lambda sond and diy lambda meter

[paso750]

as as reference a (my) Paso header:



PS: the adapter on the side of the front header tube is not original. That part was welded in so for proper engine/carb adjustment a lambda sond can be used. Further advantage is that with a mobile lambda meter you can also check when riding. The adapter costs like €15-20 or so plus welding. Ducati sells it as a single part.

aftermarket companies like this one sell it for € 7.50 ($11) but w/o the short bolt and copper gasket to close it.

[paso750]

a few years ago there was an article on two sites of silent-hektik.com about lambda meters. Unluckily they are long down.
I had saved the pages but they are in german and unluckily missing all the pictures. Anyway this may be interesting for some of you:


Here a fast translation (modified auto translation):

title: a lambda-meter almost for free

The lambda sond (probe)
For the tuning useful Lambda probes cost around 300, - to 400, - DM ($ 140-190) ea. in a shop. If one does not necessarily need a broadband measuring instrument, but only wants to check (measure) one or two work areas of the engine, also an inexpensive probe from a passenger car can do a good job. Used probes can originate from accidented cars from a recycler. Usually only 30, - to 50, - DM ( $14-24) are due. In any case it should be a four-wire probe. The manufacturer is unimportant. Two connectors are the heating, the two others are the signal. The connections should be checked according to vehicle wiring diagram.

The indicator
For the display of the probe signal an inexpensive circuit analyzer (multi-meter) from an electronic shop will do. It should have a DC voltage measuring range of 0-2V. If the display is analogue or digital is not important. With analogues (with needle) however the intermediate values can be determined more easily. One already gets such a circuit analyzer for 20,- DM ($ 8,50).

The assembly
For the assembly of the probe to the exhaust manifolds two threaded collars are needed. Each is welded or hardsoldered approx. 50cm after the exhaust valve (logically a hole has to be drilled in the headers). A version out of stainless steel does not rust later. The sleeves an be bougt from many dealers in stock; or manufactures (Ducati sells `em incl. a screw to tap the hole), according to the accompanying sketch. (price is around DM 50,- ($24) for 2)
see here:

http://www.silent-hektik.com/page75.html (not existing anymore)

The equalizing (how to use the multi-meter as lambda-meter)
The equalizing of the "Lambdameter" is necessary, so that the result of measurement has also a predicate. For it find a AU measuring place (at many gas stations and workshops). (ask a garage who does emmision tests - AU btw. is the german emmission test)
With the engine at operating temperature at idle adjust the mixture adjusting screw on first 0,8La and write down the voltage from the digital circuit analyzer (multi-meter) you`ve connected to the lambda sond or make a mark if you use an instrument with a scale line. Then follows 0,85La, then 0,9La, then 0,95La. More values are not needed. You have now created your own reliable lambda-meter.
The result will be something like this:


The tuning
The global-tuning takes place basically in driving, because on a test stand only the full load (full power) area is tuned.
An engine has it`s max. performance with approx. 0,88La to 0,90La (rich mixture). The engine has smallest consumption with still acceptable running culture (smoothness) with approx. 0,90La to 0,95La. When accelerating it should be 0,8La, in order to receive a spontaneous acceleration.
With Lambda 1.0 to 1.1 the engine has the smallest pollutant proportions with smallest gasoline consumption, but also a smaller performance with increased gasoline consumption, with increased engine temperature and particularly with miserable runnig culture. At values under 0,7La (very rich) or over 1,2La (very lean) usually the ignition boundary is achieved; the engine stutters.

Sorry for the bad automatic translation, but I don`t have any more time !
I think this is a great way to fiddle around a bit on the carburation by yourself with only a little bit of investment. Btw. Micron sells a small meter + lambda-sond for $ 190 or so.

---------------------------------------------------------------------------

http://www.silent-hektik.com/page74.html (not existing anymore)

for the graphics on the page:
P = power
b = fuel consumption
Emissionen = emissions
Lambdaspannung = lambda voltage

The theory
For burnung a part of gasoline 14.7 parts of air are needed, to receive a theoretically full-coming burn. The relation of the value of supplied air to the theoretically needed air is the lambda value:

In the theory optimally:
14.7 / 14.7 = 1.00 Lambda

Too little air:
13.0 / 14.7 = 0.88 La - > rich

Too much air:
17.0 / 14.7 = 1.16 La - > lean

From the right diagram is evident, that max. performance and minimum consumption is not at the same time possible, even if some tuners say this.
All the same whether carburetors or injection, when tuning a compromise must be found. This is usually situated with Lambda 0.88 to 0,92. The Lamda value is measured with the help of a Lambda probe. This zirconium dioxide probe (on the right) supplies a voltage, which can be analysed by electronics.
A typical probe voltage is to be seen in the lower diagram.

The tuning
Per HP and hour an Otto engine needs 250 gram gasoline (330mL) to unfold the max. performance. An Otto engine has the max. performance with approx. 0,85La to 0,90La (rich mixture).


G.

[paso750]

here a german page with diy plans for a lambda indicator you can mount on the bike.
http://www.taunus-biker.de/~mdvp/Lambda/Lambda.html

here some english pages
http://www.redline.lt/magazine/spec-fea ... icle/17/1/
http://www.pelicanparts.com/techarticle ... onitor.htm

and here for the ones who want to go more into detail:
http://lambdapower.co.uk/technotes/techindex.asp


... the usage of lambda sonds is not limited to vehicles with electronic fuel injection systems (and catalytic converters)

[ducapaso]

Per HP and hour an Otto engine needs 250 gram gasoline (330mL) to unfold the max. performance. An Otto engine has the max. performance with approx. 0,85La to 0,90La (rich mixture).

Theorically it's true, but carb engines are setted about <3.50La also for periodical tests, While E.F.I. engines are usually required to run at < 1.00La.
This is because of incomplete "polverization" of gasoline fog in the air.
A leaner mixture can damage valve seats and piston rings

[paso750]

3.50 La would mean its 3,5x leaner !


taken from the link posted before:

For perfect, efficient combustion to occur, the ratio of air to fuel is 14.7 to 1. That is 14.7 parts air to one part fuel. The lambda sensor is fundamentally important in allowing the ECU to maintain this ratio, as the sensor is designed to detect this crossover point from below 14.7:1 - ie. too much fuel = mixture too rich, to above 14.7:1 - ie. too much air = mixture too weak. We denote this with the Greek letter "L" or "lambda". The letter "lambda" represents a quantity called the 'excess air factor'. The perfect ratio is Lambda =1.0. The scientific name for this perfect ratio is the 'Stoichiometric Ratio' .

If there is too little air, the mixture is too rich, and there will be fuel left over after combustion. This pollutes the environment. If there is an excess of air the mixture is too lean, and more NOx pollutants are produced. We will see more about the main pollutant groups later. The actual amount of air that the engine can suck in at any time depends upon many things, for example the altitude, the air temperature, the engine temperature, the barometric (atmospheric) pressure, the engine load, and so on.

[paso750]

with 3,5 you don`t by mistake mean % CO ?! (that should be around 4,5%)

[Tamburinifan]

Very interesting, thx f sharing!

If one does not necessarily need a broadband measuring instrument, but only wants to check (measure) one or two work areas of the engine, also an inexpensive probe from a passenger car can do a good job.

Could you explain that a bit more, how do you use it to measure more
than idle?

[ducapaso]

with 3,5 you don`t by mistake mean % CO ?! (that should be around 4,5%)

No, you're asked for a leaner ratio than 4.5% but a in good E.F.I. engine you can measure also 1% before the catalizer. They've also a better design of combustion chamber, and a PERFECT injection and ignition mapping!... miracles of CAD/CAM

[paso750]

Don`t mix La with %CO.

I sent you a PM.

G.

[Finnpaso]

I have put to both my Pasos 2 lamda sonds and led 2-channel meters. Pitty, that wide range lamdas are sooo expensive, so ran with simple 1 wire sonds. I have welded connections to both front nad rear headers. Display is up from dash, but under front fairing in middle just up from clock. Just thinking to weld connections also to ST2 headers, if need to tune in dyno... I put soon to my ST2 CF open Ducati Performance pipes and FIM chip...and surely Z = 14 front sprocket.... later Öhlins front springs(waiting allready in garrage)

But have to find, OR make display for ST2 first. Doeas anybody know, how much they coast in EU area internet shops??? Mr "G", You surely know more, cause you are intrested of this...

[Finnpaso]

I bought already electrical parts and very small box to make that 10 LED meter with 2 channels and parts coast 14,80€

[paso750]

Antti,

sonds at good price can be found here:

http://www.lambdasonden.de/cgi-bin/base ... kel|detail

instrument displays:
http://cgi.ebay.de/LAMBDA-ANZEIGE-Lambd ... dZViewItem

$139 display only ($190 as kit incl. sond)
http://www.splitsec.com/
http://www.splitsec.com/products/airfuelmeter.htm

round displays:
http://shop.wiltec.info/tabshop_s/untit ... 41340.html
http://www.yatego.com/wildanger/p,430c6 ... io-display
http://shop.wiltec.info/tabshop_s/smoke ... 41341.html

complete system:
http://www.lambdatester.de/bild_set_lt20.htm

G.

[Tamburinifan]

All very interesting & thx f sharing!

But still wondering how use ful narrowband sensors are.
Could you f e measure 1/4 throttle/4500 RPM accurately if you
hold that steady for a minute?
How do you use it above idle?

[Finnpaso]

Thanks, G-man. As you know, i send reply to Your PM to me.... I dont need VERY accurate meter, but i build such, that i know, that nothing is "totally wrong" in my injection/carburation. That 2 channel 10 LED display is enough good to me. If i need accurate meter, my Ducati friend have one very good instrument for that...