Donations towards server fund so far this month.

 
£0.00 / £100.00 per month
Page:
Home > Help Needed / General Tech Chat > Lambda v's AFR

apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

I'm trying to get the AFR gauge in my ECU (SC Typhoon 2) reading the same as my gauge (AEM UEGO Analogue Wideband 30-5130).

The ECU is configured with a table with two columns. Voltage and Lambda. Rows for 0v & 5v.

I can find the voltage v's AFR values quite easily, but can find nothing about voltage v's Lambda.

Is there a way to work out Lambda from AFR?

I have emailed AEM, but wondered if anybody with a bigger brain than me knew the answer, or is better at googling than me.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

*hehe!*


Carlzilla

User Avatar

3673 Posts
Member #: 9300
Post Whore

Quarry Bonk

Not sure if this is what youre after andy, but I did find this. http://www.wallaceracing.com/air-fuel-lambda.php

On 26th Jan, 2012 Tom Fenton said:
ring problems are down to wear or abuse but although annoying it isn't a show stopper

On 5th Aug, 2014 madmk1 said:
Shit the bed! I had snapped the end of my shaft off!!

17.213 @ 71mph, 64bhp n/a (Old Engine)


Carlzilla

User Avatar

3673 Posts
Member #: 9300
Post Whore

Quarry Bonk

Gasoline option is petrol AFR, and the lambda is obviously self explanatory!

On 26th Jan, 2012 Tom Fenton said:
ring problems are down to wear or abuse but although annoying it isn't a show stopper

On 5th Aug, 2014 madmk1 said:
Shit the bed! I had snapped the end of my shaft off!!

17.213 @ 71mph, 64bhp n/a (Old Engine)


robert

User Avatar

6743 Posts
Member #: 828
Post Whore

uranus

andy ,

lambda is a fraction of afr based on 14.7=lambda 1..

so for example ,take 12.5:1 afr

to get lambda go 12.5/14.7=0.85LAMBDA

OR 17:1

=17.5/14.7=1.19 LAMBsydasDA.

robert

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM


apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

That looks like the daddy. Thanks a lot Carl

EDIT: Thanks Robert, it looks simple when you put it like that/ *blush*

Edited by apbellamy on 22nd Jul, 2014.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

*hehe!*


apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

All being well I can get some miles on it now.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

*hehe!*


Carlzilla

User Avatar

3673 Posts
Member #: 9300
Post Whore

Quarry Bonk

No problem! Good stuff :)

On 26th Jan, 2012 Tom Fenton said:
ring problems are down to wear or abuse but although annoying it isn't a show stopper

On 5th Aug, 2014 madmk1 said:
Shit the bed! I had snapped the end of my shaft off!!

17.213 @ 71mph, 64bhp n/a (Old Engine)


BENROSS

User Avatar

9812 Posts
Member #: 332
Resident Cylinder Head Modifier

Mitsi Evo 7, 911, Cossie. & all the chavs ...... won no problem

On 22nd Jul, 2014 apbellamy said:
All being well I can get some miles on it now.


drive carefully andy *Yes*






John

User Avatar

10020 Posts
Member #: 1456
Mongo

Barnsley, South Flatcapshire

Nah drive recklessly!

If something is worth doing, it's worth doing half of.


apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

I think I'll take Steve's advise until it's run and things have finished falling off it...

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

*hehe!*


jbelanger

1267 Posts
Member #: 831
Post Whore

Montreal, Canada

You might be interested to know that all wideband O2 controllers measure Lambda and not AFR. Most of them do display AFR but that's with the assumption that 1.0 Lambda = 14.7 AFR

If you change fuel, you will still see 14.7 AFR at stoic no matter which fuel you use. To see the actual AFR for ethanol, methanol, LPG, CNG, ..., you need to change the calibration in your WBO2 controller and/or your ECU.

That's something to remember if you do go to a fuel other than gasoline (petrol). Otherwise you will end up with a fueling that is grossly out of tune.

Jean

http://www.jbperf.com/


Brett

User Avatar

9502 Posts
Member #: 1023
Post Whore

Doncaster, South Yorkshire

andy why not look in ugeo instructions? there is a table afr / lambda for each setting

Yes i moved to the darkside *happy*

Instagram @jdm_brett


Sprocket

User Avatar

11046 Posts
Member #: 965
Post Whore

Preston On The Brook

Lambda is the future. AFR is for pansies

*tongue* *wink**wink*

On 26th Oct, 2004 TurboDave16v said:
Is it A-Series only? I think it should be...
So when some joey comes on here about how his 16v turbo vauxhall is great compared to ours, he can be given the 'bird'...


On 26th Oct, 2004 Tom Fenton said:
Yep I agree with TD........


stevieturbo

3569 Posts
Member #: 655
Post Whore

Northern Ireland



On 22nd Jul, 2014 jbelanger said:
You might be interested to know that all wideband O2 controllers measure Lambda and not AFR. Most of them do display AFR but that's with the assumption that 1.0 Lambda = 14.7 AFR

If you change fuel, you will still see 14.7 AFR at stoic no matter which fuel you use. To see the actual AFR for ethanol, methanol, LPG, CNG, ..., you need to change the calibration in your WBO2 controller and/or your ECU.

That's something to remember if you do go to a fuel other than gasoline (petrol). Otherwise you will end up with a fueling that is grossly out of tune.

Jean


You only need to change the units if you want to see different units.

I'm content using petrol AFR's. I dont need to see a reduced resolution lambda value, nor any other scaling regardless of what fuel mix or type I'm using. The normal petrol AFR's is fine for me.

Just in exactly the same way some people are happy viewing a lambda based figure.

When people change to a different fuel scale/AFR...all the unit is doing is multiplying the lambda value you would see by the stioch value of the new fuel. So it really makes no difference.
It's purely personal preference as to what units you want to see

Too many get obsessed with having to view lambda, you have to recalibrate, you have to change units.

Bollox.

Edited by stevieturbo on 23rd Jul, 2014.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will


jbelanger

1267 Posts
Member #: 831
Post Whore

Montreal, Canada

On 23rd Jul, 2014 stevieturbo said:


On 22nd Jul, 2014 jbelanger said:
You might be interested to know that all wideband O2 controllers measure Lambda and not AFR. Most of them do display AFR but that's with the assumption that 1.0 Lambda = 14.7 AFR

If you change fuel, you will still see 14.7 AFR at stoic no matter which fuel you use. To see the actual AFR for ethanol, methanol, LPG, CNG, ..., you need to change the calibration in your WBO2 controller and/or your ECU.

That's something to remember if you do go to a fuel other than gasoline (petrol). Otherwise you will end up with a fueling that is grossly out of tune.

Jean


You only need to change the units if you want to see different units.

I'm content using petrol AFR's. I dont need to see a reduced resolution lambda value, nor any other scaling regardless of what fuel mix or type I'm using. The normal petrol AFR's is fine for me.

Just in exactly the same way some people are happy viewing a lambda based figure.

When people change to a different fuel scale/AFR...all the unit is doing is multiplying the lambda value you would see by the stioch value of the new fuel. So it really makes no difference.
It's purely personal preference as to what units you want to see

Too many get obsessed with having to view lambda, you have to recalibrate, you have to change units.

Bollox.


If you're comfortable doing this and understand what it is, fine. And that is what I would recommend people do so as to not mess up calibration somewhere and have inconsistent data.

But some people go to E85 and then they expect to see 9.7 AFR for a stoic mixture and they end with an absurdly rich mixture. They don't understand that they still need to target the same petrol AFR.

That was my main point. What you see is not an AFR value but Lambda multiplied by the theoretical 14.7 value (which is likely not the real AFR value for what you get from the pump in many places).

Jean

http://www.jbperf.com/


apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

On 22nd Jul, 2014 Brett said:
andy why not look in ugeo instructions? there is a table afr / lambda for each setting

Not on the instructions that came with the gauge, the ones on their website or the table they sent me. All 3 have volts and AFR only.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

*hehe!*


robert

User Avatar

6743 Posts
Member #: 828
Post Whore

uranus

yup I am setting my lpg on the sqrt ,and not bothering to reset the wb ,just tune to numbers I know leaving it on petrol setting.. although it does appear to be able to run 19 plus on cruise ,which I don't I think I could do on petrol.

Robert.


On 22nd Jul, 2014 jbelanger said:
You might be interested to know that all wideband O2 controllers measure Lambda and not AFR. Most of them do display AFR but that's with the assumption that 1.0 Lambda = 14.7 AFR

If you change fuel, you will still see 14.7 AFR at stoic no matter which fuel you use. To see the actual AFR for ethanol, methanol, LPG, CNG, ..., you need to change the calibration in your WBO2 controller and/or your ECU.

That's something to remember if you do go to a fuel other than gasoline (petrol). Otherwise you will end up with a fueling that is grossly out of tune.

Jean

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM


Brett

User Avatar

9502 Posts
Member #: 1023
Post Whore

Doncaster, South Yorkshire

its in my pdf *happy*


Attachments:

Edited by Brett on 23rd Jul, 2014.

Yes i moved to the darkside *happy*

Instagram @jdm_brett


Rod S

User Avatar

5988 Posts
Member #: 2024
Formally Retired

Rural Suffolk

Brett,

That datasheet must be for a different model, the AEM manual for Andy's model says "0.5 Vdc at 8.5:1 AFR to 4.5Vdc at 18.0:1 AFR" and that table doesn't go down to 8.5 in the AFR column.

Andy,

Easiest way is to put the formula from the AEM datasheet
http://aemelectronics.com/files/instructio...oline%20AFR.pdf
"AFR = 2.375(V) + 7.3125" into a spread sheet and divide the AFR column by 14.7

Here's a spreadsheet I previously made up for the 14point7 calibration, I've just changed the equation to the AEM formula.

It was rounded to two decimal places (because that's what I needed) so I've changed it to three as that's what Brett's has.


Attachments:

Edited by Rod S on 23rd Jul, 2014.

Schrödinger's cat - so which one am I ???


Brett

User Avatar

9502 Posts
Member #: 1023
Post Whore

Doncaster, South Yorkshire

yeah it is, its the data sheet for mine, it still shows afrs vs lambda

Yes i moved to the darkside *happy*

Instagram @jdm_brett


apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

Thanks Rod. I did the same thing last night and then scaled my table up to 16 rows (wouldn't go bigger). Will try it later on, maybe even go out for a spin.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

*hehe!*


stevieturbo

3569 Posts
Member #: 655
Post Whore

Northern Ireland




On 23rd Jul, 2014 robert said:
yup I am setting my lpg on the sqrt ,and not bothering to reset the wb ,just tune to numbers I know leaving it on petrol setting.. although it does appear to be able to run 19 plus on cruise ,which I don't I think I could do on petrol.

Robert.


On 22nd Jul, 2014 jbelanger said:
You might be interested to know that all wideband O2 controllers measure Lambda and not AFR. Most of them do display AFR but that's with the assumption that 1.0 Lambda = 14.7 AFR

If you change fuel, you will still see 14.7 AFR at stoic no matter which fuel you use. To see the actual AFR for ethanol, methanol, LPG, CNG, ..., you need to change the calibration in your WBO2 controller and/or your ECU.

That's something to remember if you do go to a fuel other than gasoline (petrol). Otherwise you will end up with a fueling that is grossly out of tune.

Jean


Some petrol engines will be quite happy running very lean at cruise, others wont. But as far as petrol is concerned, OEM dont do it purely for emissions reasons. 14.7 is just the cleanest average, and best for working with the cat.

But it's just a case of trial and error as to how lean you can run your engine without misfires etc. But sometimes even if it does run fine...it can be so lean it loses power, you end up using more throttle, more fuel despite same AFR.
So trying to run the leanest AFR, doesnt always mean it is the most fuel efficient.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will


e5tus

User Avatar

428 Posts
Member #: 10128
Senior Member

Dorset

Morning all,

Just looking through my car paperwork, the MOT gas analysis showed Lambda of 1.096 at exhaust exit, my AFR was showing 14.2 (measured in downpipe).

Knowing 14.7:1 = Lambda 1 for petrol, I’d have expected either the exhaust lambda to be 0.96 for AFR gauge showing 14.2, or AFR to show 16:1 against the lambda reading of 1.096.

Is the variance due to measurement location, wank calibration of the gas analyser, closed v open pipe?

If someone clever can tell me why, I’d be grateful. Ta


stevieturbo

3569 Posts
Member #: 655
Post Whore

Northern Ireland

lambda value on a gas analyser is an actual proper measurement. On a wideband, it is not.

for example, air leaks etc can skew the reading for a wideband sensor, not so much the gas analyser.

The above charts comparing the two, only work if the system is working 100% correctly. If there are any issues....there can and will be deviations.

Hence a proper gas analyser is always better here.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will


robert

User Avatar

6743 Posts
Member #: 828
Post Whore

uranus

e5, i have noticed on the dyno tailpipe reading being a little leaner than downpipe reading , i put thsi down to the ex gases changing a little as they complete burning as they go down the pipe .


regards
robert

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Home > Help Needed / General Tech Chat > Lambda v's AFR
Users viewing this thread: none. (+ 1 Guests)   Next ->
To post messages you must be logged in!
Username: Password:
Page: