of chip designs, but, as of this writing, we have not finalized our dyno flog. We hope to complete this phase of our analysis for the next issue, so stay tuned. We can tell you that with the installation of a 60hp Super Chip, we netted an increase of 55 hp at the rear wheels, and nearly double the torque, but this has not been A-B-A tested, due to dyno-hookup shortcomings.
The intercooler on the new Fords is a new and improved design, and is said to be larger in capacity and contain smoother internal radius turns, thus more cooling efficiency. Large aftermarket coolers also are available, but we don’t expect much from an upgrade here, unless you have further hopped up the engine by turning up the fuel pump, enlarging the injector nozzles and modifying the turbo itself. If you so desire, you can nearly double the power output of this engine, but engine life, driveability and transmission dependability will suffer. It is quite a kick to power away from a stoplight with one of these 7,000-pound packages, watching the startled look on
the kid’s face sitting in the car next to you. Who would expect such performance from a vehicle of this size?
But anything over 60 hp is a mighty big jump, particularly at the rear wheels, if the chassis is left stock. Additional power, more than 50 or 60, requires attention to the rear springs to handle this much added power, or spring wrap-up and housing flutter can result. Our suspension modifications, while nearly complete, are still a work in progress. We continue to develop the working package as we go, and now need to fabricate a set of under-leaf rear bars, similar to the old Traction master bars that connect the axle housing centerline at the spring pad area to the front spring eye. This will triangulate the housing movement rotation and control spring coiling. Our homemade device will be built using large heim joints, flat plate and thick-wall tubing with adjustable threaded ends. This addition will not stiffen the ride, nor will it bind the rear axle assembly, but will allow us the ability to soften the rear spring even more, thus lowering the static height of the vehicle, through a combination of leaf removal and/or de-arching. Part of the overall suspension objective, ride height and control, is the addition of an Air Ride Technologies airbag system. Our intent was to drop this baby on the ground and stuff its fenders full of tires and wheels. We did this, but subtly, and in a manner that looks a bit more exaggerated, but as if
it belonged that way when new.
To begin with, no full-line suspension kit existed when we started this project. Dropped front I-beams are available from AIM Industries and DGM, although the approach that each took in its design is completely different. AIM designed its beam structure from flat stock, and it is welded with gussets, while the DGM I-beams use a series of round tubes, one welded within the next. If ours was to be a single-vehicle driver, we would have opted for one or the other, but because our total towable package weight would be approaching 16,000 pounds, we stuck with the massive forged factory I-beams and modified the suspension instead. Our needs required the addition of airbags at all four corners, so the towing height, as well as the unladened ride height, could be adjusted with the push of a button. Rick’s RV examined our Excursion and the Air Ride Technologies F-350 dualie front and rear airbag suspension kit we brought along to see what could be make to work. The Excursion and the F-350 dualie may look like similar trucks, but they are not. We also complicated matters with a new, larger front brake assembly built by The Brake Man (805/987-7867), which was a basic prototype design. We were treading uncharted territory with regard to how all these massive parts would fit within the tight confines originally designed for OE production parts.
Because of Rick’s vast experience with airbag systems (keeping large motor homes on the road, and upgrading the chassis on these rigs), the shop knew that some modifications would be required. Rick’s started with the front assembly and the challenge of fitting the 22-inch Boyd Coddington wheels and massive Toyo
Above: Rick’s RV does custom rod interiors, so after mounting the Gear Vendors Under/Overdrive manual-control module, the shop added a “Buckaroo” motif to the trans tunnel carpet cover. Upper Right: J&J custom stainless
doorsills also carry the “Buckaroo” logo. Right Center: Add a rear-hatch Buckaroo logo, and you get the idea. Lower Right: The Carriage Works grille and surround adds a wider look to the tall truck. Far Right: Nicks also covered the unsightly low hitch.
Proxes 305/45R22 tires under the lowered chassis within the wheel wells, adjacent to the rubber bag casings and around the large-diameter Brake Man Hurricane rotors and Tornado calipers.Rick’s installed the ART front suspension parts, which consisted mainly of new airbag mounts that replaced the original spring seats. Rick’s found that, due to the centerline of tire and wheel, when compared to the larger, offset wheel hubs of the dualie, interference with the bags
resulted under certain dynamic and bag-pressure conditions. And this in spite of the fact that we offset the one-off Boyd Coddington wheels further to the outside by 1 inch. We made this decision to clear the massive Brake Man front calipers. This created further interference, when lowered, with the top of the inner fenderwell and the outer wheel lip of the fender.
At the rear, because of a lot of structural and component interference,
and the springs, the four-bar dualie installation kit would not work at all. Instead, Rick fabricated his own airbag installation, in much the same fashion as that of a motor home. He used 2×6-inch rectangular tubing and flat plate to mount the lower bag brackets. The stock mounts were retained but were moved to clear the airbags.
The rear springs also were retained, but three leaves were removed to lower the vehicle. The actual number of leaves and their proper contour will be determined as a result of real-world driving in all conditions, normal driving and towing. The airbags Rick used are the same used by ART, double-convoluted, 4,000-pound-capacity (per pair) Firestones.
We sought a certain look, so discarded the plastic cladding in a contrasting beige and had to deal with the sheetmetal of the truck. Following the design scheme created by Gary Constable of Mutant Art, and with sketch in hand, we drove our
Excursion to Nicks Old Car Specialty in Redlands, California (909/798-1078). Harry Nicks agreed to what we wanted to do, and he lowered the fender opening and at the same time flared it wider, both front and rear. This necessitated widening the front bumper to match up with the wider, recontoured fender lips. We also had Nicks form a metal cover around the tow-hitch assembly, to hide the square tubing hanging beneath the bumper. The bumpers were stripped and painted black, and new Cord running boards, with dual courtesy lights, were installed. Nicks completed the metalwork and installed the Carriage Works grille and open grille surround. Nicks then repainted the truck black, and it was final color-sanded at Rick’s RV.
A custom set of personalized, J&J stainless doorsills, made expressly for Buckaroo, finished off the mods, and they make for a welcome entry into the plush 146.4-sq.-ft. eight-passenger interior. The Limited Edition package is well equipped. The leather seat coverings, the easy-to-fold seating and the layout of the instrumentation and controls have been well thought out. The tri-fold rear door is
both convenient and easy to use, and the two side doors open back nearly 180 degrees.
Overall, we are pleased with what we have done thus far, but there is more to do. In our next installment, we will show you the brakes, the final suspension mods, the Gear Vendors Under/Overdrive install, as well as provide you the insights on what we have managed to accomplish on the dyno, powerwise. Currently, the 55hp upgrade has made a considerable difference, and the big but low and blacked-out motif has provided an alternative to the Big and Bad theme, and it works for us. SR