This Quick Fuel technology...
This Quick Fuel technology (QFT) blow-through supercharged carburetor features many modifications compared to a standard performance carburetor. These include full-throttle shafts with Teflon bearings. Next are large-capacity annular boosters. These boosters are modified with 13 holes each, so that a large amount of fuel feeds each venturi and increases signal strength. The carb is also modified to supply more fuel without resorting to huge jets.
This pressure regulator from...
This pressure regulator from QFT (PN 30-1803) is boost-referenced to the carburetor box so that as boost increases, an appropriate pressure of fuel is allowed into the fuel system. This is required to allow the carburetor to operate in a pressure box.
The boost from the centrifugal...
The boost from the centrifugal supercharger on this engine transverses through a long pipe and into the top of the engine, where it makes a bend through what is called a hat. This system is generally best for full-race or fuel-injected operations. On carbureted systems, the high speed of the incoming boost often collects on the walls of the hat as the air negotiates the turn into the engine. This may cause uneven fuel distribution.
For long engine life the blower and applied boost should be matched to the quality of components inside the engine. Engines fitted with stock cast pistons, cast crankshaft, two-bolt main caps, and a small camshaft should run very low boost pressure (5 psi maximum). This is because higher boost levels can cause detonation and engine failure. If the fuel system, the ignition system, and the short-block are built with quality parts, 8-10 psi will work fine, depending on blower design and efficiency. Late-model computer-controlled ignition systems, automatic detonation retard, and EFI may permit running even higher compression ratios and boost pressures.
For engines run with boost levels from 6 to 10 psi
* Forged pistons
* Steel crankshaft
* Four-bolt main caps
* Steel harmonic damper
* Stainless steel valves
* Three-angle valve job
* More aggressive (blower-designed)camshaft
* Roller rockers
* High-flow cylinder heads
* Steel rods w/high-performance rod bolts
* Chrome-moly pushrods
* Strong ignition
* Upgraded cooling system
* Headers and free-flowing exhaust system
For maximum boost and horsepower applications (11 psi or more)
* High-quality forged or billet crankshaft
* Four-bolt main caps w/quality bolts or studs
* Steel harmonic balancer or crank hub
* High-quality steel rods (H- or I-beam)
* Forged blower pistons
* Severe-duty stainless steel valves
* Solid or roller cam designed for high boost
* Roller rockers
* High-output ignition-management system or magneto
* Blueprinted carburetors or fuel injection
* High-octane race fuel (112-plus rating)
* Minimum of a 3-inch-diameter dual exhaust with free-flowing street/race mufflers and large-tube headers.