Saturated vs Peak and Hold
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Saturated vs Peak and Hold
I did a search for injectors and didnt find a clear answer. Simply put - what is the difference between the two types of Injectors and which one needs a resistor box and why? Is one kind better than the other? What kind do Honda's use? How does OBD1/2 affect injector type? thx
Joined: Aug 2002
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From: AZ, USA
Re: Saturated vs Peak and Hold (Muckman)
http://rceng.com/prices.htm
Here's a website that can help you out.
Generally Saturated injectors run at higher ohms of resistance and peak and hold run at lower ohms of resistance.
I believe on most obd2 honda's, your gonna need a resistor box if your going to use peak and hold injectors. I know for a 99 Si I you would need it setup this way. You won't need the resistor box if you get saturated injectors.
Doug from hondata says that saturated injectors generally have better throttle response on obd2 vehicles(dont ask me, I don't know why).
Nowadays you can get saturated injectors in almost any size. I know that nippon denso makes 850cc saturated ones.
Here's a website that can help you out.
Generally Saturated injectors run at higher ohms of resistance and peak and hold run at lower ohms of resistance.
I believe on most obd2 honda's, your gonna need a resistor box if your going to use peak and hold injectors. I know for a 99 Si I you would need it setup this way. You won't need the resistor box if you get saturated injectors.
Doug from hondata says that saturated injectors generally have better throttle response on obd2 vehicles(dont ask me, I don't know why).
Nowadays you can get saturated injectors in almost any size. I know that nippon denso makes 850cc saturated ones.
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Joined: Sep 2002
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From: Colorado Springs, Colorado, USA
Re: Saturated vs Peak and Hold (LiLOtaku)
Courtesy of SA from the AEM EMS Board.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">Some of you may be wondering what the difference is between high and low impedance injectors. High impedance injectors are used with Saturated Drivers. Low impedance injectors are used with Peak and Hold Drivers or with Saturated drivers when used in conjuction with a ballast resistor (resistor box). The following, taken from SAE J1832 Nov 1989 - Gasoline Fuel Injector, defines each method and also lists the advantages and disadvantages to each.
SA
Injector Driver—An electronic circuit that supplies voltage pulses to an electromagnetic fuel injector for a precise increment of time and at a given repetition rate. The accuracy of these pulses and their repetition is
normally ±0.001 ms. The peak-hold driver and the saturated driver are most commonly used by the industry for vehicle applications.
PEAK-HOLD DRIVER—A driver that uses two levels of current to operate the injector. The driver circuit applies battery voltage to the injector until a predetermined current level is reached. The current is then reduced and held at a lower level for the duration of the PW. This type of driver is normally used with injectors having low resistance coils (typically around 2 ohm). The accuracy of the driver peak current level (Ip) and the hold current level (Ih) is held to ±0.50%.
Advantages—The high peak current minimizes OT response and the low hold current minimizes CT response. This method of control results in an increased linear range of injector operation.
Disadvantages—Heat is primarily dissipated at the driver. Circuitry is more complex than that of the saturated driver.
SATURATED DRIVER—A power transistor driver that turns fully on for the entire duration of the injector PW. This type of driver is used with injectors having high resistance coils (typically 12 to 16 ohm) or with
injectors having low resistance coils in combination with a ballast resistor.
Advantages—Heat is primarily dissipated through the injector or ballast resistor and not at the driver circuit. Circuitry is simplified compared to the peak-hold driver.
Disadvantages—The inherently slower dynamic response of this system decreases the injector’s usable flow range. The Q of an injector used with this type of circuit is more duty cycle sensitive due to heat dissipation considerations. This driver’s inductive suppression, which may be resistance, capacitance or zener, significantly affects the injector’s Qd rates due to variations in the circuit’s current decay rate. This decay results in a change of the injector’s closing time.</TD></TR></TABLE>
Bottoz
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">Some of you may be wondering what the difference is between high and low impedance injectors. High impedance injectors are used with Saturated Drivers. Low impedance injectors are used with Peak and Hold Drivers or with Saturated drivers when used in conjuction with a ballast resistor (resistor box). The following, taken from SAE J1832 Nov 1989 - Gasoline Fuel Injector, defines each method and also lists the advantages and disadvantages to each.
SA
Injector Driver—An electronic circuit that supplies voltage pulses to an electromagnetic fuel injector for a precise increment of time and at a given repetition rate. The accuracy of these pulses and their repetition is
normally ±0.001 ms. The peak-hold driver and the saturated driver are most commonly used by the industry for vehicle applications.
PEAK-HOLD DRIVER—A driver that uses two levels of current to operate the injector. The driver circuit applies battery voltage to the injector until a predetermined current level is reached. The current is then reduced and held at a lower level for the duration of the PW. This type of driver is normally used with injectors having low resistance coils (typically around 2 ohm). The accuracy of the driver peak current level (Ip) and the hold current level (Ih) is held to ±0.50%.
Advantages—The high peak current minimizes OT response and the low hold current minimizes CT response. This method of control results in an increased linear range of injector operation.
Disadvantages—Heat is primarily dissipated at the driver. Circuitry is more complex than that of the saturated driver.
SATURATED DRIVER—A power transistor driver that turns fully on for the entire duration of the injector PW. This type of driver is used with injectors having high resistance coils (typically 12 to 16 ohm) or with
injectors having low resistance coils in combination with a ballast resistor.
Advantages—Heat is primarily dissipated through the injector or ballast resistor and not at the driver circuit. Circuitry is simplified compared to the peak-hold driver.
Disadvantages—The inherently slower dynamic response of this system decreases the injector’s usable flow range. The Q of an injector used with this type of circuit is more duty cycle sensitive due to heat dissipation considerations. This driver’s inductive suppression, which may be resistance, capacitance or zener, significantly affects the injector’s Qd rates due to variations in the circuit’s current decay rate. This decay results in a change of the injector’s closing time.</TD></TR></TABLE>
Bottoz
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Re: Saturated vs Peak and Hold (vtec.dc2)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec.dc2 »</TD></TR><TR><TD CLASS="quote">i think 92+ civics/integra all had 240cc injectors - saturated</TD></TR></TABLE>
can anyone confrim this?
-So if I read it correctly, Injectors don't matter on what ODB you run correct?
If the injectors are in questions its more about the injector clip correct?
can anyone confrim this?
-So if I read it correctly, Injectors don't matter on what ODB you run correct?
If the injectors are in questions its more about the injector clip correct?
Re: Saturated vs Peak and Hold (Bottoz)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bottoz »</TD></TR><TR><TD CLASS="quote">Some of you may be wondering what the difference is between high and low impedance injectors. High impedance injectors are used with Saturated Drivers. Low impedance injectors are used with Peak and Hold Drivers or with Saturated drivers when used in conjuction with a ballast resistor (resistor box). The following, taken from SAE J1832 Nov 1989 - Gasoline Fuel Injector, defines each method and also lists the advantages and disadvantages to each.
SA
*WTF does SA mean
*I thought that Peak & hold are low impedance that USE a reistor(ballast) box and Saturated are high impendace that DONOT use resitor box... but that last sentance complete switched it around. Can someone please clearify?
Injector Driver—An electronic circuit that supplies voltage pulses to an electromagnetic fuel injector for a precise increment of time and at a given repetition rate. The accuracy of these pulses and their repetition is
normally ±0.001 ms. The peak-hold driver and the saturated driver are most commonly used by the industry for vehicle applications.
PEAK-HOLD DRIVER—A driver that uses two levels of current to operate the injector. The driver circuit applies battery voltage to the injector until a predetermined current level is reached. The current is then reduced and held at a lower level for the duration of the PW. This type of driver is normally used with injectors having low resistance coils (typically around 2 ohm). The accuracy of the driver peak current level (Ip) and the hold current level (Ih) is held to ±0.50%.
*WTF does PW and Ip or Ih mean?
*what are the referring to when they say DRIVER
Advantages—The high peak current minimizes OT response and the low hold current minimizes CT response. This method of control results in an increased linear range of injector operation.
*what does CT mean?
Disadvantages—Heat is primarily dissipated at the driver. Circuitry is more complex than that of the saturated driver.
[B]**what do they mean by "dissipated heat at the DRIVER?????B]
SATURATED DRIVER—A power transistor driver that turns fully on for the entire duration of the injector PW. This type of driver is used with injectors having high resistance coils (typically 12 to 16 ohm) or with injectors having low resistance coils in combination with a ballast resistor.
----please clearify what saturated injectors use a ballast/resitor box as stated in that last sentance
Advantages—Heat is primarily dissipated through the injector or ballast resistor and not at the driver circuit. Circuitry is simplified compared to the peak-hold driver.
Disadvantages—The inherently slower dynamic response of this system decreases the injector’s usable flow range. The Q of an injector used with this type of circuit is more duty cycle sensitive due to heat dissipation considerations. This driver’s inductive suppression, which may be resistance, capacitance or zener, significantly affects the injector’s Qd rates due to variations in the circuit’s current decay rate. This decay results in a change of the injector’s closing time.
so in a nut shell SATURATED injectors have a slower reponse thus for not being able to be as adjustable VS. peak/hold injectors?
</TD></TR></TABLE>
what the hell do they mean when they keep referring to DRIVER?
SA
*WTF does SA mean
*I thought that Peak & hold are low impedance that USE a reistor(ballast) box and Saturated are high impendace that DONOT use resitor box... but that last sentance complete switched it around. Can someone please clearify?
Injector Driver—An electronic circuit that supplies voltage pulses to an electromagnetic fuel injector for a precise increment of time and at a given repetition rate. The accuracy of these pulses and their repetition is
normally ±0.001 ms. The peak-hold driver and the saturated driver are most commonly used by the industry for vehicle applications.
PEAK-HOLD DRIVER—A driver that uses two levels of current to operate the injector. The driver circuit applies battery voltage to the injector until a predetermined current level is reached. The current is then reduced and held at a lower level for the duration of the PW. This type of driver is normally used with injectors having low resistance coils (typically around 2 ohm). The accuracy of the driver peak current level (Ip) and the hold current level (Ih) is held to ±0.50%.
*WTF does PW and Ip or Ih mean?
*what are the referring to when they say DRIVER
Advantages—The high peak current minimizes OT response and the low hold current minimizes CT response. This method of control results in an increased linear range of injector operation.
*what does CT mean?
Disadvantages—Heat is primarily dissipated at the driver. Circuitry is more complex than that of the saturated driver.
[B]**what do they mean by "dissipated heat at the DRIVER?????B]
SATURATED DRIVER—A power transistor driver that turns fully on for the entire duration of the injector PW. This type of driver is used with injectors having high resistance coils (typically 12 to 16 ohm) or with injectors having low resistance coils in combination with a ballast resistor.
----please clearify what saturated injectors use a ballast/resitor box as stated in that last sentance
Advantages—Heat is primarily dissipated through the injector or ballast resistor and not at the driver circuit. Circuitry is simplified compared to the peak-hold driver.
Disadvantages—The inherently slower dynamic response of this system decreases the injector’s usable flow range. The Q of an injector used with this type of circuit is more duty cycle sensitive due to heat dissipation considerations. This driver’s inductive suppression, which may be resistance, capacitance or zener, significantly affects the injector’s Qd rates due to variations in the circuit’s current decay rate. This decay results in a change of the injector’s closing time.
so in a nut shell SATURATED injectors have a slower reponse thus for not being able to be as adjustable VS. peak/hold injectors?
</TD></TR></TABLE>
what the hell do they mean when they keep referring to DRIVER?
Member
Joined: Aug 2003
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From: Atlanta, GA, USA
Re: Saturated vs Peak and Hold (Muckman)
Hey to keep it simple and easy to understand Zdyne I believe has the best detailed explanation.
http://www.zdyne.com/
Call them to if you have more q's
http://www.zdyne.com/
Call them to if you have more q's
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Joined: Oct 2001
Posts: 4,611
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From: Severn, MD
Re: Saturated vs Peak and Hold (Charlie Moua)
Driver = Transistor and associated circuitry
So your first statement that they "completely switched it around" is untrue. Each driver has a specific impedance it likes to work with. Since 92+ ECU's use saturated drivers, you can use P&H injectors with a ballast resistor to obtain the same impedance that a saturated injector provides to the driver.
PW = pulse width
Ip = I pull...or the pull-in current...the current initially needed to open the injector
Ih = I hold...or the hold current...the current needed to hold the injector open
When current passes through a resistance, power, or heat is generated. P = I^2 * R....which basically says when resistance goes up, so does the power dissipated from it. Since P&H are low ohm, compared to saturated, the driver circuitry for the P&H injectors takes the brunt of heat dissipation.
P&H injectors do respond faster than saturated injectors....but I've never been a fan of people using P&H/ballast resistors with a saturated driver.....obviously the circuitry is NOT the same. People have been doing it for awhile now, so I'm not one to argue with results, but its not my cup of tea.
So your first statement that they "completely switched it around" is untrue. Each driver has a specific impedance it likes to work with. Since 92+ ECU's use saturated drivers, you can use P&H injectors with a ballast resistor to obtain the same impedance that a saturated injector provides to the driver.
PW = pulse width
Ip = I pull...or the pull-in current...the current initially needed to open the injector
Ih = I hold...or the hold current...the current needed to hold the injector open
When current passes through a resistance, power, or heat is generated. P = I^2 * R....which basically says when resistance goes up, so does the power dissipated from it. Since P&H are low ohm, compared to saturated, the driver circuitry for the P&H injectors takes the brunt of heat dissipation.
P&H injectors do respond faster than saturated injectors....but I've never been a fan of people using P&H/ballast resistors with a saturated driver.....obviously the circuitry is NOT the same. People have been doing it for awhile now, so I'm not one to argue with results, but its not my cup of tea.
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Joined: Feb 2004
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From: Canada
Re: Saturated vs Peak and Hold (Muckman)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman »</TD></TR><TR><TD CLASS="quote">Wow my thread, back from the dead. Good information tho! 
</TD></TR></TABLE>
And I'm about to bring it back...
I've got OBD1 H22 Injectors, 345cc saturated so I've been told. They're in a OBD0 Civic with an LSVTEC... Can't get to run correctly. Runs rich @ 28PSI and fouls out plugs in a matter of minutes. I have a resistor box and I ran fine with the B16 injectors.
Is there a way to make these damn prelude injectors work for my application? Or do I need a set of peak and hold injectors?
Thanks!
</TD></TR></TABLE>And I'm about to bring it back...
I've got OBD1 H22 Injectors, 345cc saturated so I've been told. They're in a OBD0 Civic with an LSVTEC... Can't get to run correctly. Runs rich @ 28PSI and fouls out plugs in a matter of minutes. I have a resistor box and I ran fine with the B16 injectors.
Is there a way to make these damn prelude injectors work for my application? Or do I need a set of peak and hold injectors?
Thanks!
Honda-Tech Member
Joined: May 2006
Posts: 58
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From: johor bahru, johor, malaysia
Re: (T-RO)
i'm running 90 pr3 b16a with h22a injectors with vafc2... i'm facing with rough iddling, hard to start when the engine hot and engine'll self off after i floor the paddle... is it due to saturated injectors...? do i need to install h22a ballast...? technically what happened...?
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