Lambda to Air Fuel Ratio Table

[Glenn Butcher]

Hi all,

Thought I would post this up for reference, and stick the thread.  If you have anything to add - please do so.

Lambda to   Air Fuel Ratio Table:

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

	Lambda	Air Fuel Ratio
Petrol	Alcohol (Methanol)	LPG	Diesel
RICH         END OF SCALE	0.70	10.3	4.5	10.9	10.2
	0.75	11.0	4.8	11.6	10.9
0.80	11.8	5.1	12.4	11.6
0.85	12.5	5.4	13.2	12.3
0.90	13.2	5.8	14.0	13.1
0.95	14.0	6.1	14.7	13.8
1.00	14.7	6.4	15.5	14.5
1.05	15.4	6.7	16.3	15.2
1.10	16.2	7.0	17.1	16.0
1.15	16.9	7.4	17.8	16.7
1.20	17.6	7.7	18.6	17.4
1.25	18.4	8.0	19.4	18.1
1.30	19.1	8.3	20.2	18.9
1.35	19.8	8.6	20.9	19.6
1.40	20.6	9.0	21.7	20.3
1.45	21.3	9.3	22.5	21.0
1.50	22.1	9.6	23.3	21.8
1.55	22.8	9.9	24.0	22.5
LEAN         END OF SCALE	1.60	23.5	10.2	24.8	23.2

[bill shurvinton]

Please define \'alcohol\' Methanol and ethanol have different stoich AFRs

[Glenn Butcher]

Hmmm, it was from a table I was sent on fax - I\'ll find out Bill.  Actually I may add the two.

[bill shurvinton]

I have the figures at home so I\'ll post them tonight.

[Glenn Butcher]

Ta mate - I\'ve been looking around for them but cannot find at the moment.

[Carl]

Hi Glenn and Bill,
The alcohol in this case is fior Methanol.
If it was nitromethane then it would be 3to1 ratio of fuel to air for Stoichiometric and Methanol is around 7 to 1.
Kind regards
Carl

[Glenn Butcher]

Thanks Carl,  I literally just got the answer back also.  

[bill shurvinton]

Couldn\'t extract the FJO table from pdf to post a double check, but examining them there is at worst a 0.2 difference.

I have a minor problem with this table thinking more about it.

Basically a wideband will measure stoich for any fuel no problems.
However once you are rich or lean of stoich you are measuring a different set of combustion products so a simple linear shift like this WILL give the wrong answer.

Bill

P.S. Stoich for ethanol is 9:1. Worth pointing out that ethanol is a whole lot cheaper and more readily available in this country.

Neat toluene on the other hand......:-)

[yonner]

what ratio do you want in a fast street car?? im guesing 9:1 coz i read thats waht the stock is