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The Plan
Head snapping horse power, hill flattening torque and vapor sipping fuel economy was our main focus when selecting components and making adjustments. Sometimes we found that a certain combination yielded less of a result than anticipated, so other options were investigated until the "best of the best" was revealed for this particular application. Sometimes, this changed as new items were installed, thereby changing the performance of previously installed components. It was a real chore to keep these little things from slipping from our goal of getting the absolute maximum we could, with what we had. 

(Photo of truck front): When we set out to see if it was possible to nearly double the fuel mileage and at the same time increase horsepower of a given test rig, we made sure it would be the toughest test to date. And by starting out with a big-block powered, one ton, four wheel drive,  four door crew-cab dually, that certainly ended that search! The Centurion company of Michigan produced this 1988 factory conversion by mating a pickup front half with a Bronco back half. And, we were very comfortable during our long over the road tests, to say the least!

(Photo of truck rear):
With nearly four tons of Rolling weight, six tires on the ground, almost twenty feet longs and over eight feet wide, this mammoth of a truck was sure to promise a severe workout for anything we could throw at it. We were not disappointed. Even though this rig may not be exactly (or even remotely) similar to what you have, the principles are basically the same and the results will give you a good idea of what you may want to install on your particular setup

(Photo of truck interior): While traveling all over the country during the testing of this project, we received curious looks and numerous questions on our unique vehicle. Inside, captains chairs, stained Oak woodwork and accents pleased the creature comfort angle, while a host of electronic gadgetry and gauges kept us informed of our progress. A cell phone, color TV, VCR, scanner, laptop computer ands even live 110 volt AC power on board kept passengers busy in the back seat.

(Photo of truck w/laptop in front seat): With our Pentium powered laptop computer on board, we set out to do our rear wheel horsepower, acceleration and fuel mileage tests. Calculated horsepower and torque figures were obtained using the Performance Trends Performance Analyzer software, resulting in extremely accurate readings in comparison to each other. A Vericom unit was used to back up these test figures as well. An initial test was calibrated to a known factory standard, whereas we used this as our baseline. As per the rated factory output (on an engine dyno), our 460 was listed at 230bhp @ 3,600rpms and 390ft/lbs torque @ 2,200rpms at the flywheel where as our figures were rated at the rear wheels. For comparison sake, one could estimate that the flywheel figures would be roughly 20% more than that of our rear wheel results.

(Photo of gauge cluster and air-temp readouts): During the tests we monitored all the vehicle's vital signs from air intake temperature and exhaust, to fluids and under hood temps. In this manner we could accurately duplicate test conditions from day to day. These instruments, along with the on-board laptop computer made the testing procedure a breeze.

(Photo of temporary tach installed): We also installed a calibrated tachometer to insure correct test readings along with calibrating the speedometer as well. We instantly discovered our factory in-dash tach varied almost (either high or low) as much as 400 RPM's way too much to be an effective instrument to measure our tests with.

(Photo of installed batteries w/wrench): Before getting Project M-P-G underway, we needed to insure that the engine and suspension were not doing any extra work which would take away from the fuel mileage potential. We installed two fresh interstate batteries boasting 850cca and 120 minutes reserve capacity each, which will insure that our alternator will not be working "overtime." Interstate's Mark Love mentioned  we could leave our radio on for 50 hours and still be able to start the engine!

(Photo of installing shock, w/ top going in): For providing maximum ride comfort and eliminating all possible wheel hop in our tests, we chose the Rancho 9000 adjustable shocks on each corner. One of the many advantages of the cellular gas design of the 9000, is it can be installed 'upside down' in order to facilitate easy access to the ride control dial. The 9000 can effectively be adjusted from as light as the equivalent of half of a normal shock all the way up to 5 shocks... all in the flick of a wrist. Or you can even opt for the in-cab remote controller to adjust all four on the fly.

(Photo of Code Scanner testing engine): First things first, and that is to insure that our sophisticated computer management system is doing it's job. This handy little tool called a Code Scanner available from Sun-Pro can be had for around 40 bucks, and plugs into the vehicle's wiring harness at the diagnostic port which leads directly into the engine management computer. The Code Scanner told us that our Oxygen Sensor was reading a little on the lean side along with the EGR valve not seating properly. After confirming these problems and repairing them, we were on our way.

(Photo of setting TPS voltage setting): For maximum throttle response and accurate fuel metering, it is imperative that the Throttle Position Sensor be accurately adjusted. The Ford manual tells us that the voltage setting should be .998 volts, where ours was less at .987. A quick twist of the screwdriver got us back in shape in a hurry. Note that we did NOT pierce the wires with test probes, but rather slid back the weather seal instead. Allowing moisture to enter the wiring of any computer controlled engine management system eventually could lead to improper readings, therefore creating unforeseen headaches and problems for the life of the vehicle.

(Photo of setting TPS idle position): Even though our rig was running good (or so we thought), we did a detailed inspection on our engine anyway. Although our plugs and cap looked good, we felt putting new ones in were cheap insurance in extracting every ounce of performance out of our engine as possible. Before doing any tuning, we needed to check our Ford big block's base idle setting which involves removing the air bypass valve sensor plug (the horizontal metallic tube seen below the intake hose) and setting the idle plate stop screw to read 650rpm on the tach without the computer intervening. We set ours at a slightly higher 750rpm's to help keep maximum alternator output at idle. The connector was plugged back in and we were ready to move onto the next procedure. Contact your dealer to find out what your vehicle's individual procedure involves. Of course, pre-EFI engines will not need to perform this task.

(Photo of timing plug removal): Before checking or setting the timing, the spark output (or SPOUT) connector needed to be removed from our Ford. This disables the computer from trying to correct the timing at the same time we were making the manual adjustments.

(Photo of setting timing): Once the SPOUT connector was removed, the initial timing was increased from 10 to 12.5 degrees. Just enough to be noticeable, but not too much as to cause pre-ignition and make the engine ping. Too much of an increase, and the ever probing computer would electronically retard the base timing back to where it thinks it should be, therefore losing any benefits, and then some.

(Photo of spark plugs, dist. cap, rotor, and plug wires): Fresh Motorcraft plugs were used due to their known tendency to shut off the spark before burning a piston if a dangerously lean condition arose. Moroso Blue-Max Spiral core wires were chosen in light of their ultra-high quality and real wire used in the windings, along with their direct fit applications. We discovered our old wires showed nearly ten times more resistance on an ohm meter as compared to the new Blue Max wires. A new Borg Warner gold terminal distributor cap and rotor were also added to round out this under hood tune-up package.