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Circle Racing Stockton, Ca. post July 7th update

We attended the July 7th race with about 30 winged FI sprint cars and several other carburetor fed racers and late models all competing in front of a couple thousand spectators; thanks to Dani Noceti and staff for a great evening; many couples and families with children all enjoying the competition; very safe and clean environment; the entire staff was friendly and all enjoying themselves; reasonable parking facilities; well equipped food services; the licorice was great; I really enjoyed those powerful circle racecars; final heat of 30 laps ran after 11:00 for cool and comfortable entertainment.

Most of the MFI cars were Kinsler or Engler fuel injection. Several crew chiefs said flat lining fuel pressures were maintained over 100 psi for the high speed bypass opening point. Most had the conventional fuel pump location behind the motor with a suction pickup from the rear mounted tank. I was impressed with the punch coming out of the turns. There was only a momentary let up approaching the turns, then back on the throttle around the turns. Stockton dirt track is a little over 1/3 mile. Full throttle most of the time. I was impressed with how orderly the drivers and push cars all worked together to coordinate the starting positions. Only a couple red flags for a flip. The safety staff was johnny-on-the-spot getting to car rotations or the occasional flip. The Stockton dirt track has a large flat run-off for the racecars so no outside guard rails to collide with. There were numerous high dollar semi rigs in the pits filled to the brim with competitors. I spoke with 28 of the crew chiefs all of whom were friendly and open about the various tune-ups.

previous lising:
Stockton 99 Speedway; July 3; tune & test
Stockton 99 Speedway; July 4; Ron Strmiska Memorial Late Models, Bombers, B4 Cylinder, Mini Cups, & Fireworks
Stockton Dirt Track; July 7; Salute to Leroy Van Conett, Elk Grove Ford 360 Sprint Car Challenge (racing mechanical fuel injection), Hunt Magneto Sprint, & B-Modifieds

Let us know if you will be racing.

High HP from Rons MFI Throttle Bodies

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.

Top Notch Fuel Injection Tuning

Due to popular demand, we can now provide our ProCalc fuel injection jetting calculator already set up to run your fuel injection combination. This special service includes an extensive evaluation of your fuel injection setup and a custom fuel injection manual all about your engine. We have already done different fuel injection configurations, fuels, and various racing classes. We also did the service in different countries. It is strongly air/fuel ratio based. A few records & championships resulted. Info at: https://airdensityonline.com/protune/