Injectors
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08-13-2008, 11:22 PM
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#2
08-14-2008, 01:29 PM
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08-14-2008, 09:07 PM
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08-14-2008, 09:29 PM
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You already have 23.2lb injectors from the factory, I think you could easily find something else for the money that will help in the power department. Heres a little tool to help you calculate what you need for injector size.
HP(crank)/ # of cyl/ .80 (max duty cycle 80%)* BSFC = Injector size
BSFC for a N/A motor is: .45 - .50 (BSFC is Brake Specific Fuel Consumption)
BSFC for a F/I motor is : .55 - .60
So lets say you have 265hp.
265 / 8 / .80 * .50 = 20.7
So even at a slightly higher hp rating than factory you still have more injector than you need. It would take about 300 crank hp to exceed the factory injectors.
HP(crank)/ # of cyl/ .80 (max duty cycle 80%)* BSFC = Injector size
BSFC for a N/A motor is: .45 - .50 (BSFC is Brake Specific Fuel Consumption)
BSFC for a F/I motor is : .55 - .60
So lets say you have 265hp.
265 / 8 / .80 * .50 = 20.7
So even at a slightly higher hp rating than factory you still have more injector than you need. It would take about 300 crank hp to exceed the factory injectors.
#6
08-15-2008, 08:12 AM
begin quote:
"I read the following from the Q&A section of the April 2001 Mopar
Performance News:
Q(5) I'm working on a fuel-injected combination and my dyno program
shows I could benefit from more injector delivery. What can you tell me
about flow rates of the injectors in your catalog? Also, if you have
the factory injector rates would be very helpful.
A(5) You should step up the injectors in something like only 25 percent
increments. The production V-8 is 24 - the MPP package is 30! Remember
that you must change the computer if you change the injectors; at the
least, it must be reprogrammed with the new injector values. Injector
rates are not as easy as one might think, but they go something like
this:
Engine Years Flow rate in lb/hr
Neon ( All) 23.9
2.5 Magnum 91-95 17.4
2.5 Magnum 96-01 23.2
4.0 Jeep 91-95 21.4 (Equivalent to Lucas 5207013 )
4.0 Jeep 96-01 23.2 (Equivalent to Lucas 5208005 )
5.2 Magnum 92-95 18.2
5.2 Magnum 96-01 23.2
5.9 Magnum 93-95 24.5
5.9 Magnum 96-01 23.2 (Seimens/Chrysler P/N 53030778)
---end quote---
Note that about 1996,
when the engine PCM computers went to the OBD-II standard,
all the Dodge fuel injectors went to a 'common calibration' of 23.2 lb/hour.
There is another article about different makes of fuel injectors I
read at:
http://web.archive.org/web/200106101...ectioninfo.htm
If you have a modified 1996+ Magnum engine and you feel you need to 'bump up'
the fuel injectors just a bit, the model year 1993-1995 5.9V8 fuel injectors
are about 6% larger at 24.5 versus 23.2, and Neon injectors are 3% bigger.
There is seldom a need to go to larger fuel injectors on 3.9/5.2/5.9 Magnum engines with any mod short of a supercharger, but replacing the one or two cylinders that have a tendency to ping can have beneficial effects.
"I read the following from the Q&A section of the April 2001 Mopar
Performance News:
Q(5) I'm working on a fuel-injected combination and my dyno program
shows I could benefit from more injector delivery. What can you tell me
about flow rates of the injectors in your catalog? Also, if you have
the factory injector rates would be very helpful.
A(5) You should step up the injectors in something like only 25 percent
increments. The production V-8 is 24 - the MPP package is 30! Remember
that you must change the computer if you change the injectors; at the
least, it must be reprogrammed with the new injector values. Injector
rates are not as easy as one might think, but they go something like
this:
Engine Years Flow rate in lb/hr
Neon ( All) 23.9
2.5 Magnum 91-95 17.4
2.5 Magnum 96-01 23.2
4.0 Jeep 91-95 21.4 (Equivalent to Lucas 5207013 )
4.0 Jeep 96-01 23.2 (Equivalent to Lucas 5208005 )
5.2 Magnum 92-95 18.2
5.2 Magnum 96-01 23.2
5.9 Magnum 93-95 24.5
5.9 Magnum 96-01 23.2 (Seimens/Chrysler P/N 53030778)
---end quote---
Note that about 1996,
when the engine PCM computers went to the OBD-II standard,
all the Dodge fuel injectors went to a 'common calibration' of 23.2 lb/hour.
There is another article about different makes of fuel injectors I
read at:
http://web.archive.org/web/200106101...ectioninfo.htm
If you have a modified 1996+ Magnum engine and you feel you need to 'bump up'
the fuel injectors just a bit, the model year 1993-1995 5.9V8 fuel injectors
are about 6% larger at 24.5 versus 23.2, and Neon injectors are 3% bigger.
There is seldom a need to go to larger fuel injectors on 3.9/5.2/5.9 Magnum engines with any mod short of a supercharger, but replacing the one or two cylinders that have a tendency to ping can have beneficial effects.
