A/F on Dyno

[fat frank]

Just curious as to why my A/f shows so much difference in different gears. I tuned in 4th, did a pull in 5th and 3rd and they are all different. Can't seem to get it all to come together. What am I missing here. Bike is running awesome with plenty of power.
Just can't understand why they aren't all the same. My timing is from Wayne at Tuneboy from Matty's tune. Secondaries removed and 100% open, rev limiter set at 6700 rpm, speed limiter maxed out, O2 removed, triple 3780's with STS mounted in end of #2 filter and Jardines. 156RWHP and 160.5 torque.
We have been using a particular honda dealer's dyno. Think I may try another dyno. What could be causing this or is it normal.
A little advice would be welcome from the guys in the know. Don't want to hurt the bike. Wondering if the PCV might work to help this in conjunction with the Tuneboy.
Thanks in advance.

 

[Power-Tripp]

FIRST, realize that there is considerably lag time between when the exhaust gases leave the exhaust port and when they are detected by a Lambda sensor. This can be anywhere from 1000-2000 rpm of lag on an inertia dyno in fast accelerating bikes in top gear. This will be amplified in lower gears.

Second, the amount of time spent at a particular engine speed changes, as does the load, in different gears. This means the load and acceleration rate changes, combustion and engine temps change, and this means that the engine wants different fueling and ignition advance in first gear, compared to top gear. Even more so, when the pull is not started at the same engine and oil temps.

Third, different Lambda sensors, on different dynos, will read differently. Many shops do not know how, or have the equipment needed, to test Lambda sensors, or to know when they are in need of replacement.

And finally, the further the mapping is from optimized, the more difference you will see in Lambda/AFR readings run to run, gear to gear. Especially in how the acceleration enrichment occurs, and MAP table mapping.

I hope this helps.

 

[borntoride63]

boy I wish I lived closer to you! So you could dial in my bike!