The stock inlet casting was...
The stock inlet casting was used with both the Eaton and Kenne Bell superchargers.
The 1999 Lightning used for testing was recently upgraded with late-model components including the 2001 processor, air filter box, 90mm mass air meter and intake/intercooler assembly. The revised intake runners required a different bolt pattern, thus a different supercharger. The difference between the older and later M112 superchargers appears to be just the bolt pattern for mounting.
The late-model (2001) intake manifold was definitely different, offering from 3-5 inches of additional runner length (depending on where you measure it). Just to satisfy our own curiosity, we ran a test using the older processor and 80mm MAF on both the older and newer intake designs and found no significant power gains. Apparently 3-5 inches of runner length (from 0) offers very little in the way of a ram effect on a motor that only revs to 5500 rpm.
Oddly enough, the addition of the late-model components offered very little in the way of extra power over the stock processor, intake and MAF. In fact, we witnessed a slight loss after the installation (go figure). Undaunted by this bizarre turn of events, we established a baseline using the late-model components at 348 hp. (Truckin' had previously modified the Lightning with an aftermarket cat-back exhaust which seemed to help power. The stock cat-pipe was left intact.)
Part of the update kit to...
Part of the update kit to late-model specs included a new intake manifold and (wider) intercooler core.....
The idea behind the story was to demonstrate the effectiveness of the Autorotor supercharger as a replacement for the Eaton. While it is true that a considerable amount of power can be coaxed from the supercharged 5.4 with the Eaton supercharger, every supercharger has a limit to the amount of power it will support. Once you reach the flow limit of the supercharger, you have no choice but to replace it with a better flowing unit.
While you are at it, why not add efficiency and a lower charge temperature to boot? The opportunity presented itself when Kenne Bell decided to offer Lightning owners an alternative to Eaton power. According to the folks at Kenne Bell, the supercharger upgrade would allow Lightning owners to easily exceed even the maximum power available from the Eaton. As an added benefit, the Autorotor would also provide lower charge temperatures and would even require less power to drive.
The theory was that the blower replacement would provide an immediate power gain over the Eaton while offering the potential of serious performance if the Lightning owner were so inclined. Having seen the impressive power offered by the 5.4 Lightning engine in stock and especially modified form, we were intrigued to say the least. The test would allow us to not only check out the power benefits offered by bolting the Autorotor in place of the Eaton, but would also provide the availability for some efficiency testing. With data logging equipment at the ready, we could use this opportunity to monitor inlet restrictions, boost pressure before and after the intercooler, temperatures before and after the intercooler, water temps, spark advance and a number of other variables. This information could then be correlated with the appropriate dyno results for a better understanding of what really happens when you crank up the boost.
Check out the difference in...
Check out the difference in runner length between the early (upper) and late manifolds. Testing showed that the slightly longer runners had no effect on power over the early (short-runner) design.
And crank up the boost we did, not just by a couple of pounds mind you, but by more than 100 percent. That's right, installing the Autorotor upgrade from Kenne Bell combined with the excellent (upgraded late-model) air-to-water intercooler allowed us to exceed 20 psi. The extra stout Lightning motor came through all the testing without a scratch--a real testament to the strength Ford put into the motor combination in the first place.
The first order of business was to establish our baseline power output. After hooking numerous probes, sensors and thermocouples to the various inputs, we ran the engine in baseline trim. Baseline trim included the late-model upgrades and a modified cat-back exhaust. The factory cats, injectors and pump were left untouched for the remainder of the testing. Impressive is the only word that can describe the ability of the factory fuel system to cover our spread of 150 plus horsepower without signs of running out of steam. Equipped with the Eaton M112, stock 7.5-inch crank and 3-inch blower pulleys, the Lightning motor produced a peak of 9.3 psi and 348 horsepower at the wheels.
Now it was time to crank up the boost. After a few pulley swaps, things started to get interesting. Johnny Lightning helped out greatly by supplying us a trio of crank pulleys. The aluminum replacement pulleys measured 8.5, 8.75 and 9 inches in diameter. The 9-inch crank pulley looked downright huge.
The 90mm meter offered superior...
The 90mm meter offered superior airflow compared to the early 80mm unit.
Rather than bore the readers with all the power gains offered by the various steps in pulley sizes, let's cut right to the chase. The power increased at a rate roughly slightly over 10 hp per pound of boost.
After we installed the 9-inch crank pulley, the boost increased to 13.4 psi and the peak power jumped to 396 horsepower. Increasing boost pressure by just over 4 psi resulted in a gain of roughly 50 horsepower over the baseline runs. We tried a smaller 2.75-inch supercharger pulley on the Eaton, but the results were a less than dramatic 2-hp gain.
The Lightning came equipped...
The Lightning came equipped with 42 lbs./hr. injectors capable of feeding in excess of 500 hp at the wheels.
Check out the data logging...
Check out the data logging equipment employed by Kenne Bell during the testing. A scanner, a laptop computer, a printer and a Horiba real-time air/fuel monitor were employed along with the information supplied by the DynoJet.
A large fan was used to keep...
A large fan was used to keep thetemperatures constant during each run.
Equipped with the stock 7.5-inch...
Equipped with the stock 7.5-inch crank and 3-inch blower pulley set-up, the 5.4 pumped out 348 hp at the wheels at 9.3 psi.
Swapping the blower pulleys...
Swapping the blower pulleys on the Eaton was a real chore. In the end, it was easier to change the entire snout assembly rather than attempting to remove the pressed-on pulley from the snout.
The stock crank pulley was...
The stock crank pulley was ditched in favor of a 9-inch aluminum pulley from Johnny Lightning.
Eaton M112 vs. Autorotor(Kenne...
Eaton M112 vs. Autorotor(Kenne Bell Bolt-on Lightning Kit)
Want to add 50 extra horsepower to your supercharged 5.4 Lightning? That's exactly how much power we got when we installed the supercharger upgrade kit from Kenne Bell. The KB upgrade kit was designed to replace the factory Eaton M112 roots-style supercharger with the more-efficient twin-screw design from Autorotor. As is evident from the power production, the Autorotor offered a significant boost (excuse the pun) in performance. For this test, both the Eaton and Autorotor were installed using all of the stock hardware including the stock air box, MAF and inlet manifold. The twin-screw supercharger was even equipped with the same 3-inch blower pulley used on the Eaton it replaced. Even with the same crank and blower pulleys, the Autorotor increased the boost pressure from 9.3 psi to 13.2 psi. Interestingly enough, even with 4 additional pounds of boost, the charge temperature exiting the Autorotor (before the intercooler) was slightly lower than the Eaton at just 9.3 psi. Though a 50-horsepower gain was impressive, we were to find out that the Autorotor was just getting started.
Eaton M112 vs. Autorotor(9...
Eaton M112 vs. Autorotor(9 psi vs 9 psi)
I included the results of this test for those individuals (there are always a few) thinking that Test 1 was skewed due to the difference in boost pressure. The reality is that the two blowers are very comparable in displacement and the true test is to spin them at identical speeds relative to the motor. The Autorotor should not be punished because it flows better than the Eaton, but I included this test anyway to satisfy the roots-style fans. To produce identical maximum boost levels, we removed the 3-inch blower pulley from the Autorotor and installed a larger 3.50-inch pulley to slow the blower speed and reduce the boost. Even fudging the test by slowing the Autorotor, it outpaced the Eaton by 16 horsepower. Credit a better flow rate and less parasitic loss to drive the blower for the power gains. Even run boost for boost, the Autorotor MX420 demonstrated its superiority over the Eaton M112.
Max Power with Stock Air Box...
Max Power with Stock Air Box
This graph illustrates what happened when we cranked up the boost on the Autorotor. The supercharged 5.4 Lightning mill impressed everyone present, not just with prodigious power but also with the ease at which it was obtained. We wanted to demonstrate what kind of power was possible with the stock air box, MAF and throttle body in place. To that end, we installed a 2.57-inch blower pulley and a 9-inch crank pulley from Johnny Lightning. The combination resulted in a whopping 19.8 psi of boost. With the stock air inlet system, stock injectors and stock fuel pump, the Lightning cranked out a whopping 482 horsepower. The vacuum gauges we installed on the inlet system (see photos) indicating that the stock throttle body, MAF and air box were restricting the motor to the tune of 5 inches. That is an astronomical amount of restriction in any intake system. That the motor produced 482 horsepower with that kind of inlet restriction was a sure sign of things to come. The lower graph indicates the stock power level of the 5.4 equipped with the Eaton. The stock output is only used as a reference point to demonstrate the massive power potential offered by the Autorotor.