Auto Tune, how does it work ?
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Cruiser
Joined: Aug 2015
Posts: 113
Likes: 4
From: Dartmouth, Devon, UK
Hi Jamie
But surely if it makes an educated guess, the Auto Tune will not add anything ? Other than helping the guess at 14.6 which is know and works well in closed loop anyway ?
Surely the best way is to to dyno one, and copy that map ?
Dave
But surely if it makes an educated guess, the Auto Tune will not add anything ? Other than helping the guess at 14.6 which is know and works well in closed loop anyway ?
Surely the best way is to to dyno one, and copy that map ?
Dave
Not exactly, auto tune takes corrections populated by the closed loop integrator and re-writes the VE tables rather than use them as a multipler and block learn. There is a big difference between closed loop having to reach out and correct a mixture that is for example 20% lean vs using auto tune to put the corrections right in the VE tables. Auto tune Basic with Power Vision can populate corrections for the entire VE table, however I generally use the factory O2's up to about 80Kpa.
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Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
to provide a bit more information, here is an example of a user I recently worked with on another forum that had less than desirable results after he had his bike dyno tuned. His map was all jacked up from the dyno tune so I had him start over with a slightly revised version of the original supplied FM map. He worked on the tuning thruout the week, this consisted of several seperate occasions of running three, 20 minute sessions using the Auto Tune basic application. Between each session he exported the learned corrections and updated the tune for the next session. After each tuning session we had him submit the new tune that was populated as well as a datalog of mixed riding running off the new tune for review. I made some adjustments along the way as well based on patterns etc..
Below are a few MLV screenshots of the latest log he provided, closed loop is averaging within about 1% correction for both CLI (short term) and AFF (long term) multipliers.
Below are a few MLV screenshots of the latest log he provided, closed loop is averaging within about 1% correction for both CLI (short term) and AFF (long term) multipliers.
All depends on the specific bike & combination, however in most cases we fall back on our standard AF/Lambda tables and modify as necessary. Closed loop is also more robust on the late model CANbus bikes for sure. There are certainly exceptions; bikes with aging O2 sensors, less than desirable exhaust or engine combinations, and as you know earlier closed loop Sportsters are another good example. It all comes down to knowing what to do with the data whether you are using auto tune or otherwise.
Correct, you want CLI and AFF values to be as close to 1.00 as possible as they are both individual multipliers of VE, these values show us the specific amount the ECM has to lean on the O2 sensors for fuel correction vs calculated fuel delivery. The equation for closed loop is CLI X AFF X VE = New VE. For example a value of .89 would represent the ECM is correcting a mixture that is 11% rich, where a value of 1.15 would be a lean correction of 15%. CLI is live short term correction, AFF is stored adaptive block learn.
Below is an example of a bike that needs some tuning, note the CLI corrections especially on the rear cylinder which are 15% or better to the lean side.
Below is an example of a bike that needs some tuning, note the CLI corrections especially on the rear cylinder which are 15% or better to the lean side.
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From: Snow Hill, NC
Stayed on the phone with a laptop by the bike with Dynojet on the phone,twice, they both times said everything seemed fine, I was about to leave for a trip to Canada on the bike so I just put the Fuelmoto nap back in there and have not look back since...
I get about 39 mpg avg and throttle response when I want it...no more complaints.
I get about 39 mpg avg and throttle response when I want it...no more complaints.
Road Master
Joined: Mar 2007
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Here is a speech I did at a Megasquirt Meet with the matching PDF regarding understanding MLV data. This may help people understand some of these screen shots.
This is the matching PDF screen shots.
http://www.nbs-stl.com/MLVDemo/MLVHD%20Demo.pdf
Andy
This is the matching PDF screen shots.
http://www.nbs-stl.com/MLVDemo/MLVHD%20Demo.pdf
Andy