SERT - Setting VE- VE vs VE-New

[pauly]

G'day all,

SERT 477.
07 Softail

Think I'm missing something so thought I'd better ask before I screw things up - It's about setting the VE after some data runs.
The SERT Data Mode program has VE Front, & VE rear, which is a direct read of the tables (setup in tuning mode) value. There's also 'VE New Front' & 'VE New Rear' which (and here go my assumptions) seems to be a corrected value for the conditions at hand. Now - to the question - Lets talk single cells for the time being -

If my RPM is 2500, Throttle position is 100%, 'VE Front' is 116%, and the 'VEW New Front' is 105% - Would I be wise to look at updating the VE values to match the 'VE New' values?

I've done a few data runs now, and want to start looking at the data and improving the tune.

Thanks - Hope I've been clear
Pauly

[ViennaHog]

That is at least correct in the theory. Not sure if throttle position, rpm and corresponding VE data are perfectly timed.

[pauly]

Thanks Viennahog,

Yeah - I know what you mean. My intention is to continue doing data runs and eventually get the VE close to the New Ve settings, and the ignition timing close to (but not) retarding. Feel a bit retarding meself!

[Steve Cole]

Under WOT conditions New VE is not correct for what needs to be in the VE tables. As a matter of fact the only time NEw VE is any good is during limited conditions. Some are part throttle and cruise steady state. It must alaso not be in several operating conditions like PE, AE, DE, open loop and several other things can cause the data to be invalid. This is just why we no longer gather this data to display it. When used properly it is a good indication of what is going on but do not think it is a proper correction for tuning most of the time.

[pauly]

G'day Steve,

Thanks for that - very informative.. So how 'bout I do a number of other runs 'cruising'. For example - Throttle at 50%  - Then use those New VEs?

Regards
Pauly

[Steve Cole]

Understand the the VE new is a computed value from the ECM. What this means is that at best it is a good indication under the proper conditions. It is never the value for anyone cell itself. The microprocessor uses a weighted average of the surround cells to get a proper VE value. With this in mind you can use it but you will find it is always changing, so it all depends on how accurate you want to be. You need to look at the other data and sort out when the value can/should be used. Sorry there is no straight forward answer but it just isn't that simple.

[TXP]

Basically what I see with VE vs New VE is that it's a very useful tool for dialing in the cruise areas only on the Dyno under a light load. You mentioned 50% throttle. I doubt the VE vs New VE would ever be correct at this Throttle Position. You will notice your throttle position @ cruise will almost always be betwwen 5 and 15 % throttle. This is where watching The new VE and O2 integrator information is most accurate and most useful. As far as single cells go, you should watch your data as for example the TP will commonly read 7-9%. This means the ECM is extrapulating information from the closest surronding cells. Tuning is a trial and error process. As Steve said, be careful about assuming the New VE tables are always correct because they are not. They are pretty useful at light load after the bike has stabilized in a particular TP area under light load.

[FLTRI]

Basically what I see with VE vs New VE is that it's a very useful tool for dialing in the cruise areas only on the Dyno under a light load. You mentioned 50% throttle. I doubt the VE vs New VE would ever be correct at this Throttle Position. You will notice your throttle position @ cruise will almost always be betwwen 5 and 15 % throttle. This is where watching The new VE and O2 integrator information is most accurate and most useful. As far as single cells go, you should watch your data as for example the TP will commonly read 7-9%. This means the ECM is extrapulating information from the closest surronding cells. Tuning is a trial and error process. As Steve said, be careful about assuming the New VE tables are always correct because they are not. They are pretty useful at light load after the bike has stabilized in a particular TP area under light load.

[Rider57]

Understand the the VE new is a computed value from the ECM. What this means is that at best it is a good indication under the proper conditions. It is never the value for anyone cell itself. The microprocessor uses a weighted average of the surround cells to get a proper VE value. With this in mind you can use it but you will find it is always changing, so it all depends on how accurate you want to be. You need to look at the other data and sort out when the value can/should be used. Sorry there is no straight forward answer but it just isn't that simple.

According to the engineers in the lab here, that is the best answer given and possibly the only best one that could be given.