Lambda to afr

Jacko996
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Joined: Wed Jun 23, 2021 3:37 pm

Lambda to afr

Post by Jacko996 »

Hi
.I am receiving lamda reading and wondering if its possible to change this to afr readings ?
I have a wideband lamda
stevieturbo
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Re: Lambda to afr

Post by stevieturbo »

just open up the gauge and change the units to whatever you want.
Syvecs Ed
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Re: Lambda to afr

Post by Syvecs Ed »

Jacko996 wrote: Wed Jun 23, 2021 5:42 pm Hi
.I am receiving lamda reading and wondering if its possible to change this to afr readings ?
I have a wideband lamda
Assuming you mean in software, Right click on the gauge and choose "change units"
TimH
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Re: Lambda to afr

Post by TimH »

Pet hate of mine...WHY OH WHY use AFR!!! Lambda is fuel independent. AFR is meaningless unless you know the precise fuel mixture, which is hit and miss with pump fuel at the best of times.

Stick with lambda units, IMHO :lol:
stevieturbo
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Re: Lambda to afr

Post by stevieturbo »

resolution ease of use.

AFR IS easier.
RICE RACING
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Re: Lambda to afr

Post by RICE RACING »

TimH wrote: Thu Jun 24, 2021 7:54 pm Pet hate of mine...WHY OH WHY use AFR!!! Lambda is fuel independent. AFR is meaningless unless you know the precise fuel mixture, which is hit and miss with pump fuel at the best of times.

Stick with lambda units, IMHO :lol:
This is a misconception spread out there sadly.
AFRp (or could be dogshit) as a unit is totally irrelevant, Its just an arbitrary scale as Stevie says just use what has meaning to you end of story.

The only people it has relevance to is engineers so if you want to back calculate things like thermal efficiency or bsfc or mass used per unit of time etc then its of relevance especially to size specific items in the fuel system, you still need to know details of the fuel type to work any of those items out but to most 'tunas' they only are interested I have found in setting the fuel and for this the units that make sense to them is more important than some ones miss guided 'opinion' saying you are wrong. In this case as I have said 1 jizzilion times makes no difference if you are in petrol AFR scale or not, if you feed it Nitro methane or methanol or E85 or Yak Semen.... it will still be reading what it does (oxygen) and putting it into a scale you understand, and the understanding part is what is important more than anything else. Bit like giving a person a tape measure in metric units and they only understands imperial, no point making an old dog learn new tricks, he will still shit on your lawn :lol: EG: 1 meter still equals 0.000539957 Nautical Miles or 3.0000069 Elephant Scrotums < so if they are normal, backwards, or gender neutral and love scrotums? moral is give them what they want and are comfortable wrapping their lips around :lol:

2 decades ago we were setting up some engines running on methanol with 35% nitro methane, there was no requirement to know nor did anyone need to know what the stoich AFR was for that specific fuel, the owners did not understand Lambda had no feeling for it, but they knew AFRp scales well, so gave them guidance based off that. Just as you say Lambda is independent so too is AFRp, metric or imperial tape measure, same deal.

I personally get a hard on for equivalence ratio, it makes much more sense than anything else does since were talking in fuel terms NOT air! Remember you are adjusting a fuel table not a farking air table :lol: if you doubt me go look at any Syvecs map, running 42.9% excess fuel has meaning, 0.700 Lambada does not to 99.9% of tunas, they may say on camera that they understand it, but you can always see them fark it up when applying percentages of corrections based on difference to target... IE: they have no idea lambda really is a shit way to look at things, super miss understood, and has zero common sense for doing fuel adjustments, its basically useless IMHO. It is much better to talk in fuel terms rather than air, and you can see instantly without needing to do maths in your head and fuck it up that its got more or less fuel than required and how much it is, simple, yet no talking heads every mention it :roll: Little side note, go look at old papers they are written commonly in FAR < fuel terms :) maybe people were smarter back then? either way which ever kunt made L the prominent unit needs a good swift kick in the nut sack, same for the arse clown that thought it was a good idea to mix imperial and metric units for tires size designations :roll:
dogshit units example.jpg
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Syvecs Ed
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Re: Lambda to afr

Post by Syvecs Ed »

If you want to convert lambda to a multiplier, as in your table its simply 1/Lambda * 100 (for percent)

As an example you use 0.7 lambda and state it being a more meaningful when viewed as 42.9% excess fuel (than compared to a lambda of 1)

But to really quickly see where you are in Lambda, (1/Lambda)*100= 42.9.

Lambda is then useful to use to quickly achieve what fuel multiplier you might need to apply to achieve a certain target.

Another way of using this is to say you have current reading of 0.9 lambda, you need 0.8, but how much more fuel do you need to apply?

Current: 1/0.9=1.11
Wanted: 1/0.8=1.25

Work out the difference, 1.25-1.11=0.14 multiply buy 100, and you have 14% as the multiplier you need to apply to the section of the map that requires it.
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Re: Lambda to afr

Post by RICE RACING »

Equivalence Ratio example
13% to 15% excess fuel, again makes allot more sense and is the simplest to use too.
EQR2.jpg
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EQR 1.jpg
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TimH
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Re: Lambda to afr

Post by TimH »

Isn't that showing lambda, as "mix"?
RICE RACING
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Re: Lambda to afr

Post by RICE RACING »

TimH wrote: Mon Jul 19, 2021 10:05 am Isn't that showing lambda, as "mix"?
Nah, frogs love to talk in equivalence ratio.

0.870L to 0.885L is about right for a maximum power setting.
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