Lambda
14-03-2007, 04:31 PM
#4
I've found that life I needed.. It's HERE!!
Thread Starter
Join Date: Jul 2004
Location: Grimsby
Posts: 1,267
Likes: 0
Received 0 Likes
on
0 Posts
okey doke,
Well i've just had an exhaust probe stuck in my exhaust pipe just to check the AFR (if thats the correct terminology) and on idle it settled at around lamda 2.0x then went to lamda 1.2x at 2500rpm.
Hope it makes a bit more sense now, or am I still talking drivel?
Well i've just had an exhaust probe stuck in my exhaust pipe just to check the AFR (if thats the correct terminology) and on idle it settled at around lamda 2.0x then went to lamda 1.2x at 2500rpm.
Hope it makes a bit more sense now, or am I still talking drivel?
14-03-2007, 04:41 PM
#5
BANNED
BANNED
iTrader: (1)
Join Date: Jul 2003
Location: Wiltshire
Posts: 12,483
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by foreigneRS
eh? course it does. it's an AFR of 28:1 rather than lambda = 1 of 14:1
that's very weak, i doubt it would run at such a weak mixture
that's very weak, i doubt it would run at such a weak mixture
14-03-2007, 05:00 PM
#7
is awesome
iTrader: (1)
Join Date: May 2005
Location: Chesham, Bucks
Posts: 4,802
Likes: 0
Received 0 Likes
on
0 Posts
I think he is talking about sausages.
1 sausage = 7.35:1 AFR
2 sausages = 14.7:1 AFR
1.2 sausages = 8.82:1 AFR
I prefer my sausages explanation but yes he is probably talking about CO %.
1 sausage = 7.35:1 AFR
2 sausages = 14.7:1 AFR
1.2 sausages = 8.82:1 AFR
Originally Posted by SECS
I reckon he is talking CO % NOT lambda.
Trending Topics
14-03-2007, 05:16 PM
#9
Come on you bunch of amateurs!! Give the guy some proper advice!!
It depends on what type of probe is used. If it's a proper Exhaust Gas Analyser, where the probe goes fairly deep into the tailpipe and you are seeing Lambda 2.0 then there is a problem.
However, if it isn't it could be as simple as a draft into the tailpipe affecting the reading. Especially if this is on a Dyno with the fan running.
An exhaust leak would also cause this.
It depends on what type of probe is used. If it's a proper Exhaust Gas Analyser, where the probe goes fairly deep into the tailpipe and you are seeing Lambda 2.0 then there is a problem.
However, if it isn't it could be as simple as a draft into the tailpipe affecting the reading. Especially if this is on a Dyno with the fan running.
An exhaust leak would also cause this.
14-03-2007, 05:26 PM
#10
I've found that life I needed.. It's HERE!!
Thread Starter
Join Date: Jul 2004
Location: Grimsby
Posts: 1,267
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the reply Christian. This was a probe placed only a few cm's into the tailpipe.
The guy who measured it (ex WRC Hyundai Technician) said we'll do a more comprehensive test once he's got a new clamp for the exhaust probe, on Tuesday of next week, so should hopefully see some results that are a bit more realistic.
The guy who measured it (ex WRC Hyundai Technician) said we'll do a more comprehensive test once he's got a new clamp for the exhaust probe, on Tuesday of next week, so should hopefully see some results that are a bit more realistic.
14-03-2007, 06:08 PM
#11
BANNED
BANNED
iTrader: (1)
Join Date: Jul 2003
Location: Wiltshire
Posts: 12,483
Likes: 0
Received 0 Likes
on
0 Posts
lead_foot PMSL
foreigneRS
Show me a petrol car running with a lambda of 2.0 and as there is
no mention of any bad running or incorrect measurement methods
all my answers are valid.
Christian and Beccy,
My advice given in simple terms of the question asked.
All makes me wonder why I even bother to help anyone anymore.
P.S. You are all coooooooooonts
foreigneRS
Show me a petrol car running with a lambda of 2.0 and as there is
no mention of any bad running or incorrect measurement methods
all my answers are valid.
Christian and Beccy,
My advice given in simple terms of the question asked.
All makes me wonder why I even bother to help anyone anymore.
P.S. You are all coooooooooonts
14-03-2007, 07:14 PM
#16
10K+ Poster!!
Originally Posted by SECS
foreigneRS
Show me a petrol car running with a lambda of 2.0 and as there is
no mention of any bad running or incorrect measurement methods
all my answers are valid.
All makes me wonder why I even bother to help anyone anymore.
P.S. You are all coooooooooonts
maybe?!
14-03-2007, 11:43 PM
#20
Why has nobody come up with what is probably, 95% certainly teh simplest and correct answer. 
This is about what you will get if you probe a car with a fully warmed up and active CATALYTIC CONVERTOR fitted.
Totally pointless reading a car with a catalyst unless its to ascertain that its working, which this one seems to be. lol
This is about what you will get if you probe a car with a fully warmed up and active CATALYTIC CONVERTOR fitted.
Totally pointless reading a car with a catalyst unless its to ascertain that its working, which this one seems to be. lol
14-03-2007, 11:46 PM
#21
Originally Posted by Rob84
The guy who measured it (ex WRC Hyundai Technician) said we'll do a more comprehensive test once he's got a new clamp for the exhaust probe,
Hmmm... missed this, so now i doubt this simple fact has been overlooked.
14-03-2007, 11:46 PM
#22
Professional Waffler
Originally Posted by Stu @ M Developments
Why has nobody come up with what is probably, 95% certainly the simplest and correct answer.
This is about what you will get if you probe a car with a fully warmed up and active CATALYTIC CONVERTOR fitted.
Totally pointless reading a car with a catalyst unless its to ascertain that its working, which this one seems to be. lol
This is about what you will get if you probe a car with a fully warmed up and active CATALYTIC CONVERTOR fitted.
Totally pointless reading a car with a catalyst unless its to ascertain that its working, which this one seems to be. lol
15-03-2007, 01:11 AM
#23
I've found that life I needed.. It's HERE!!
Thread Starter
Join Date: Jul 2004
Location: Grimsby
Posts: 1,267
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Stu @ M Developments
Originally Posted by Rob84
The guy who measured it (ex WRC Hyundai Technician) said we'll do a more comprehensive test once he's got a new clamp for the exhaust probe,
Hmmm... missed this, so now i doubt this simple fact has been overlooked.
15-03-2007, 07:43 AM
#24
Originally Posted by Rob84
Originally Posted by Stu @ M Developments
Originally Posted by Rob84
The guy who measured it (ex WRC Hyundai Technician) said we'll do a more comprehensive test once he's got a new clamp for the exhaust probe,
Hmmm... missed this, so now i doubt this simple fact has been overlooked.
Does the car have a catalyst fitted or not?
15-03-2007, 08:05 AM
#25
BANNED
BANNED
iTrader: (1)
Join Date: Jul 2003
Location: Wiltshire
Posts: 12,483
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Stu @ M Developments
Why has nobody come up with what is probably, 95% certainly the simplest and correct answer.
You have to admit, the initial question isnt exactly loaded with info.
15-03-2007, 08:50 AM
#26
I've found that life I needed.. It's HERE!!
Join Date: Jun 2003
Location: NWFP
Posts: 1,288
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Stu @ M Developments
Why has nobody come up with what is probably, 95% certainly the simplest and correct answer.
This is about what you will get if you probe a car with a fully warmed up and active CATALYTIC CONVERTOR fitted.
Totally pointless reading a car with a catalyst unless its to ascertain that its working, which this one seems to be. lol
This is about what you will get if you probe a car with a fully warmed up and active CATALYTIC CONVERTOR fitted.
Totally pointless reading a car with a catalyst unless its to ascertain that its working, which this one seems to be. lol
I didn't think catalytic converters changed the lambda reading, only removed the CO and HC
even if it had a huge exhaust leak,
there is not a gas analyser on the market that can read as far as lambda 2 .....
or is it different with oxygen sensors in the exhaust, does the cat remove oxygen?
I don't know about that, only about gas analysers..
(If so, then the idle lambda should be measured with a gas analyser not an oxygen sensor)
15-03-2007, 09:27 AM
#27
Originally Posted by the original
I didn't think catalytic converters changed the lambda reading, only removed the CO and HC
there is not a gas analyser on the market that can read as far as lambda 2 .....
A decent one like mine will read down to lambda 10.
http://www.labcell.com/product.asp?id=17&pr=46
(If so, then the idle lambda should be measured with a gas analyser not an oxygen sensor)
15-03-2007, 09:51 AM
#31
I've found that life I needed.. It's HERE!!
Join Date: Jun 2003
Location: NWFP
Posts: 1,288
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Stu @ M Developments
Originally Posted by the original
I didn't think catalytic converters changed the lambda reading, only removed the CO and HC
there is not a gas analyser on the market that can read as far as lambda 2 .....
A decent one like mine will read down to lambda 10.
http://www.labcell.com/product.asp?id=17&pr=46
(If so, then the idle lambda should be measured with a gas analyser not an oxygen sensor)
a true gas analyser will measure the same afr after a cat. as what's produced in the engine
I thought they may have been using a gas analyser (like in an Mot station or most garages) but I guess it wasn't, just a lambda gauge
I think Alex F understands what I'm getting at
15-03-2007, 10:00 AM
#34
10K+ Poster!!
Just for a sake of somthing to do I'll waffel on about how cats work!
The process that a catalyst uses is based on 2 opposite chemical processes;
Oxidation- where a substance combines with oxygen
Reduction- where a substance releases oxygen.
The use of precious metals; platinum, rhodium and palladium convert the pollutants into non toxic gases.
3 way catalytic converters are the most common and fitted to all new petrol engines.
The gasses effected by the cat are CO, NOx and HC.
You get rid of CO by ADDING O2 (oxidation)
You get rid of HC by ADDING O2 (oxidation)
But of these conditions you achive by running the engine a tinyt bit lean (excess o2 in the exhaust gas).
NOx you get rid of by SUBTRACTING 02 (reduction).
To achieve this the exhuast needs to be low in O2, so you run the engine slightly rich.
This is why is you scope a lambda sensor you get a trace like this....
http://www.picotech.com/auto/wavefor..._zirconia.html
The process that a catalyst uses is based on 2 opposite chemical processes;
Oxidation- where a substance combines with oxygen
Reduction- where a substance releases oxygen.
The use of precious metals; platinum, rhodium and palladium convert the pollutants into non toxic gases.
3 way catalytic converters are the most common and fitted to all new petrol engines.
The gasses effected by the cat are CO, NOx and HC.
You get rid of CO by ADDING O2 (oxidation)
You get rid of HC by ADDING O2 (oxidation)
But of these conditions you achive by running the engine a tinyt bit lean (excess o2 in the exhaust gas).
NOx you get rid of by SUBTRACTING 02 (reduction).
To achieve this the exhuast needs to be low in O2, so you run the engine slightly rich.
This is why is you scope a lambda sensor you get a trace like this....
http://www.picotech.com/auto/wavefor..._zirconia.html
15-03-2007, 10:01 AM
#35
Originally Posted by the original
[Stu that's what I'm saying, what you have is not a gas analyser
a true gas analyser will measure the same afr after a cat. as what's produced in the engine
a true gas analyser will measure the same afr after a cat. as what's produced in the engine
I disagree, a normal MOT gas analyser wont read the same wether tested before or after a catalyst at all, sadly i dont have all day to argue this point as i am rammed busy, but i am quite sure the argument will rage on.
15-03-2007, 11:27 AM
#38
10K+ Poster!!
Originally Posted by SECS
AlexF,
Yes but ONLY after the cat
Yes but ONLY after the cat
As an AFR is lamdba 2 about 30:1 ??
Alex
15-03-2007, 11:36 AM
#39
BANNED
BANNED
iTrader: (1)
Join Date: Jul 2003
Location: Wiltshire
Posts: 12,483
Likes: 0
Received 0 Likes
on
0 Posts
AlexF,
As I said above, the original question didnt exactly have all the info and I and
others made many assumptions.
A petrol engine wont run on a lambda of 2.0 which was my original point.
The fact a cat can alter the output exhaust and that is measured is
another point entirely.
Talk about a can of worms
As I said above, the original question didnt exactly have all the info and I and
others made many assumptions.
A petrol engine wont run on a lambda of 2.0 which was my original point.
The fact a cat can alter the output exhaust and that is measured is
another point entirely.
Talk about a can of worms
15-03-2007, 12:23 PM
#40
Testing the future
SECS there are petrol engines that will run on an average mixture of lambda = 2 and have been for many years
just that they normally have a localised mixture at the spark plug closer to 1
just that they normally have a localised mixture at the spark plug closer to 1