In the seemingly never-ending search for more power, there are many options. Supercharging is one, and it makes an engine work as if its bigger than it really is by forcing more air into the cylinders than atmospheric pressure alone can do. That part of blower history hasnt changed, but the compressors themselves sure have. It used to be that noise, overheated intake air, and bulk were among the trademarks of a puffernot so with the new Eaton units.
With only ¼ hp of parasitic drag, 68 percent efficiency, and a conservative 30 to 40 percent increase in performance at a 5-psi boost (according to Allen Engine Development), the small Eaton-based blower sure looks good compared to the big old cog-belt setups from an efficiency standpoint.
Blowers have made a quiet (literally) comeback on cars, many of which leave the factory with an Eaton supercharger under the hood. Since stuffing more air into the combustion chambers of a four-wheel-drive has the same effect on performance as it does on a lowly car, it makes sense that someone would apply this newer blower technology to four-by engines. And that someone is Jerry Magnuson of MagnaCharger (supplier to Allen Engine Development).
Having tinkered with blowers since the 60s, Magnuson pretty much knows what works and what doesnt, and MagnaCharger is the sole North American remanufacturer of Eaton superchargers as well as handles aftermarket applications of the popular huffers.
Most of the Allen setups are California Air Resource Board (CARB) legal, made to work within the stock fuel parameters. The installation shown in this story was a prototype for a 1999 F-250 with a 5.4L V-8. Thanks to the small size of the Allen combo, the blower was practically hidden from view once it was installed under the new intake manifold. Harder to hide, at least whenever the throttle is applied, is the 38 percent increase in horsepower that has resulted.
Those who feared that bolt-on power, especially in large doses, was doomed with the onset of ever more stringent smog laws can rest assured. Blowers are obviously here to stay, pumping new life into mediocre motorsor some more yet into engines that run well to start with.
Blowers are a time-honored...
Blowers are a time-honored way to make power in internal-combustion engines, but the latest offerings, such as this Eaton, were never intended to provide breathable air in mine shafts. Instead, tight tolerances and improved technology have made possible very efficient units that eliminate most of the drawbacks normally associated with supercharging.
In factory form, this 1999...
In factory form, this 1999 F-250's 5.4L put a not-so-impressive 146.3 hp (at 4,500 rpm) to the rear wheels. That may fly in a stripped Mustang, but a four-wheel-drive crew cab with a hitch deserves more. The stock manifold and everything attached to it were removed to make room for the Allen setup.
In all its simplicity, this...
In all its simplicity, this throttle used between the blower and intake is largely responsible for the supercharger system's good manners. This setup equalizes vacuum between the top and bottom, allowing the compressor to free-wheel with hardly any parasitic losses at cruising speeds. Approximately 1/4 of a horsepower is lost to belt drive friction, according to Allen, and the blower will turn (on vacuum) without a belt.
With half the engine under...
With half the engine under the windshield, as current trend dictates, the Allen installation requires either a few helping hands, or the use of an impromptu lifting device, as pictured. Considering the 38 percent increase in horsepower that resulted (at 250 rpm lower than the stock power peak), a little sweat during installation seems well worth the effort. In that sense, tehre is a substitute for cubic inches.
Seen from above, the Allen...
Seen from above, the Allen unit doesn't look particularly interesting. That's because Magnuson managed to stuff all the important items underneath it. It's a perfect stealth setup, adn those who are unaware would not even suspect the supercharger's presence when they're peeking under the hood.
Viewed from the engine's perspective,...
Viewed from the engine's perspective, the new manifold holds the Eaton blower, which supplies a 5-psi boost, as well as the innovative bypass valve behind it, (lower left.)
Here is the heart of the air-to-liquid...
Here is the heart of the air-to-liquid intercooler setup. Shown are the intercooler water pump, coolant reservoir, heat exchanger, and on top, the included oil cooler heat exchanger.
This nearly-finished installation...
This nearly-finished installation clearly shows how well-disguised the Allen system is, and even more so with the accessories and hoses reinstalled. Few would suspect that the innocent-looking snout sticking out from below the manifold is the beginning of a system that improved torque by 26 percent.
Before being sold, each Allen...
Before being sold, each Allen system is tested for temperature, pressure, and noise. The gears are lubricated by synthetic oil, which should be checked every 50,000 miles. The average rebuild interval is about 105,000 miles, and this usually consists of replacing a few bearings and changing the oil, as the case and rotor are generally in good shape at this stage.