This is ATI ProCharger's complete Serpentine Race Kit with an F-1A centrifugal supercharger for '96-'04, Two-Valve Mustang GTs and Four-Valve Cobras (PN 1FX204-DISC w/F1-A Upgrade; $5,737). A six-rib blower pulley would normally be included with this package, but it has been omitted in our case since we're stepping up to an eight-rib configuration. With the exception of the head unit, the hardware in this system is similar to that of the P-1SC Stage II blower and intercooler we installed on our GT's bone-stock 4.6 in the Jan. '06 issue. Actually, the F-1A blower unit can bolt directly onto the same bracket as the P- and D-series superchargers.
While our P-1SC called for six ounces of lubricant, the F-1A only requires four ounces of ProCharger's lightweight oil. The F-1A's dual-bearing design allows its transmission to function similar to a two-speed and achieve a much higher rpm (estimated 70,000 rpm redline) than single-bearing blowers. This makes it crucial to the life and performance of the unit to maintain sufficient oil supply. We changed the engine oil (Royal Purple XPR 5W30) and added a new set of NGK TR-6 spark plugs (0.030 gap) prior to outfitting the 4.6 with this big-boost supercharger.
We bolted on the 4.25-inch blower pulley for our initial test. This wheel should net approximately 12-15 psi of boost and will be ideal for using the big supercharger for our street-car application. The smaller, 3.70-inch pulley will spin the F-1A much faster and create nearly 20 psi of boost. While we'll be fine using 91-octane fuel for the 4.25-inch, race gas is a must when you play with the kind of pressure the 3.70-inch can generate.
One of the major additions to our new Two-Valve program is this bolt-in, aluminum two-row radiator from Fluidyne (PN FHP20 97MU; $439; fits '97-'04), which B&D Racing's Brian Schapiro strongly recommends with almost all the supercharger installations the shop performs. Big heat is a result of big boost, and the fact that our 'Stang is driven in sometimes brutal SoCal temperatures and freeway traffic is all the more reason why having a good cooling system is important. The OEM fan is retained, and we added one bottle of Royal Purple's Purple Ice to the coolant/water mixture, ensuring the GT's mechanicals keep cool when the temperature climbs.
Our three-core, sheetmetal, race intercooler features taller plenums than the three-core version used with our P-1SC/stock 4.6 combination. This inter-cooler works better with the F-1A because of its ability to support more air volume. "Bigger is better when it comes to intercoolers, as long as it doesn't create a huge pressure drop," Dorian says. The intercooler and Fluidyne radiator will receive more than enough air through the lower opening and grille area of the bumper cover.
Dorian set up a dual surge-valve system instead of a single Pro-Flow valve to disperse bypassed air that can't enter the throttle body when the butterfly is shut. By going with two valves, we're decreasing velocity of the vented air, tempering the sound of its discharge. For a good idea of how an F-1A sounds at idle, just think about an F-14 fighter jet-in afterburner.