I'm not even quite sure where individuals got the 21# rating, unless it was from a site that sells Bosch injectors, and they regularly have the information incorrect on many of them.
The flow rating, which is given by Ford at a fuel pressure of 44 psi (or somewhere around that), was changed based on the change from return style systems to returnless.
Actually, the injector calibration values are created by Ford at approx. 39.15 psi (varies in the 39.x range). They are rated by the manufacturer at 3-bar, which is 43.5 psi. GM rates their injectors at 4-bar (58 psi).
Also, Ford has kept 39.x psi as their used fuel pressure since they've been using fuel injection (all the way back to the SVO and '86+ Mustangs). On the Mustang, Ford switched from return-style to returnless beginning with the '99 model year.
In 2002 the electrical connection changed when Bosch switched from the EV-1 style to the EV-6. Other than electrically, they retain the same capacity and spray cone pattern.
Actually, Ford used the Jetronic/Minitimer connector on ALL EFI Mustang 5.0 and 4.6 2V engines from '86 to '04, and '96-'98 4V. The '99 & '01 Cobra, '03-'04 Mach 1, and '03-'04 Cobra, and ALL '05+ Mustangs, use USCAR connectors. All Lightnings use Jetronic/Minitimer connectors.
To note, many people confuse the "injector body" call tag (EV1, EV6, EV14) with the injector connector. Some new style bodied injectors have old style connectors, and vice versa. See here:
PART NUMBER (SETS OF 8) FLOW RATE BODY STYLE IMPEDANCE LENGTH CONNECTOR
M-9593-C302* 19 lbs./hr. EV1 11-18 ohms L Jetronic/Minitimer
M-9593-LU24* 24 lbs./hr. EV6 11-18 ohms L USCAR
M-9593-AA302* 24 lbs./hr. EV6 11-18 ohms L Jetronic/Minitimer
M-9593-BB302* 30 lbs./hr. EV6 11-18 ohms L Jetronic/Minitimer
M-9593-MU32* 32 lbs./hr. EV14 11-12 ohms M USCAR
M-9593-LU34* 34 lbs./hr. EV6 11-12 ohms L USCAR
M-9593-M39* 39 lbs./hr. EV6 11-18 ohms L USCAR
M-9593-F302* 42 lbs./hr. EV1 11-18 ohms L Jetronic/Minitimer
M-9593-G302* 47 lbs./hr. EV14 11-18 ohms M USCAR
M-9593-LU60* 60 lbs./hr. EV6 11-12 ohms L USCAR
M-9593-LU80* 80 lbs./hr. EV6 11-12 ohms L USCAR
Furthermore, The "pink" 19# injector still uses the Jetronic/Minitimer connector, just as the orange 19# injector did. The injectors are identical, save for part #. See here:
As others have pointed out, the flow rating is completely contingent upon fuel pressure. However it is not linear due to physics , you cannot double fuel pressure and expect a 21# injector to behave like a 42# injector. Yes, fuel will increase but it will not come close to doubling.
That is 100% spot on. The Bernoulli equation is used when resizing injectors for varying flow rates (the flow rate increases with the square root of the pressure ratio). HOWEVER, this also changes the injector dynamics of the injector operation. Instead of attemping to explain it out, I suggest one take the time to read the below "Fuel Injector Article" by my friend Greg Banish (Calibrated Success):
I've actually heard this same thing about the 39lb/hr injectors used on the '03-'04 Cobra's and the 42lb/hr injectors used on the '99-04 Lightning. Although they're designated different sizes, they actually have the same flow rates as one and other. Anyone know for certain?
Take the injector "AHISL" ("high" injector slope) and multiply it by 3600 to get #/hr. So in the case of the Lightning, 0.011947 * 3600 = 43.0092 #/hr, and for the Cobra, 0.011133 * 3600 = 40.0788 #/hr. Now here is where it gets odd - Ford production uses different values than that on the Lightning and Cobra. On the Lightning they use 0.011300 * 3600 = 40.6803 #/hr, and on the Cobra they use 0.011133 * 3600 = 40.0794 #/hr. Personally, I'd trust Ford production data more closely. With all that being said, the similarities between those two injectors stop cold there, as ALL the other calibration data is drastically different between them. Therefore, you could NOT use Cobra injector values on a Lightning, and vice versa, or the vehicle would run like complete crap.
I'm not even quite sure where individuals got the 21# rating, unless it was from a site that sells Bosch injectors, and they regularly have the information incorrect on many of them.
Actually, the injector calibration values are created by Ford at approx. 39.15 psi (varies in the 39.x range). They are rated by the manufacturer at 3-bar, which is 43.5 psi. GM rates their injectors at 4-bar (58 psi).
Also, Ford has kept 39.x psi as their used fuel pressure since they've been using fuel injection (all the way back to the SVO and '86+ Mustangs). On the Mustang, Ford switched from return-style to returnless beginning with the '99 model year.
Actually, Ford used the Jetronic/Minitimer connector on ALL EFI Mustang 5.0 and 4.6 2V engines from '86 to '04, and '96-'98 4V. The '99 & '01 Cobra, '03-'04 Mach 1, and '03-'04 Cobra, and ALL '05+ Mustangs, use USCAR connectors. All Lightnings use Jetronic/Minitimer connectors.
To note, many people confuse the "injector body" call tag (EV1, EV6, EV14) with the injector connector. Some new style bodied injectors have old style connectors, and vice versa. See here:
Furthermore, The "pink" 19# injector still uses the Jetronic/Minitimer connector, just as the orange 19# injector did. The injectors are identical, save for part #. See here:
That is 100% spot on. The Bernoulli equation is used when resizing injectors for varying flow rates (the flow rate increases with the square root of the pressure ratio). HOWEVER, this also changes the injector dynamics of the injector operation. Instead of attemping to explain it out, I suggest one take the time to read the below "Fuel Injector Article" by my friend Greg Banish (Calibrated Success):
Take the injector "AHISL" ("high" injector slope) and multiply it by 3600 to get #/hr. So in the case of the Lightning, 0.011947 * 3600 = 43.0092 #/hr, and for the Cobra, 0.011133 * 3600 = 40.0788 #/hr. Now here is where it gets odd - Ford production uses different values than that on the Lightning and Cobra. On the Lightning they use 0.011300 * 3600 = 40.6803 #/hr, and on the Cobra they use 0.011133 * 3600 = 40.0794 #/hr. Personally, I'd trust Ford production data more closely. With all that being said, the similarities between those two injectors stop cold there, as ALL the other calibration data is drastically different between them. Therefore, you could NOT use Cobra injector values on a Lightning, and vice versa, or the vehicle would run like complete crap.
Some 24# are grey. The mach 1s that I have are grey and I have seen crown vic HPPs with grey 24#. They are EV6 style with EV1 connectors, the Machs are EV6 all the way.
1: Those are NOT 52# injectors. They are more like 47#.
2: Yes, they will work, but you will need Jetronic/Minitimer to USCAR connector adapters, and you'll need to modify your fuel rail attachments so that they will still bolt up to your intake (or make some sort of spacer).
3: Also, you will need to input the *exact* injector calibration data into your tune. If you don't, then your vehicle will NEVER run right. Here's the proper calibration data for them:
Some 24# are grey. The mach 1s that I have are grey and I have seen crown vic HPPs with grey 24#. They are EV6 style with EV1 connectors, the Machs are EV6 all the way.
Again, there is not any such thing as EV1 or EV6 "connectors". What you're calling "connectors" is actually the body design (EV1, EV6, EV14). On Fords, connectors are either USCAR (new style) or Jetronic/Minitimer (old style). Some new style bodied injectors (EV6 and EV14) have old style connectors.
Chris, I could be wrong, but those should be the exact same injectors as in the '05+ Mustang 3V. In looking at the data on them from an '04 Navigator calibration, they show to be a 24# injector.