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injdata-pressure [2011/12/13 15:28]
twdorris
injdata-pressure [2012/02/08 06:45]
twdorris
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 ====== Injector Data - Base pressure ====== ====== Injector Data - Base pressure ======
 Fuel flow rate through an injector is affected by a number of different things. ​ This page focuses on the effects of base fuel pressure and its influence on injector deadtime. Fuel flow rate through an injector is affected by a number of different things. ​ This page focuses on the effects of base fuel pressure and its influence on injector deadtime.
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 ===== Overview ===== ===== Overview =====
-Flow rate through an injector is substantially influenced by the pressure differential across the injector. ​ If we assume that a given injector has been rated at the industry standard of 3-bar (43.5 psi), then the well-known formula for calculating the effect of changing fuel pressure is below.+Flow rate through an injector is substantially influenced by the pressure differential across the injector. ​ If we assume that a given injector has been rated at the industry standard of 3-bar (43.5 psi), then the well-known formula for calculating the basic fuel flow effect of changing fuel pressure is below.
  
   NewFlowRate = RatedFlowRate * squareroot(NewBasePressure / 43.5)   NewFlowRate = RatedFlowRate * squareroot(NewBasePressure / 43.5)
  
 But fuel pressure also affects how quickly the injector can open and close. ​ Higher pressure differential (base pressure) increases the amount of force the injector internals have to overcome to start flowing. ​ This increases the "​deadtime"​ of the injector and needs to be taken into account. But fuel pressure also affects how quickly the injector can open and close. ​ Higher pressure differential (base pressure) increases the amount of force the injector internals have to overcome to start flowing. ​ This increases the "​deadtime"​ of the injector and needs to be taken into account.
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 ===== Data ===== ===== Data =====
-To illustrate this affect, we took a set of FIC BM1450s and ran them at varying fuel pressures from 35psi up to 60psi in 5psi increments. ​ The results are shown below.+To illustrate this effect, we took a set of FIC BM1450s and ran them at varying fuel pressures from 35psi up to 60psi in 5psi increments. ​ The results are shown below.
  
 |{{pressure-effects.png?​300|Fuel pressure effect on deadtime}}| |{{pressure-effects.png?​300|Fuel pressure effect on deadtime}}|
injdata-pressure.txt ยท Last modified: 2024/03/15 11:16 (external edit)