Injector sizing and boost-referencing the fuel injected engine for centrifugal supercharging.

Injector sizing and boost-referencing the fuel injected engine for centrifugal supercharging.

By Sam Logan: If larger injectors are installed—that is, injectors with a greater flow rate—an engine tuning shop is usually required to re-tune the map—the fuel curve—to achieve the correct air-fuel ratio. To acquire a safer tune in a supercharged engine, where cylinder heat increases with boost, tuning shops will often adjust the air-fuel ratio to 12.0:1 at full throttle as opposed to around 12.8:1 on a naturally aspirated engine. In cruising conditions, air-fuel ratios will remain at 14.7:1 The size of the injector limits the amount of horsepower generated, and calculations are used to decide the appropriate injector for desired maximum rpm and horsepower. They are calculated in pounds-per-hour of fuel dispersed. For example, 25lbs-per-hr is sufficient to support 350hp; 45lbs-per-hr is sufficient for 500hp and so on. Here is a table with more particulars: FLOW RATE DEFINITION, CALCULATING HORSEPOWER RANGE. Horsepower is measured at crankshaft. Injector Flow RateNaturally Aspirated EngineEngine w/ Power Adder19 lbs./hr.225-290 hp185-240 hp24 lbs./hr.280-360 hp240-300 hp30 lbs./hr.350-450 hp300-375 hp36 lbs./hr.425-540 hp350-450 hp42 lbs./hr.500-625 hp410-525 hp46 lbs./hr.540-690 hp450-575 hp52 lbs./hr.610-775 hp510-650 hp60 lbs./hr710-900 hp590-750 hp Supporting a supercharged engine with sufficient fuel is a moving target—there are numerous factors to consider, even the model year of the same engine and vehicle brand. The route is determined by the amount of supercharge boost and the capacity of the fuel pump along with the flow capability of the fuel injectors. Avoid confusion: Injector flow capability is measured in lbs/hr—not psi. Supercharging with boost referencing or booster pump or larger fuel injectors: The reason for introducing more fuel pressure is as follows: for every pound per square inch...
Superchargers and carbureted fuel system upgrades.

Superchargers and carbureted fuel system upgrades.

By V. Moore: Idle and cruise conditions don’t alter fuel consumption appreciably, but supercharge boost conditions do. Therefore, it’s sensible and probably necessary to increase fuel pressure relative to boost pressure, upgrading to a larger capacity electric fuel pump and bypass fuel pressure regulator. Bypass fuel systems using a return-style regulator are the most efficient kind. They control fuel pressure constantly to the engine and return the surplus to the tank. The system is more responsive to fluctuating fuel demands, and as the fuel circulates from hot engine bays, it averts power losses and stalling from vapor locks. The advantage of the in-tank fuel pump is durability because it is submerged in cool fuel. Also, it is much easier to push fuel than to pull fuel. The disadvantage of the in-tank fuel pump, especially with high performance vehicles, is that if the fuel level in the tank is low, the fuel becomes warm because the pump is warm and the desired cooling effect is lost. Best practice is not to allow fuel level to fall below half tank or avoid driving with low fuel. The formula for upgrading a fuel system. The formula for determining a fuel system’s capability is based on a vehicle’s horsepower output. Typically, an engine consumes ½lb of fuel per horsepower per hour. Therefore, feeding 500hp requires 250lbs of fuel per hour. As 1 gallon of fuel weighs approximately 7lbs, simply divide 250 by 7 to find the answer, which is 35.7 gallons. Thus, a fuel pump is required that generates a minimum of 40 gallons (150 liters) per hour to feed the engine at...
Boost referencing the blow-through carburetor (4150-style) and fuel pressure regulator

Boost referencing the blow-through carburetor (4150-style) and fuel pressure regulator

By V. Moore: Conventional carburetors operate at prevailing barometric pressures, from oxygen-rich sea level to oxygen-lean Denver, a mile high in Colorado. Blow-through carburetors, which work in conjunction with centrifugal superchargers and turbochargers, operate with boosted pressure. It’s a contrasting concept that accelerates the induction process. It impels higher velocity fuel flow through the main jets and robustly emulsifies the air-fuel mixture in the metering passageways, as it makes its way to the carburetor’s boost venturii. The boost venturii are carefully positioned in a choked area, an area with a reduced cross-section to increase the air speed. Increased air speed lowers the air pressure at the small discharge orifice in the booster, extracting the air-fuel mixture into the air stream on its journey to the cylinders. When boost pressure enters the fuel bowls, via the two vent tubes, its force lowers the fuel levels and quickly becomes so potent with increasing engine speed that the needle-and-seat valves cannot keep pace with demand. To keep the carburetor flowing relative to boost, the float bowls must be pressurized. As boost pressure increases, fuel flowing through the metering systems increase proportionally. Further, as the float bowls are pressurized, the fuel pump must overcome that boost pressure (as opposed to the naturally aspirated condition of pumping fuel through the needle-and-seats into float bowls that are vented to atmosphere). If 7psi of fuel pressure were employed to a normally aspirated engine and 7psi of boost applied to the float bowls, the pressure in the float bowls and the pressure from the fuel pump would be equal, causing zero fuel to flow through the needle-and-seats. So,...
Bradenton, Florida: Inaugural TorqStorm Superchargers 2020 True Street event

Bradenton, Florida: Inaugural TorqStorm Superchargers 2020 True Street event

By Sam Logan: Naturally, there’s a desire within the TorqStorm operation to introduce enthusiasts to their billet supercharger. But also there’s a keenness to acquaint them with the racing scene, especially those with no former competition experience. So 2020 marks the beginning of a new era for TorqStorm, an initiative with the NMCA to sponsor their well-established True Street class. True Street rules call for the entrants to take a 30-mile cruise followed by three successive drag strip passes. As a special feature for this event, they were led by Drag Week winner Tom Bailey and his Camaro with YouTube celebrity Cleetus McFarland occupying the passenger’s seat.     The race results were as follows: Mike French triumphed, motoring to an overall win with an 8.77sec average, while Jason Rollins claimed runner-up, finishing with an 8.96 average. Willard Howard was the tour de force in the 9-second category, Jeff Smith the 10-second, and TorqStorm’s own Jeff Neibarger was the 11-second winner. Grant Martin won the 12-second category, with Jose Vera and Jimmy Hodges winning the 13-second and 14-second categories respectively.  Branden Arila took the spoils in the 15-second...
How to change the oil on a TorqStorm supercharger.

How to change the oil on a TorqStorm supercharger.

Since TorqStorm’s beginning, about ten years ago, inquirers have written on virtually every aspect of forced induction. Oil-changing procedures is a popular topic. Required at 10,000-mile intervals or once a year, whichever comes first, here are the four steps with pictures and captions to clarify. Step 1 Remove your supercharger from your car and flip it over onto backside to access drain plug. Step 2 Remove drain plug with 1/4in Allen wrench and drain oil. Step 3 Through the drain hole, pour 6fl oz of TorqStorm-specific oil. Step 4 Replace drain plug and tighten to 15lbs- ft of torque.   An oil change must be performed every 10,000 miles or once a year, whichever comes first. Failure to do so will void the warranty. Oil can be purchased directly from TorqStorm for $6: Part# ARP-OIL-GT46   TorqStorm SuperchargersTorqStorm.comTelephone (616) 706-5580 or visit www.TorqStorm.com or e-mail the knowledgeable Chris Beardsley...