Remember Me? What's New? Results 1 to 8 of 8. February 6th, 1.
Explained: The Difference Between Lambda and AFR
I'm trying to set up to log for the first time. I'm following E38 vve how to. But EFIlive is set to lambda. I am using an LC-1 connected with a serial cable if it matters. Any help would be appreciated. February 6th, 2. It will depend on the fuel being used. February 7th, 3.
Thank you! I hit every button I could find to edit units and could'nt find it. February 7th, 4. February 11th, 5. New Problem Ok I tried to flash my ecm with the updated tune to log data per vve how to. I connected and tried to verify ecm status and I have a message saying that I need to launch v8 and update to newest version. My boot block is 2. If I open v8 and check It says I have the newest version.
Here is a copy of my tune. Z06 logging attempt. Last edited by joecar; February 13th, at AM. Reason: fixed metatag. February 11th, 6. For some reason it says my v2 is not compatible with this software. February 11th, 7. When you flashed the firmware into the V2, did you reformat the V2 config file system and reload the new script files?
PS: Don;t forget to take a current copy of your setup when doing this. February 11th, 8. Aparently I had a copy of v7. I am a little confused though on pids.
I loaded all pids in yellow section for e38 and all in blue for ls1b.Privacy Terms. Hondata Hondata User Forum Skip to content.
Quick links. Im using my friends s Currently running 1. It works great only logging F max IAT's which im really happy about. What kind of afr's should I be going for Also I dont really understand the vtec engagment files do I just set the to settings to the same RPM. Im trying to keep it simple but I want to clean up my tune.
Also one more stupid question Do I need to run in closed loop to tune I still run the stock o2 sensor and then my AEM. I have pined my AEM widband to the d10 ecu pin out.
I have set in the closed loop tables the follwing. Target Voltage 0. I am seeing logs of Lambda but in the graph at the very left side I see 0. Feel free to look at my setup and suggest anything that I should do to my tune.
Its preety much a stock download. We have 94 octane here in Canada. Could I adjust my timing at all. I may be going to a dyno this weekend to see what its putting down for power and may have a tuner on hand so any suggestions would be great. Thanks Shane. You do not have the required permissions to view the files attached to this post.
Board index All times are UTC.Login to Your Account. Remember Me? Page 1 of 3 1 2 3 Last Jump to page: Results 1 to 10 of Thread Tools Show Printable Version. Asking for reasons of gas to E Lambda being 1. If I leave it in Gasoline mode, will E85 show up as Just wondering because I'd like to put some E85 gas in the car at the track, but want to know if it's going to be really just a Lambda scale or if it will read some other AFR? I'm not planning on draining the tank, it will basically make it a mix, that I can't choose in the ECU because there's no flex fuel options.
And I might not push it to the extreme limit of E85, but I can put it on the ragged edge of gas, and it will still be safe because of the E85 blend.
Originally Posted by S2H. May God's grace bless you in the Lord Jesus Christ. Join Date Feb Posts 4. Originally Posted by 06x6spdGTO. This way the changes from E85 to Gasoline would subtract the multiply the 4 base tables x. Join Date Sep Posts Well, I did suggest it to Holley, but I don't know if it will ever happen. Originally Posted by Danny Cabral. Page 1 of 3 1 2 3 Last Jump to page:. About us Holley has been the undisputed leader in fuel systems for over years.
Join us. All right reserved.Air—fuel ratio AFR is the mass ratio of air to a solid, liquid, or gaseous fuel present in a combustion process.
The combustion may take place in a controlled manner such as in an internal combustion engine or industrial furnace, or may result in an explosion e. The air-fuel ratio determines whether a mixture is combustible at all, how much energy is being released, and how much unwanted pollutants are produced in the reaction.
Typically a range of fuel to air ratios exists, outside of which ignition will not occur. These are known as the lower and upper explosive limits. In an internal combustion engine or industrial furnace, the air-fuel ratio is an important measure for anti-pollution and performance-tuning reasons.
If exactly enough air is provided to completely burn all of the fuel, the ratio is known as the stoichiometric mixture, often abbreviated to stoich. Ratios lower than stoichiometric are considered "rich".
Rich mixtures are less efficient, but may produce more power and burn cooler. Ratios higher than stoichiometric are considered "lean. Some engines are designed with features to allow lean-burn. For precise air-fuel ratio calculations, the oxygen content of combustion air should be specified because of different air density due to different altitude or intake air temperature, possible dilution by ambient water vaporor enrichment by oxygen additions.
In theory a stoichiometric mixture has just enough air to completely burn the available fuel. In practice this is never quite achieved, due primarily to the very short time available in an internal combustion engine for each combustion cycle. Catalytic converters are designed to work best when the exhaust gases passing through them are the result of nearly perfect combustion.
A stoichiometric mixture unfortunately burns very hot and can damage engine components if the engine is placed under high load at this fuel—air mixture. Due to the high temperatures at this mixture, detonation of the fuel—air mix while approaching or shortly after maximum cylinder pressure is possible under high load referred to as knocking or pingingspecifically a "pre-detonation" event in the context of a spark-ignition engine model. Such detonation can cause serious engine damage as the uncontrolled burning of the fuel air mix can create very high pressures in the cylinder.
As a consequence, stoichiometric mixtures are only used under light to low-moderate load conditions. For acceleration and high-load conditions, a richer mixture lower air—fuel ratio is used to produce cooler combustion products and so avoid overheating of the cylinder head, and thereby prevent detonation.
The stoichiometric mixture for a gasoline engine is the ideal ratio of air to fuel that burns all fuel with no excess air. For gasoline fuel, the stoichiometric air—fuel mixture is about The fuel oxidation reaction is:. Any mixture greater than These compounds all alter the stoichiometric ratio, with most of the additives pushing the ratio downward oxygenators bring extra oxygen to the combustion event in liquid form that is released at time of combustions; for MTBE -laden fuel, a stoichiometric ratio can be as low as Vehicles that use an oxygen sensor or other feedback loop to control fuel to air ratio lambda controlcompensate automatically for this change in the fuel's stoichiometric rate by measuring the exhaust gas composition and controlling fuel volume.
Vehicles without such controls such as most motorcycles until recently, and cars predating the mids may have difficulties running certain fuel blends especially winter fuels used in some areas and may require different jets or otherwise have the fueling ratios altered to compensate. Vehicles that use oxygen sensors can monitor the air—fuel ratio with an air—fuel ratio meter.
In the typical air to natural gas combustion burner, a double cross limit strategy is employed to ensure ratio control. This method was used in World War II. This assures ratio control within an acceptable margin.Remember Me? What's New? Results 1 to 11 of Thread Tools Show Printable Version. I looked around and couldn't find a simple chart so I put this together for me and others to use. Last edited by jmac; at PM.
That would be helpful! Since most fuels out now are E10 another chart with Simple chart. That is not correct at all. You can have a commanded AFR of EQ is another story when E is in the system The O2 sensor is not use the way most people think.
The PCM drives the injectors to drive the O2 sensor to a given voltage on some vehicles and the driven the oposite dirrection. On some vehicles they use a switching point without the high low setting, but it has other settings also. Swap the O2 sensors connectors and see how the engine runs. Originally Posted by c. I guess my point is the AFR doesn't realy mater I have a question for you.
Lambda / AFR Table
Will a narrow band O2 sensor work on with an AFR of 8 to 1? Not on any fuel I know of? Stoich of fuel would have to be 8 to 1 AFR On to E10, I've seen stoich of Is there really that much difference in fuels that these numbers seem to change? State to state or? Forget AFR all together After that Lambda or EQ is easiest to use and universal.
Lambda and EQ are the same only the inverse of one another. James Short - James ShorTuning. Originally Posted by LSxpwrdZ. Can we add NGC commanded afr in here?
That's a horrible think to calculate all the time. All times are GMT For best performance, tuning of a racing engine involves fuel mixture control due to atmospheric air density changes and engine setup changes. Sometimes fuel mixture control is done based on record-keeping of past runs or by trial-and-error.
In these cases, the goal is to reproduce a tune-up that was used successfully under similar weather and location conditions. This is how electronic fuel injection EFI tuning works. Racing mechanical fuel injection tuning and carburetor tuning can work that way also. Sprint car engines run AFRs from 6 to 1 down to 3. That necessitated an AFR change to 4. The stoichiometric point is the AFR where all of the oxygen in the air burns with all of the fuel. At the stoichiometric ratio, only burnt exhaust byproducts are in the exhaust gas mix with no excess, unconsumed oxygen or fuel.
Different fuels have different chemical makeups, and thereby different stoichiometric ratios. Using methanol as an example, the stoichiometric AFR is approximately 6. That is, 6. In racing, however, running a rich methanol mixture instead of a stoichiometric mixture is routine for the additional engine cooling and accelerator pump shot for throttle response. In high-compression engines or engines with forced-induction, rich mixtures cool the cylinder contents and help avoid detonation.
Typically, a rich methanol AFR is around 5 to 1 for a high-compression naturally aspirated racing engine with mechanical fuel injection MFI. Jack-rabbit starts for fastest foot times were maintained with a launch AFR at 3.
A richer launch AFR of only a small difference at 3. That consequence was from a small bypass jetting size difference of only 0. The amount of enrichment is important for tuning. If it is too little, the engine will run too hot or detonate. If it is too rich, power will be reduced.
An easy way to determine the amount of enrichment required, from the AFR is as follows:. Optimum AFR combinations for long courses are different than those for short courses. Shorter courses can be run with low-end AFRs that are richer for response. Longer courses can be run with high-end AFRs that are less rich for more power.
Optimum AFRs for dirt track are different than those for pavement.Thermal engines use fuel and oxygen from air to produce energy through combustion. To guarantee the combustion process, certain quantities of fuel and air need to be supplied in the combustion chamber. A complete combustion takes place when all the fuel is burned, in the exhaust gas there will be no quantities of unburned fuel.
Air-fuel ratio AF or AFR is the ratio between the mass of air m a and mass fuel m fused by the engine when running:. The ideal theoretical air-fuel ratio, for a complete combustion, is called stoichiometric air-fuel ratio. For a gasoline petrol engine, the stoichiometric air-fuel ratio is around This means that, in order to burn completely 1 kg of fuel, we need The combustion is possible even is the AFR is different than stoichiometric.
For the combustion process to take place in a gasoline engine, the minimum AFR is around and the maximum can go up to When the air-fuel ratio is higher than the stoichiometric ratio, the air-fuel mixture is called lean. When the air-fuel ratio is lower than the stoichiometric ratio, the air-fuel mixture is called rich.
For example, for a gasoline engine, an AFR of For example, in order to burn completely 1 kg of ethanol, we need 9 kg of air and to burn 1 kg of diesel fuel, we need Spark ignition SI engines usually run on gasoline petrol fuel.
The AFR of the SI engines varies within the range rich to leandepending on the operating condition of the engine temperature, speed, load, etc.
Modern internal combustion engines operate as much as possible around the stoichiometric AFR mainly for gas after-treatment reasons. Compression ignition CI engines usually run on diesel fuel. Due to the nature of the combustion process, CI engines always run on lean mixtures, with AFR between and The main difference, compared with SI engines, is that CI engines run on stratified non homogeneous air-fuel mixtures, while SI run on homogeneous mixtures in case of port-injection engines.
In order to understand how the stoichiometric air-fuel ratio is calculated, we need to look at the combustion process of the fuel. Combustion is basically a chemical reaction called oxidation in which a fuel is mixed with oxigen and produces carbon dioxide CO 2water H 2 O and energy heat. Take into account that, in order for the oxidation reaction to occur we need an activation energy spark or high temperature. Also, the net reaction is highly exothermic with heat release.
Step 4. Calculate the mass of fuel, which is 1 mol of methane, made up from 1 atom of carbon and 4 atoms of hydrogen. Step 5. Calculate the mass of oxygen, which consists of 2 moles, each mol made up from 2 atoms of oxygen. Step 6. The calculated AFR for methane is not exactly as specified in the literature. The same method can be applied for the combustion of gasoline.
Considering that gasoline is made up from isooctane C 8 H 18calculate the stoichiometric air-fuel ratio for gasoline.