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Discussion Starter #1
anyone aware of an automatic BAP. It seems to me that the KB BAP is 90% there. adding a sensor in the fuel rail and a tiny PID controller to a circuit board would be an easy step. then have one potentiometer to vary the setpoint.

any input????
 

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BYAHHHH!
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just wire it to full time
 

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Discussion Starter #3
is there any downside to that??? excessive wear or too much pressure when you don't need it?
 

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Fuel pressure is supposed to remain constant. A BAP doesn't increase fuel pressure but rather makes sure it doesn't drop off when your pump would normally be getting maxed out.

Straight from KB:

The installation of our Boost-A-Pump will actually increase pump life by reducing its
workload. BTW: the Boost-A-Pump only increases the voltage when required under boost
conditions. It is a passive system otherwise.

BOOST-A-PUMP THEORY EXPLAINED
 

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Discussion Starter #5
gotcha. thank you.
 

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The original BAP setups actually used a vacuum sensor. When they sensed stronger pressure at a given vacuum line there would be an increase in the voltage to the pump. Now they all ship with that dial thing so you set it yourself. Mine was one of the vacuum regulated ones and i was told by my tuner to ditch the vacuum sensor and just tie the wires together to make it run 100% all the time.
 

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^what he said.

Ive got a 20 amp with the vacuum sensor for $150 shipped if interested. only used it for about 6 months.
 

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Your fpdm. Controls your fuel pump volts. Like the person before stated wire it pre fpdm and it will do all the work
 

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Discussion Starter #9
found this article from Ford Racing. it appears as though Ford already does what i originally asked...
And if that's the case, how does the BAP bypass this?


The nominal injection pressure for most Ford EFI systems is 39.15 psi (270 kPa) “across the injector.” The term “across the injector” takes manifold pressure and fuel rail pressure into account, and is usually referred to as “delta pressure.” Ford Racing’s fuel injectors are always rated at 39.15 psi delta, so the fuel injector sizing discussions found below will assume a fuel pressure of at least 39.15 psi delta. There are some exceptions to the above-mentioned nominal injection pressure. In relatively recent years, emissions regulations have become so stringent that the government is now regulating the emissions output that gasoline vehicles are allowed to produce even when the engine is not running! This is referred to as “evaporative emissions” and results from unburned hydrocarbons (raw fuel) emitting into the atmosphere from the fuel tank, fuel lines, injector leakage, intake manifold, etc. when the engine is shut off. This is the fundamental purpose of the charcoal canister (and hydrocarbon trap in the air-box on many vehicles) and is also the reason that Ford switched to the Returnless Fuel Systems (RFS) found in production vehicles today. These systems have only a fuel supply line from the tank to the engine, with no return line. The primary reason for these systems is that evaporative emissions increase as the temperature of the fuel in the tank increases. On a conventional return system, the fuel is sent to the engine through the supply line, and the excess is returned (via the mechanical fuel pressure regulator) to the tank through the return line. Since the engine is hot, this process heats up the fuel and thus increases evaporative emissions. To combat this, the returnless fuel systems were invented. Currently, Ford uses 2 primary types of RFS which are called Electronic Returnless Fuel System (ERFS) and Mechanical Returnless Fuel System (MRFS). The latter is the simpler of the two systems and controls the fuel rail to a constant pressure via a regulator in the tank, which is typically set to around 60 psi. The powertrain control module (PCM) then calculates the pressure across the injector either by inferring or measuring manifold pressure and subtracting from what it knows is the rail pressure set-point. ERFS, on the other hand, has no mechanical regulator at all, but instead has a Fuel Rail Pressure Transducer (FRPT) mounted on the fuel rail that measures fuel rail pressure relative to manifold pressure and feeds that information back to the PCM. The PCM then controls the Fuel Pump Driver Module (FPDM) which in turn varies the voltage to the fuel pump (or pumps) in the tank to supply the correct pressure and flow rate to the injectors. Most of the time this pressure is maintained at 39.15 psi delta, but when the fuel temperature rises, this pressure can be boosted in order to delay the onset of boiling the fuel. Some vehicles also boost the pressure under some conditions in order to get away with using smaller flow-rate fuel injectors for various reasons beyond the scope of this tutorial. Both V6 and V8 Mustangs have used ERFS since the 1999 model year and continue to do so today. The purpose of going into all this detail is to convey the message that if you choose your fuel injectors based on a pressure of 39.15 psi delta (which is the pressure at which Ford Racing specifies the flow rate), the injectors will be correctly sized regardless of which fuel system you actually have, and also to show you that fuel pressure on ERFS vehicles can change based on a number of conditions.
 
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