Need more power--try a better...
Need more power--try a better blower!
The popularity of Ford's current iteration of the Lightning is not at all surprising. Blessed with a sweetheart of a Modular motor, the supercharged 5.4 offers exceptional performance, despite the rather portly curb weight. Credit the massive torque production offered by the positive displacement Eaton supercharger for the Camaro-killing performance.
There is just something about having a healthy V8 with a positive displacement supercharger stuffed between the banks of the V where God and nature intended it. The look is symmetrical and the performance exceptional, just what we've come to expect from those lucky Fords adorned with an SVT badge.
This is a familiar site to...
This is a familiar site to Lightning owners, a supercharged 5.4 mod motor pumping out impressive power even in stock trim.
Perhaps the best thing about the Lightning, or for that matter, any factory machine equipped with forced induction, is the amount of power left on the proverbial table. Though additional boost is an easy route, the forced induction motor also responds better than its normally aspirated cousin to things like larger throttle bodies, mass air meters and free-flow exhaust systems. Where a Mustang GT or Cobra owner might be rewarded with 5-10 hp from each of these changes, the supercharged Lightning is looking at as much as 30-40 hp. Such are the benefits of ownerships of a supercharged vehicle.
That the Lightning is one impressive performer should come as no surprise to loyal MM&FF readers. The adventures of the Fridge have been well-documented. The supercharged 5.4 had been poked and prodded with a preponderance of performance products, soaring the power beyond the 400-hp mark (at the wheels, no less). Evan, Jim and the East Coast boys dug into the usual bag of tricks to persuade prodigious power from the pressurized pachyderm. Equipped with mass air meters, chips and exhaust mods, they finally resorted to that time-honored tradition of cranking up the boost on the Fridge to literally squeeze every last ounce of performance from the supercharged monstrosity. Toss in a few tricks like an electric fan and you have one serious power-monger on your hands.
The major source of all that...
The major source of all that horsepower is the Eaton M112 supercharger tucked under the inlet manifold.
Testing has shown that the stock 5.4 is more than stout enough to withstand the punishment, providing detonation is never allowed to rear its ugly head. In fact, the supercharged 5.4 used in the lightning will withstand every bit of boost the Eaton M112 supercharger can provide with room to spare. How do we know this you ask? Easy. We maxxed out the boost on the Eaton and then swapped on a new blower and ran it up even further. How far you ask? How does 21 psi sound? Need some more numbers? How does 522 hp and 600 lbs.-ft. of torque grab you? I take it we have your attention now, so read on.
You will remember that we recently ran a comparison test between the Eaton M90 supercharger and an Autorotor 1500 from Kenne Bell. The test was run on a 2001 Mustang GT equipped with a 4.6 supercharger kit from Saleen. The kit featured an Eaton Roots-style, positive displacement supercharger. Rigged with all manner of data logging equipment, we put the pair of positive displacement superchargers to the test, measuring inlet and outlet pressures and temperatures right along with specific power outputs. You will remember that the twin-screw Autorotor came out on top by a wide margin when compared to the Eaton M90 supercharger. The more efficient twin-screw Autorotor offered not only superior maximum power output, but also much lower charge temperatures. Airflow and efficiency are the trademarks of a good supercharger design.
Readers should also remember that we promised you a rematch using the larger M112 supercharger against a similar-sized Autorotor. Our sister publication Truckin' magazine provided us with the opportunity and we jumped at the chance for the rematch.
The M112 designation by Eaton...
The M112 designation by Eaton refers to the displacement of the supercharger in cubic inches. Note opening near the rear of the blower for top-feeding the supercharger.
Before beginning our blower...
Before beginning our blower swapadventure, the motor was baselined with a few minor mods. The opening in the fender well was modified to improve the flow into the factory air box.
The 1999 Lightning was upgraded...
The 1999 Lightning was upgraded to 2001 specs including the larger air filter assembly. The 80mm mass air meter was also updated to the larger 90mm meter used on the later trucks.
The exhaust system was modified...
The exhaust system was modified with a custom catback, but all of the testing was performed through the factory cat pipes.
Since we planned on cranking...
Since we planned on cranking up the boost, we installed Denso Iridium plugs in advance. We ran over 21 psi on the supercharged 5.4 motor with the stock ignition. These plugs really work great on force-fed motors.
Before beginning our tests,...
Before beginning our tests, the 5.4 mod motor was equipped with all manner of data logging probes and sensors. Vacuum fittings were installed at various positions along the intake tract in order to determine which component represented a restriction to airflow. Note the fitting used to indicate the flow potential of the factory (late-model) air box.
A second vacuum fitting was...
A second vacuum fitting was installed in the rubber inlet tubing between the mass air meter and throttle body.
Vacuum port number three was...
Vacuum port number three was positioned in the inlet manifold casting directly behind the throttle body.
We used one of the factory...
We used one of the factory vacuum fittings located on the back of the inlet tubing just before the air enters the supercharger. The four positions would allow us to isolate the source of the airflow restriction.