Lambda-Values
.....and what counts


There should more than enough to read about that Subject - on the Internet and probably thousands of Books .

As I've heard from a couple of Engine Tuners with their Dynojets and over here, and accordingly their Dynoruns - it is often not the same how a Bike runs adjusted on the dyno , or adjusted ( by sentiment or logging ) in real Life on track or on road. Adjustments which sometimes on the Dyno gives good results don't run very well on the street , and reverse, some Bikes which are very well adjusted " Live" on track or road do not draw a good line on the dyno.

Some good Engine Tuners with their Dynos may know the Difference between simulated and real Conditions, and may do some little Corrections reg. their "Mapping" due to their long experience with dynos and real world riding, some maybe don't. As there is no proof of their work possible in the real world, so on track or road, we do have to trust that paper given from a simulation. We've got the A/F Ratio black on white ...admittedly most do have that ratio only for 100% throttle, so the A/F Ratio for 1-99% Throttle is still hidden on the dark Side of the moon.

But lets do a check, what different kinds of real world riding Situations we have :

 

...... so if you would like to extract all the possible combinations I think no calculator would be able to express the Number .
Accordingly a proper Dyno-Tuning would take a infinite Time. Thanks god the Engine will quit Life very early, otherwise we'd have to wait a long Time.

A Dyno Adjustment is a good Base, like a good bread - but a good Burger needs something between the bread half's .

Since 7 years now I'm recording my Mixture, all the values from road or track. Since 5 years I'm analyzing the real Life mixture-recordings from customers, and also ( if required ) do some " online tuning " regarding their Mapping . At the beginning I did the same rookie mistake as maybe everyone has done it when he started with adjustments of A/F - I focused myself on 100% Throttle.

But very soon then I was shocked:
I've opened a screen ( Motec ) with my Statistics from track ... and I'm not such a worse rider ...and there was it, so to speak also black on white - the usage of 100% throttle on track ( with a Powerful Twin or 1000CC I4 ) with a average skilled rider was from approx 1-4.5 % . Normal Road riding ( no highways) from door to door has a full throttle partition of maybe less than 1% .

The same it is if you could check the Statistics of usage of the RPM range. Talking about powerful Bikes with average skilled Riders on track you're using most often the 2/3 Section of the available RPM-Bandwidth. The usage of the last 1000 RPM before the Limiter also is approx 1-4 %.

So the real Life where the Music plays is somewhere else.
A very important real life feature is how the throttle response after reaching the apex is , so the "back on throttle " behavior of the Bike. That's the TP from 0-5%, which really needs some fine adjustment, as usually you're at the Border of grip then, and you don't need a hard biting or spitting Engine especially in this Situation. Next then you've got the smooth Acceleration out of the corner, where you open throttle relatively slowly, and that makes a huge Partition in the Statistics of TP Positions usage, it's ~ 20 to 45% Throttle.
From 50-100% you open throttle with a higher Throttle-Acceleration, because from a certain level of " remaining lean angle" you're more confident regarding the grip.

So for one day on track ( ~ 2002) I focused myself only on the A/F Ratio Adjustment of the 20-40% Throttle Section (whole RPM Bandwidth), and the result was incredible. The Acceleration out of the corner was much much stronger, this was already slightly noticeable at the first Adjustments, but in end my RC51 had enormous Torque at Acceleration out of the corner.

I cannot really say that this measurement brought me to the bright Side of the moon, as from then I really feared to open throttle due to the Power which I've been able to set free, but at least I got a distinct experience about fine tuning.

But there is a tipping point for everyone in the world, where more Power leads in worse Laptimes ( lets say without TC):
 

Engine Tuning then leads either then in high- or lowsiding, or at least the first felt tendency of that, which furthermore for some leads into opening the throttle with less Acceleration then before they had tuned the Engine.
But there are different measurements to handle that:

But not no go too much OT:
All the different conditions which affects the A/F Ratio while we ride need a Lambda Monitoring, and I think too - a automatically "fine adjustment" , as noone can program so many "look-up" tables ( and their conjunction too ) as we need to have optimal A/F ratios in every Situation.
We still see Lambda Probes on each header on a lot of GP Bikes ( and they should have access to dyno I think), I mean for monitoring and control and improvement of Engine behavior , or throttle response.

 

So then if the A/F Ratio is perfect- a Fuel Table looks like this :