Rons Fuel Injection provided MFI throttle body flow data so that we could analyze the power potential of these low cost, simple fuel injection systems. Racing engine sizes and horsepower potentials were determined at these flow cfm numbers for 100% air density, and are included.
Rons FI MFI Toilets
3-3/4″ = 1240cfm: can feed 595 cubic inch engine @ 8,000 RPM with 1,071 HP at 1.8 HP / ci
4″ = 1435cfm: can feeds 689 cubic engine @ 8,000 RPM with 1,240 HP at 1.8 HP / ci
4.1″ = 1800cfm: can feeds 864 cubic inch engine @ 8,000 RPM with 1,555 HP at 1.8 HP / ci
Rons FI MFI Terminators
1-7/8″ = 1150cfm: can feed 552 cubic inch engine @ 8,000 RPM with 993 HP at 1.8 HP / ci
2-1/8″ = 1475cfm: can feed 708 cubic inch engine @ 8,000 RPM with 1,274 HP at 1.8 HP / ci
2-1/2″ = 2100cfm: can feed 1,008 cubic inch engine @ 8,000 RPM with 1,814 HP at 1.8 HP / ci
Rons FI MFI T2’s
2-1/8″ = 1880cfm: can feed 902 cubic inch engine @ 8,000 with 1,624 HP at 1.8 HP / ci
2.400″ = 2300cfm: can feed 1,008 cubic inch engine @ 8,000 with 1,814 HP at 1.8 HP / ci.
The engine sizes that can be supported by these various throttle body assemblies are quite high. The horsepower potentials are reasonable and also quite high from these very simple fuel systems. The beauty of mechanical fuel injection is that smaller engines can also be fed by these throttle bodies without bogging. Fuel injection pumps fuel into each intake port at high pressure when the throttle is slammed open. Further more, air is not interrupted by venturies or boosters. Stand back!
Thanks to Alan Greszler, Rons Fuel Injection.
Note: The engine size and HP additions were determined using the following math:
step (1) cfm x 12 x 12 x 12 = cubic inches per minute
step (2) cubic inches per minute / 8,000 RPM = cubic inches per revolution
step (3) cubic inches per revolution x 2 = cubic inches of 4 cycle engine (normally aspirated)
step (4) cubic inches of 4 cycle engine / 0.9 = adjusted cubic inches @ 90% VE
step (5) adjusted cubic inches at 90% VE x 1.8 = horsepower assuming 1.8 HP / cubic inch.