Power FC Can I wire 6 injectors to power fc?
05-13-10, 01:53 PM
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Can I wire 6 injectors to power fc?
can anybody tell me if it's possible to wire 6 injectors to power fc,and if it is posible how to do it.Your help will be appreciated.
05-13-10, 06:55 PM
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It is posible but if the impedance is too low, it could fry the PFC injector drivers.
Read below.
************************************************** *******
The PFC And Secondary Low Impedance Injectors
There have been discussions on the big forum on how much power the PFC injector drivers can safely handle. Some say the low impedance Bosch injectors don't need resistors. Some say they do; 3 or 5 or 10 ohms. I was reading pages 80 and 81 of the Datalogit manual. It states that the PFC injector driver's IC contains 4 FETS (field-affect transistors). Each has an impedance of .25 ohms, and that the IC has a total power dissipation safe level of 3 watts. If power is not accumulative, then it will be .75 watts per driver/FET.
Let's do some calculations. I will use a voltage of 14.3 VDC as that is the highest I have seen on any FD. The stock injectors are listed as 13.8 ohms. My Bosch 1600/1680 with the light gray top are 5.1 ohms.
Stock injectors first:
(14.3 / 13.8) * 4 * .25 = 1.04 watts. 1.04 / 4 = .26 The total wattage of 1.04 is way less than 3 watts, and the individual wattage of .26 is way less than .75.
Stock leading and Bosch 1600 secondary with 3 ohm resistors:
(14.3 / 13.8) * 2 * .25 = .52 watts
(14.3 / 8.1) * 2 * .25 = .88 watts
Total wattage = 1.4 watts. Less than 1/2 of the 3 watt maximum.
Secondary individual wattage = .44 is less than the individual max of .75 watts. We are safe by both total and individual wattage.
If we do not use the resistors:
(14.3 / 13.8) * 2 * .25 = .52 watts
(14.3 / 5.1) * 2 * .25 = 1.40 watts
The 1.92 watts total is safely less than 3 watts. The .7 watts per secondary is close to the max of .75. I would not use this combination as the individual wattage is too close unless it can be verified that total wattage is the main factor.
BUT; if we use 1 ohm resistors we have 1.69 total or .59 per individual.
1.69 total is less than 3 and .59 is less than .75.
2 or 1 ohms should be safe and give better response than 3 ohms.
who wants to experiment? Using the FJO driver for the secondary solves the PFC load problem and maximizes secondary injector fuel delivery.
Read below.
************************************************** *******
The PFC And Secondary Low Impedance Injectors
There have been discussions on the big forum on how much power the PFC injector drivers can safely handle. Some say the low impedance Bosch injectors don't need resistors. Some say they do; 3 or 5 or 10 ohms. I was reading pages 80 and 81 of the Datalogit manual. It states that the PFC injector driver's IC contains 4 FETS (field-affect transistors). Each has an impedance of .25 ohms, and that the IC has a total power dissipation safe level of 3 watts. If power is not accumulative, then it will be .75 watts per driver/FET.
Let's do some calculations. I will use a voltage of 14.3 VDC as that is the highest I have seen on any FD. The stock injectors are listed as 13.8 ohms. My Bosch 1600/1680 with the light gray top are 5.1 ohms.
Stock injectors first:
(14.3 / 13.8) * 4 * .25 = 1.04 watts. 1.04 / 4 = .26 The total wattage of 1.04 is way less than 3 watts, and the individual wattage of .26 is way less than .75.
Stock leading and Bosch 1600 secondary with 3 ohm resistors:
(14.3 / 13.8) * 2 * .25 = .52 watts
(14.3 / 8.1) * 2 * .25 = .88 watts
Total wattage = 1.4 watts. Less than 1/2 of the 3 watt maximum.
Secondary individual wattage = .44 is less than the individual max of .75 watts. We are safe by both total and individual wattage.
If we do not use the resistors:
(14.3 / 13.8) * 2 * .25 = .52 watts
(14.3 / 5.1) * 2 * .25 = 1.40 watts
The 1.92 watts total is safely less than 3 watts. The .7 watts per secondary is close to the max of .75. I would not use this combination as the individual wattage is too close unless it can be verified that total wattage is the main factor.
BUT; if we use 1 ohm resistors we have 1.69 total or .59 per individual.
1.69 total is less than 3 and .59 is less than .75.
2 or 1 ohms should be safe and give better response than 3 ohms.
who wants to experiment? Using the FJO driver for the secondary solves the PFC load problem and maximizes secondary injector fuel delivery.
05-13-10, 08:17 PM
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i have it the fjo with 4 1600 injectors.I'm running e 85 and I'm making over 600hp.I wanted to know because I'm looking to go over 700hp and I would definetely get there with 6 injectors.Thanks for the info
05-14-10, 08:52 PM
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If the PFC is driving the FJO only and not driving any secondary injectors directly, then you can add two to the PFC output. Think about what the articel above explains.
12-10-10, 01:42 AM
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I have an Xcessive/GZ manifold and want to run 6 injectors as well. What about the newer Bosch injectors that don't need resistors. How would one add 2 more injectors to the mix? I was thinking either stock primaries or Bosch 740's and 4 Bosch 1000's secondaries(ev14's for both).
Thanks!
Thanks!
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