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Thread: Fuel Adjustment

  1. #1

    Default Fuel Adjustment

    With #160 injectors, when making a fuel adjustment, how much fuel before you actually notice a change?
    2nd question using an example, if DA dropped say 500 feet, how much fuel would I need to add? (Say with 46 jets.)
    Last edited by odie; 02-21-2013 at 09:40 PM.

  2. #2
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    Quote Originally Posted by odie View Post
    With #160 injectors, when making a fuel adjustment, how much fuel before you actually notice a change?
    (Say with 46 jets.)
    What "fuel adjustment" are you referring to?
    Also, what "46 jets"? Nitrous oxide jets?
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  3. #3
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    Quote Originally Posted by odie View Post
    2nd question using an example, if DA dropped say 500 ft how much fuel would I need to add?
    1) For elevation changes, the Target Air/Fuel Ratio stays the same (read Part II of the article below).
    So you can rely on the Closed Loop Compensation Limits to correct the amount of fuel injected.
    It's the actual injected fuel that will be less; less air density requires less fuel to achieve the same AFR.
    Set the Closed Loop "Advanced Control" & Learn "Base Fuel Learn Gain" relatively high for quick ECU adjustability.

    2) Base Timing Table configuration for mild elevation changes:
    Tune the Timing Table as usual, including WOT, at high elevation (80± kPa).
    Tune the WOT Timing Table near sea level (100± kPa) and linearly blend the WOT MAP rows in between.
    The timing values in row 80± kPa are usually higher anyway, than row 100± kPa; so we're still retarding in the same direction.
    Use the knock sensor capability to possibly retard timing (in some areas) while driving at lower elevations, which may not require as much timing advance.

    After some researching, the general consensus among most people with aftermarket EFI, is simply adding 3°-5° of timing at higher elevations (after all, it is user programmable EFI). However, I think the method outlined above is practical for someone who lives and drives primarily at high elevation. This should work well for mild elevation changes, but not for very high elevation situations, because the engine won't tolerate that much ignition advance at low elevation. Even with a knock sensor, it's not the right way to tune.

    The options for major elevation changes, is to:
    A) Manually advance or retard ignition timing from the Base Timing Table in EFI software.
    Or
    B) Create a second engine file for a different elevation (name it as such), and switch to it.
    Or
    C) Use an Advanced 2D Table (V4 Advanced ICF) to perform a "Timing Offset".
    (Ignition timing advance based on the ECU's barometric pressure sensor.)
    Record a datalog at both elevations to ascertain the "Baro" channel values.
    Create an Advanced 2D Table to increase timing at the higher elevations.
    Table Type: Timing Offset, X Axis: Baro, Y Axis: MAP, Advanced Enable: Baro, Above kPa.

    Dominator ECU owners, Holley has a Multi-Map Selector (key switch) that allows
    switching between four different engine files without a laptop computer in the vehicle.
    However, if you only need two Global Folders, then a simple toggle switch is all that's required.
    Normally open is the regular GF, and grounded (pin B17 - P3 connector) is the 2nd/alternate GF.

    FYI: The 3.5" & 5.7" LCD Touchscreens can also change Global Folders (create a non-sequential emergency GF), by
    storing them on the SD Card. It's quick & easy (like the Multi-Map Selector switch), and it's great for HP ECU owners.
    And now the Digital Dash is also capable of storing/changing Global Files, except it's stored on a USB flash drive.
    ---------------------------------------------------------------------------------------------------------------------------------------------

    This three part article is written by Ben Strader of EFI University. (I contacted EFI University for this complete document and permission to post it.)
    Quote Originally Posted by Ben Strader
    Air/Fuel Ratio Management For Racers, A Three Part Series

    When it comes to racing, there is never any shortage of hard work and chores to be done before the next event. Often, race teams are required to travel long distances during the week, prep the car, show up on the weekend ready to run, and then do it all over again the next week. This doesn’t leave much time for experimentation and trying out new concepts. That means most of the time, when racers find something that works okay they tend not to change it, even though there might be a better way. They simply can’t afford to risk missing an event or losing a race.
    Often times a discussion arises about the best Air to Fuel ratio to use for various tracks and atmospheric conditions. I want to try and address a few of these questions in this series.
    Here is a list of some common questions asked by racers and tuners:
    1) What Air to Fuel Ratio gives the best power?
    2) Does the Air to Fuel Ratio that produces the best power change as the altitude my car operates at changes?
    3) Does the Air to Fuel Ratio that produces the best power change as the intake air temperature my car operates at changes?
    To find answers to these questions I have spent years on the dynamometer testing various engine combinations, talking with other knowledgeable tuners, reading various publications on the subject, and even wrote a book about tuning Electronic Fuel Injected engines, but I found the most convincing answers to these questions in a document written in 1922 by Stanwood Sparrow of the “Bureau of Standards” for the “National Advisory Committee for Aeronautics” (NACA), called NACA Report #189 “Relation of Fuel-Air Ratios to Engine Performance”.
    In this report, a government agency set out to answer these and many other questions about the effect of Air Fuel Ratios on engine performance over a wide range of parameters, and the evidence proves out many of the answers I am about to present to you for the above questions in this three part series.

    PART I
    What Air to Fuel Ratio gives the best power?
    Many folks have tried to shed light on this subject based on single-case observations made in sloppily controlled test environments which show results of all sorts, and yet other, seemingly more knowledgeable sources, (such as the companies trying to sell Air-Fuel ratio meters) are constantly trying to convince us that while they cannot (for reasons of liability) tell us what the magic number is, we cannot possibly hope to achieve maximum engine performance without the help of one of their whiz-bang doo-hickeys!
    Well, according to NACA report 189, a wide variety of engines were tested across a large range of Air/Fuel ratios and what they found was basically the following:
    “In adjusting the carburetor to obtain maximum power, The following method was employed. First, the mixture was altered until approximately maximum power (for the chosen set of conditions) was obtained. As will be shown later, values of power within 1 percent of maximum are obtained over a wide range of fuel-air ratios. Hence, little difficulty was experienced in finding an Air/Fuel ratio to give approximately maximum power.”
    The report goes on to state later that, “From the results to date it is concluded that ordinarily maximum power (at least in so far as aviation engines are concerned) is obtained with gasoline-air ratios of between 0.07 and 0.08 pounds of fuel per pound of air (12.5 to 14.5 pounds of air per pound of fuel).”
    What all this means is that basically, if simply making lots of power is your only goal, nearly any Air/Fuel ratio can get you pretty close to the mark.
    This corresponds quite closely to what my years’ of engine testing have show as well, and in fact, this is what we have been teaching at EFI University for almost four years, but what I find surprising is the number of supposedly “expert” tuners out there who are still arguing against this point, and pretending that what they do is a special brand of “Magic”.
    My experience has been that typically the best engine tuners in the business are the first ones to say: “Ask me anything you like, I have nothing to hide.” Recently, I spoke with Shane Tecklenburg of FAST Motorsports in Huntington Beach, California, who is widely regarded to be one of the finest engine tuners in the USA, and he had this to say: “Nothing I do is black magic. Everything is based on simple laws of physics that anyone can learn with a little effort, so there is no reason for me not to answer a racer’s question about engine tuning, even if he is a competitor.” I have also spoken to a number of other well known tuners who have had quite the opposite attitude and tried to make it seem as if they knew some special trick or held the golden nugget of knowledge that, if shared with others would seriously jeopardize their standing. Most of the time, when I find a tuner with this attitude, it means they don’t actually know the answers and fear they might reveal this ugly fact if they say too much.
    The simple fact is, ten years ago, before the age of $300 widebands for everyone, nobody even knew what their Air Fuel Ratios were. The rule of thumb was to change the jets one size for every one-thousand feet of elevation, and that was just the way it was. We looked down the tailpipes and at our spark plugs for various color patterns, and even that wasn’t an exact science.
    Most racers would have been horrified if they actually saw what the A/F ratios were doing in their engines during a run, but because the engine still performed well, no one cared. What has changed the industry so dramatically in recent years is the advent of the low-cost wide-band Air/Fuel ratio meters. Suddenly, everyone could afford access to this tool to gain priceless insight into their engine’s performance, and then “numbers game” began.
    It is not uncommon to go to the racetrack these days and find any number of racers with their laptops plugged into their cars trying to get that last tenth of an A/F point in line. I’ve heard guys say “yesterday she was running a 12.8 A/F ratio, and today it seems to be running about 12.7 and that’s just too rich!” I wonder if either their dyno, or their E.T.’s would support that. If what the NACA report says is true, then I suppose it begs the question, “What is to be gained by agonizing over minute changes in A/F ratios”? Isn’t there some other chassis or tire component that would be better served by spending this time tweaking them instead? What good is ultimate power if it can’t reach the ground?
    I’m not suggesting that we abandon this great new technology and throw away our wide-bands just yet. I simply want to help folks get back to the reality of what it is we are trying to accomplish: Getting the maximum performance from the engine… not getting bogged down in the data. Let’s all take a step back, close our eyes, take a deep breath and remember, the only numbers that really matter are not the ones on the wide-band, but the ones that say the letters “E.T.” next to them! Good luck out there folks!

    Coming up in Part II:
    Does the Air to Fuel Ratio that produces the best power change as the altitude that my car operates at changes? Tune in next time to find out!
    Quote Originally Posted by Ben Strader
    Hello again everyone! It’s time for another installment of our three part series called “Air/Fuel Ratio Management For Racers”! In our last issue, we discussed ways to evaluate the correct ratio of air and fuel for your engine when trying to make maximum power. We used a paper written in the 1920’s that contains evidence, which still holds true today! The thing is, making max power is one of the easier tasks involved in mapping an EFI equipped engine. The hard part is getting the consistency, and reliability out of the engine that will win races!

    So, once you’ve tuned your engine on a dyno at one location, what happens if you go racing somewhere else? Will the altitude and air density changes dramatically affect the engine, and if so, should you be thinking about using a different air/fuel ratio to maintain the best power? Let’s take a look!

    PART II
    When I find the right Air Fuel Ratio for maximum power, will that number change when I race at tracks of various altitudes?
    When we first start thinking about a solution to this particular problem, we must begin with a strong understanding of what happens to the engine when we change altitudes.

    First, and foremost, it is extremely important for us to recognize that as we gain altitude, the air gets both thinner and colder. We say that the “density” of the air is less.
    Density of the air can be described as the “weight per unit of volume”. What I mean is this: If we have two empty one-gallon milk jugs sitting on a table and we fill one all the way to the top with goose feathers and one all the way to the top with sand, it should be obvious to most folks that the gallon of sand will weigh more, even though both containers have the same unit of volume: one gallon.
    So, the air we breathe, much like the air our engines draw in, gets less dense as we go up in altitude, but the volume of air inside the engine does not change. We say that the “Volumetric Efficiency” of our engine stays the same!
    So, if the engine’s Volumetric efficiency is the same at any altitude, then why does the engine make less power when we go up?
    Because the quantity of air we are concerned about when supplying fuel to the engine is called the “Mass” of air. The “Mass” is determined by multiplying the volume of air you have by what it weighs.

    So, M = V x D, where:
    M = Mass in Lbs/ minute
    V = Volume of air in CFM
    D = Density in Lbs/ Cubic Ft

    So, if our engine is flowing 650 CFM for example, then at sea level where one cubic foot of air weighs about .076 pounds we would have a Mass of about 49.4 Lbs of air per minute.
    Ex: 650 * .076 = 49.4

    However, if we take the engine up to the top of a mountain where one cubic foot of air might only weigh .064 pounds, we would only net 42.18 Lbs of air per minute!
    Ex: 650 * .064 = 42.18

    That’s about a 15% reduction in power at the SAME volumetric efficiency!
    So, the question becomes then, since I’m making 15% less power, should I change the A/F ratio to be 15% leaner?
    The answer: NO! Leave it the same.

    We are talking about a “ratio” of air to fuel, so since the air is 15% less, we will want the fuel to be 15% less as well, which would still net the same Air to Fuel Ratio!
    This means we can build some automatic compensation tables into our ECU settings to detect a change in altitude or barometric pressure and add or subtract fueling as necessary. Wouldn’t that make life so much easier?

    If we reference our previous document, “NACA Report #189 “Relation of Fuel-Air Ratios to Engine Performance” to try and solidify the above statements we’ll see what our old buddy Stanwood Sparrow has to say.
    On page 111 of the report, we find following:
    These tests were done at various air pressures from sea level all the way to 30,000 feet in elevation, and the results show that it is desirable to maintain the same ratio of air to fuel at all altitudes.

    Of course, what we are talking about here is only the A/F ratio that produces maximum power. This is not to say that better fuel economy might not be possible by a reduction in A/F ratio due to the fact that since we are making less overall power, we may not need as much fuel for cylinder cooling, and could find some savings there. Then again… we are talking about RACING, not grocery shopping, so lighten up a little and get out there and have fun!

    There are always a lot of variables in engine tuning that we could continue to converse about until the cows come home, but the only thing left to answer in our three part series is whether or not we would need a different A/F ratio when the intake air temperatures get hotter or colder.

    Tune in next time for an in depth description of how air temperatures affect air density, as well as how they affect the way our engine runs! See you there.
    Quote Originally Posted by Ben Strader
    Hello again everyone! It’s time for the final installment of our three part series called “Air/Fuel Ratio Management For Racers”! In our last issue, we discussed how the engine reacts if we tune it on a dyno or at a track in one location and then take the engine to a totally different altitude or location. We found a government study put out in the 1920’s shows that the same air to fuel ratio would be required of the engine at any reasonable altitude. The engine made less power overall due to the lack of air density, but the ratio of air to fuel did not need to be changed because of this. Knowing this, the only thing a racer needs to do is make sure to maintain the same air fuel ratio at the track that they found to work when they were on the dyno!

    In this final article of the series, we wanted to ask the question: “What happens to my engine at various inlet air temperatures, and how does this affect my choice of air fuel ratios?” Let’s take one last look at our favorite document, “NACA report 189” to see if we can find the answer!

    PART III
    When I find the right Air Fuel Ratio for maximum power, will that number change when I race at tracks with different temperatures?.

    If you’ll remember back to the last article, we used a mathematical formula to calculate the mass of air that went something like this:
    Mass = V*D
    Where:
    V = the CFM of air the engine was breathing,
    and
    D = the density, (or weight) of one cubic foot of air.

    There are primarily two things that affect the density of air. One is the air pressure, and the other is the air temperature.
    We can use the following formula to determine how much one cubic foot of air weighs:
    Density = 2.7 P/T
    Where:
    P = PSI (absolute)
    And
    T = Temperature in degrees Rankine (Degrees F + 460)

    If we use the standard temperatures and pressures at sea level, we will find that one cubic foot of air weighs around .076 Lbs.
    Ex: 2.7 [14.7/(60 + 460)] = .076

    Now, if we simply plug in different values for various altitudes or temperatures, we can find out how much change in air density we have and then add or subtract fuel from the engine accordingly to maintain the same air to fuel ratio.
    Take a look:
    Let's say we are up in the mountains, and the barometric pressure is down to around 12 psi absolute, (which is around 24.4 inches of mercury, or about 82 kPa), and the outside temperatures are about 40 degrees F.

    Using the above formula, we see that:
    D = 2.7 P/T
    D = 2.7 [12/(40 + 460)]
    D = .0648 Lbs per cubic foot
    So, .0648 / .076 = .85 or about 85% of the original air density at sea level!

    That means in order to keep the same air to fuel ratios, we would need to subtract about 15% of the fuel we were previously giving the engine!
    We can very easily program a table into the engine computer to automatically measure the intake air temperatures, and then add or subtract fuel to maintain a constant air fuel ratio at all temperatures.

    The question is though, do we need a different air fuel ratio when the air gets very hot, or very cold?
    Well, to find the answer, we must once again visit “NACA Report 189”.
    On pages 111 and 112 we see this following statements, (which are paraphrased here):
    “An analysis of a large number of tests covering an inlet temperature range of –20 C to +40 C has shown maximum power to be obtained with approximately the same air fuel ratios at each temperature.”

    This would indicate that one would always want the same air fuel ratio, regardless of the inlet temperatures. However, the report goes on to state the following:
    “The volatility of the fuel is in reality the determining factor in this question. A constant fuel air ratio is desirable only so long as a change in air temperatures does not appreciably change the relative quality of the mixtures supplied to the various cylinders or the amount of fuel that has been vaporized at the time the compression stroke is completed.”

    Essentially, what they are saying is that if the intake temperatures are so hot or cold that they cause the fuel to be ignited prematurely, causing detonation, or cause the fuel to remain in a more liquefied, unvaporized state, which would make it not ignite so easily then the need for a richer or leaner air fuel ratio might exist.

    Overall, what we learned from this is that if the fuel being used is fairly stable, and the temperatures encountered while racing are not extreme, then a constant air fuel ratio is desirable across a wide range of air temperatures. If however, the temperatures your engine will see are extreme, then there is a possibility that a change in air fuel ratios might be warranted.

    However, most ECU manufacturers have understood this for some time, and nearly all give you one or more tables to create a method for adding or subtracting fuel as the inlet temperatures increase or decrease.

    Hopefully, this series of articles has given you a small amount of insight into understanding the engine’s requirements when it comes to selecting, and maintaining a given air fuel ratio. Only thorough testing and some trial and error will tell you what is exactly right for your engine, but perhaps with a better understanding of the factors involved we can shorten the time spent tuning, and increase the time spent racing and enjoying your vehicles! See you at the track!
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  4. #4

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    Sorry about not being very clear with my questioning.
    I'm running the Dominator ECU with the dry progressive feature, with N2O #46 jets and roughly 15° total timing.

    I had an experience last year with the wet progressive feature when the DA dropped almost 1000 ft with some very long down time between rounds at the track.
    Being inexperienced and without any changes to the tune, it backfired on the launch. The car was running really well till then.

    I was told that it was a lean backfire. Now I'm trying to learn how to prevent this from ever happening again with my Holley EFI.
    Should I have added more fuel to the Fuel Enrichment? And if so, how much and would I add it equal across the map?
    Thanks for all your help, I want to do all my own tuning this year and need all the help I can get from you guys.

  5. #5
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    Quote Originally Posted by odie View Post
    I was told that it was a lean backfire.
    Should I have added more fuel to the Fuel Enrichment?
    Page 12 of this NOS document states, 30 lbs/hr of fuel - per 100HP N2O is a good start:
    http://documents.holley.com/199r10585rev2.pdf (EFI Dry NOS Kits)
    http://www.yellowbullet.com/forum/sh...82&postcount=2 (Quote from Doug F, Chief EFI Engineer at Holley.)
    http://www.yellowbullet.com/forum/sh...0&postcount=10 (Quote from Doug F, Chief EFI Engineer at Holley.)
    https://www.facebook.com/InductionSo...4770887212440/ (Bottle Pressure Video - Steve Johnson, Induction Solutions)

    And if so, how much and would I add it equal across the map?
    This is determined by datalogging smaller N2O shots, reviewing the Closed Loop operation, then adjusting the Added Fuel Enrichment.
    The Closed Loop Compensation % is for TOTAL fuel flow (Base Fuel Table, Learn Table and N2O Added Fuel Enrichment).
    The ECU automatically turns the Learn Table off (while the N2O is active), but continues to operate in Closed Loop mode.
    Of course, your Fuel Table needs to be well tuned before using N2O, so you see exactly how much fuel was added or subtracted.
    According to Part II of the elevation article above, the air/fuel ratio stays the same, but the amount of fuel changes.

    Originally Posted by Danny Cabral
    Email correspondence between Doug F. & Danny Cabral
    :

    N2O Timing

    Me: Should a Time or RPM based 'Timing Retard' be used with a progressive system (as opposed to Fixed Timing)?

    Why fully retard the timing (Fixed Timing) if the total amount of nitrous isn't there initially (since it's progressive)?

    Doug F: Depends on application. For true traction limited drag racing, the timing retard is more to take out power than “safety” when you use time based.
    For something that is RPM progressive based, you could consider variable timing.
    But remember 50% duty cycle nitrous at 3000 RPM is the same per cylinder event flow at 100% at 6000 RPM.
    If that doesn’t make sense think about it. That is the “danger” of nitrous.

    Me: Yes, I understand. This link explains it well: https://www.go-fast.org/z28/new_to_nitrous.html (Read "Window Switch")

    N2O AFR
    Me: Is a nitrous Target Air/Fuel Ratio of 12.0 acceptable with eight .023 port jets (progressive 150 HP shot)?
    Or do you prefer to go richer?

    Doug F:
    To the professional tuners I work with, 12.0 is considered too rich. They run 13.0 or so at 600HP worth of nitrous.

    Me
    : I was actually expecting this answer, especially after reading this: http://www.innovatemotorsports.com/resources/rich.php
    Doug F: You can “get away with” very rich AFRs with very small shots, but the more nitrous, the quicker and over rich tune kills an engine (due to the true raw volume of fuel).

    -----------------------------------------------------------------------------------------------------------------------------------------------

    The multi-stage adjustable Timing Retards are "additive": -5° + -10° = -15° total retard. There's a lot of engine power control with timing.
    Read page 5 & 6 of the NOS Tuning Technical Information document (LINK) for suggested baseline N2O timing. Note "Combustion Efficiency".

    Nitrous ICF Tuning - Stage Retards:
    It is very important to tune the proper timing retards when using nitrous. The HP/Dominator systems allow for nitrous timing strategies to be tuned by stage. However, there are a set of “rules” that apply when using fixed timing and timing retards. Read the following and make sure you fully understand their implementation.

    1) If every stage has “fixed” timing, the highest stage activated will drive the timing (stages 1, 2, 3, or 4). So, it is best to activate the stages in order and reduce the timing accordingly as each extra stage is activated. The base timing table is completely ignored.

    2) If every stage is a “retard”, the retard is based/removed from whatever timing is commanded by the base timing table. The retards are additive.

    3) If a “fixed” timing is commanded first, then a “retard” follows, the retard is based off the “fixed” timing, not the timing table.

    4) If the first stage is a “retard”, the retard is based/removed from whatever timing is commanded by the base timing table. If the next stage is “fixed”, the timing will be whatever the fixed timing is. The base timing table and previous retard are ignored.

    EFI Software Help Information/Instructions:
    ‒ On the top Toolbar, click "Help" & "Contents". This opens all Help topics.
    ‒ When navigating the software, click "Help ?", drag it to any parameter and click again.
    ..This automatically opens the definitions for that specific parameter.
    ‒ Tuning information can be read by clicking the F1 key, when you're viewing any screen.
    http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual)
    Originally Posted by Danny Cabral
    For automatic N2O bottle heater operation, I created a custom "N2O Heater" Output (Inputs/Outputs ICF), using the N2O Pressure transducer (Holley 554-102) I installed on the N2O hose (NOS 16104NOS). The Sensor Input Trigger is "N2O Pressure", and it activates the heater below 950 psi. It has a Secondary Deactivation of 100 psi Range Mode, just in case the N2O bottle valve isn't open (safety reasons). It's programmed with the "N2O Enable" as the Switched Input Trigger ("AND" condition), so it's only enabled if the N2O system is armed (more safety reasons). In the Holley EFI software, my Global File has an Advanced 1D Table that modifies the Fuel Flow based on N2O bottle pressure compensation (see Table #3 in the V4 2016 PRI Seminar Example GF). I also have the NOS 14168NOS electric bottle valve opener, also activated by the "N2O Enable" Switched Input Trigger. The N2O Enable (N2O Opener, N2O Heater) and the N2O purge solenoid are all controlled by virtual switches on my Holley EFI Digital Dash, to keep wiring at a minimum (LINK). My entire nitrous oxide system is ECU controlled (Holley Dominator EFI - Dry/Progressive control, TPS Trigger, RPM scale range/limiter, AFR Lean/Rich Cutoffs & Delay, 2-Step rev limiter disable, Pause Enabled pedaling strategy, N2O Timing Retard, Closed Loop to new Target AFR, dual NTK WBO2 sensors). I believe the future of nitrous oxide injection is completely computer controlled; it's just much easier (cleaner) & safer on the engine.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  6. #6

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    Thanks again Danny for your help.

  7. #7
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    Quote Originally Posted by odie View Post
    I'm running the Dominator ECU with the dry progressive feature, with N2O #46 jets and roughly 15° total timing.
    #46 jets? (Singular or plural?) Is this a plate kit or a direct-port kit? How much horsepower is this kit?
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  8. #8

    Default

    8 #46 jets, direct-port, estimated 575 HP kit.

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