Lamda

[Txsupra]

Who uses it and why?

 

[TurboStreetCar]

Stock TCCS, closed loop mixture control.

 

[Txsupra]

Sorry I was thinking more along the lines of after market wide band style. In conjunction with stand alone setups

 

[suprarx7nut]

I used lambda in Calculus and Differential Equations every now and then, but I found alpha, beta and gamma to be appropriate more often.

 

[foreverpsycotic]

Sorry I was thinking more along the lines of after market wide band style. In conjunction with stand alone setups

Most if not all widebands read lamda, they just do not display it.

 

[isnms]

Search for lambda and you'll get more results than lamda

14.7 is stoich for gasoline, numbers below that are rich number above that are lean. You may hear another term, the greek letter lambda. no matter what fuel you are running 1 lambda is stoich. the 14.7 AFR means in order to achieve 1 lambda in a vaccum, you need 14.7 parts air to one part fuel. We dont drive in a vaccum so you want richer numbers to be on the safe side. (keeps temps down, and prevent many problems) your so your idle is a little lean 14.8/14.7=1.007 lambda, around 14.0 would be ideal or .952 lambda. At WOT your 10.0 is a little rich. (10.0/14.7=.68 lambda) ideal safe range would be 10.5 if your running high boost, to 11.5 for lower boost setting (.714-782 lambda.) Lambda is important to understand because 1lambda is always stoich no matter what fuel you use 14.7 is only stoich using pure gasoline.
If you are modding your supra or planning on turning up your boost, its time to start researching fuel controllers. if your just running it at stock boost, your numbers are probably fine, just a little rich at wot, but the worst that can do is leave some black smoke on your rear bumper.

Too add

where does AFR come from? AFR is a derivative of Lambda.

lambda= actual AFR/stioch afr.

using gasoline/petrol.

lambda = 11.5 AFR / 14.7 AFR = Lambda .78.

So at stioch for Petrol/Gasoline

lambda = 14.7 AFR / 14.7 = Lambda 1

Methanol 6.4 AFR/ 6.4 AFR = Lambda 1
LPG 15.5 AFR / 15.5 AFR = Lambda 1
NitroMethane 1.7 AFR / 1.7 AFR = Lambda 1

everyone see a pattern? Regardless of fuel. At stoichiometry, Lambda will ALWAYS equal 1. Hence why you can tune any fuel using any familiar AFR scale. Like the Gasoline/Petrol AFR scale to tune E-85 or LPG.

 

[Txsupra]

My PLX Device can display in Lamda..<< and thats how its spelled in their hand book that comes with it.

I was just trying to figure out why anyone would use the Lambda option for any reason.

 

[isnms]

Just cause they spelled it wrong doesn't mean you have to
[noparse]http://dictionary.reference.com/browse/lamda[/noparse] = no dictionary results

I provided the information I found.

 

[Txsupra]

This forum would be a lot better if people would post more useful information instead of looking for the next reason to break someones balls or flame someone to death. *not to say that its not one if not the most useful forum out there* Just sayin

 

[isnms]

I posted useful information. The reason you didn't find it yourself searching is because you spelled it wrong. Simply suggested if you spelled it right you might find more info and then I posted the pertinent info.

hth

 

[Txsupra]

You can search all you want. Im trying to find out why someone would use a lambda setting. Not what it is. Im well aware of what Lambda is.

 

[isnms]

Using different fuels ..... kind of explains it in the info I posted.

 

[TurboStreetCar]

Noone does. AFR is easier to use, lambda is just another measurement.

Its like asking who uses KPA for boost rather the PSI, or vice versa.

 

[IJ.]

AFR is easier to get your head around as it has a wider scale, ECU's read in Lambda.

I used to run a Powerdex that read in AFR and my MoTeC dash set to Lambda, it was confusing to say the least so I had the Powerdex input to the ECU and the MoTeC convert Lambda to AFR and both displayed on the Dash.

Lambda AFR

0.787 11.57

0.889 13.07

1.000 14.70

1.121 16.48

 

[Txsupra]

Thank you