Second fuel pump question need help asap - Page 2 - 6SpeedOnline

#16

02-02-2012, 07:50 PM

Tim941NYC

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Location: Long island NY

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Quote:

Originally Posted by Tony@epl

Ok... just looking at the simple science of it for a second.

(power*bsfc)/ (# of injectors/ Target duty cycle run) = approx injector size

Solving for stock BSFC:
Stock power = 415
BSFC = X
# Of injectors = 6
Max DC stock under load = 80

(415 * X)/(6 /80) = 44lb

x=.61

Now a tuned car with 850hp and 60lb injectors:

(850* X)/(6/90%) = 60

Tuned power = 850
BSFC = X
# Of injectors = 6
Max DC stock under load = 90

x= .4479

The math doesnt add up... I don't understand how anyone could be picking up 35%+ efficiency especially when you consider that factory BSFC is based on a MUCH leaner AF ratio.

If this is possible... who ever figures it out would make way more money designing engines for OE applications then tuning cars

.

I could not agree more with you Tony but there is one thing not in your math. That is the crazy rail psi need to make a 60lbs injector provide the fuel needed to make the power claimed. Not saying its not making the power.

OP, I am not a fan of twin pumps but a pump has the greatest flow with no head psi. No secret there. So if the second pump is providing the head psi then the first pump will be a lift pump. Now with no head to pump against the pump will increase in liters per hour as a result of the second pump being the pressure pump.

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