What HP Can Your Fuel System
Support? |
BSFC:
(input) |
HP*lb/hr |
This is your Brake Specific Fuel
Consumption. 0.62 is an empirically supported estimate for modified,
stock-turbo 13B-REW engines. See this page for some
additional information. |
Fuel
Pressure:
(input) |
psi |
This is the effective fuel pressure,
which is your fuel rail/gauge pressure minus the manifold (boost)
pressure. |
Fuel
Injectors:
(input) |
| Bank |
# |
cc/min |
|
lbs/hr |
| 1 |
|
|
or |
|
| 2 |
|
|
or |
|
| 3 |
|
|
or |
| |
How many injectors do you have, and
how much fuel do they flow at the standard 43.5 psi pressure? Enter
values in cc/min or lbs/hr. |
Max
Duty Cycle:
(input) |
% |
This is the maximum duty cycle that
the injectors will experience. The stock 93-95 RX-7 ECU tops out
around 63%. The recommended maximum value for programmable engine
management systems is 80%-85%. Above that, the injectors might stay
open, which gives up tuning control. |
Drivetrain Losses:
(input) |
% |
This is an approximation of the power
lost in the transmission, differential, etc. I am not sure what
values are appropriate for FWD or AWD cars. |
Flywheel HP:
(output) |
HP |
With the above components, your fuel
system should be capable of providing enough fuel for this amount of
flywheel HP. This is comparable to manufacturers' HP ratings. |
Wheel
HP:
(output) |
WHP |
With the above components, your fuel
system should be able to supply enough fuel for this amount of HP at
the wheels. This is the power that is measured on a chassis
dynamometer. |
Specify These Additional Parameters to
Calculate Fuel Pump Requirements: |
Boost
Pressure:
(input) |
psi |
If your car is a turbo, how much
boost are you running? For normally-aspirated cars, enter
zero. |
Fuel
System Pressure Drop:
(input) |
psi |
A lot of the fuel pressure generated
by the pump can be lost in the restrictive plumbing of the fuel
system. This value affects the pressure your fuel pump will be
required to supply. See this
page for some interesting test data. |
Fuel
Pump Requirements:
(output) |
You need a pump that will flow:
| gal/hr |
|
| L/hr |
at psi |
| lbs/hr |
| |
Based on the parameters given above,
you will need a fuel pump that meets these requirements. It is a
good idea to give yourself a little safety margin over and above
this requirement. |