new firmware releases

[AVP]

Gints,
how many of your bins on lamda control will you have to use in order to have a nice and stable idle that works 99% of the time and is not relying on ignition timing only?

Lamda as a table is so small that gives you less opportunity to fine tune something that most tuners have for granted.Thats why i suggested something like that.

on earlier versions where tables were 14x16 there was no problem since you have the flexibility to use many different bins from such a big table.But now, if half your lamda table is given to control idle, how will you have enough bins for cruising and <100kpa fine tuning?

On the other hand, in spark table you end up using at least 4-6 lines dealing with kpa values that are making that table even less accurate.I know vems is interpolating, but depending on cams and setup as gunnar says you may require as many bins as possible to make use of them.

Since ideal 'stock' like idle is possible with VEMS and we have the developers reading, i thought that a suggestion like that may make things more accurate.

[gunni]

a large lambda table is definitely not needed.

as you only use so many values, from 1.05 down to maybe 0.8 or so and usually in 0.5 steps, so total 6 steps.
0.8 , 0.85 , 0.9 , 0.95 , 1.0 , 1.05

And alot of the rpm´s and kpa values will use the same lambda values, so this means a 14x16 lambda table would absolutely not be needed.

I do think a 2d lambda table might be a good idea. As some engines just cant run right at idle advance when not idling , i.e very slow driving in traffic or other similar situation where non idle advance is actually needed.

[lugnuts]

Autronic uses small idle ignition timing table when TPS is about 2% or less.

Table could be small 4x4 - or just simply 4 settings.
For example, I would run 25 deg at 750 rpm, and 12 deg at 900 rpm, then 6 deg at 1000 to keep idle from racing higher.

[AVP]

yes i agree. Larger lamda is not needed, but for me i need 4 to 6 bins to control idle adequatelly with IAC and ignition timing,and that makes my lamda table even smaller.

Even if i dont use the lamda table at all for values higher than 100kpa since im only using the VE table there, it still is not big enough to accomodate a setting for economy driving. Im not sure about other makes, but audis seem to be able to drive nicely even on 1 lamda on up to 130kpa and 3000rpm,so i would like to take advantage of using that if i can!!

[GintsK]

Anyway I do not understand fully.
Do you want to control idle with mixture: lower than target, then richening?
Regarding this sometimes i have sloppy lambda table : 1.05@ 1300rpm, 0.9@700Rpm and idle target somewhere in the middle.

Another point: IMO it is not possible to not use lambda table. Value from lambda is always included in fuel calculation. Border value if operation point is outside table.

Idle mixture stability from my point of view is more dependent from injector settings (delay and voltage correction).

I see the problem in ignition: idle advance coming from main table. Due to this main table is strongly deformed from desired. I think here is the way to improve economy. Sometimes most effective cruising advance is over 40deg. And it is too close to idle. Especially on high displacement engines mounted in small cars...

I suggest use just one idle advance point (not table) separated from main table, additional with current ign based idle ctrl method. And for improved driveability advance from idle to main table  and back should go smoothly. Not with jump.

Gints

[AVP]

on the contrary i say that lamda/spark should have a small 4x4 or 6x6 dedicated table for idle. Lamda is important as well as spark, but since IAC comes into play, all those vary, as well as VE. But VE already has a large table (16x14) so there is room to be used there. The other tables that are smaller, are leaving only 1 or 2 bins for idle use only.

When i say idle i was thinking like : 800-1000-1100rpm
then: spark for that
then:lamda for those values.

on 1.1.27 i currently have 6 lower left bins on the VE/spark/lamda tables dedicated for idle control

[GintsK]

Does VEMS spark based idle control is not enough?

[AVP]

NOPE!

if vems spark idle was enough, they wouldnt have gone through the bother in fitting IAC settings.
When i use only spark idle, i have idle at 1100rpm, and if i use 10deg of advance to lower it, i get 600C of EGT. Now that is something i dont like.If i use 15deg of advance,then i get sligtly lower EGTs but idle speed goes even higher.

spark idle is rock solid, i do admit,but if you are looking for ideal, then IAC has to work as well and since these guys are going through the trouble of changing everything, this might help in that department as well.

spark based idle is the easy way out of configuring it in my opinion, but even in megatune it says that it is important to use an IAC valve.

[GintsK]

From my point of view IAC control with valve works quite OK (even with "soft" pseudo PWM if set properly), if we talking about speed-density. with additional help with advance I have many street and everyday cars tuned. Yes idle is not so perfect as nowadays cars. But in 90s OE idling was near same as VEMS.

Other thing is Alpha-N with IAC valve. Current slope alike strategy isn't sufficient. Here some small "alpha-N"  table just for IAC valve could be helpful. 3x3. Test car here should be some BMW - M-engine.

I think fine lambda or VE table separated for idle will not solve some important problem: injector characteristics. Often we use bigger injectors than OE. And it works much closer to non-linear area, or on it. If something changes (winter/summer, cold/hot engine) we migrate through this non-linear area and steady VE table - no matter what resolution - not help. Current fuel calculations assume linear charasteristics of injectors.

So some 3D table for injector describing necessary. But 99% of users will not be able to fill such table with well-grounded values. May be some simplifying could help. E.g. autronic describes injectors with some cryptic values.

Gints

[AVP]

yes true, a 3d map would be better. Trial and error once again on this area i suppose

[lugnuts]

Andrey has code written for MT 1.1.5x firmware with simple Injector Dead Time vs Battery Voltage from 7v up to 15v.

With the newest ultra-high quality injectors available from Injector Dynamics, which are flow matched based on dynamically testing and dead time, out hobby cars should start driving as close to OEM quality as possible.

I would suggest that Andrey's dead time code be implemented ASAP into 1.1.6x and if possibly a seeting for 16v would also be added.

Here is some reading about the newest technology aftermarket injectors:
http://www.injectordynamics.com/

[Jamo]

Andrey has code written for MT 1.1.5x firmware with simple Injector Dead Time vs Battery Voltage from 7v up to 15v.

With the newest ultra-high quality injectors available from Injector Dynamics, which are flow matched based on dynamically testing and dead time, out hobby cars should start driving as close to OEM quality as possible.

I would suggest that Andrey's dead time code be implemented ASAP into 1.1.6x and if possibly a seeting for 16v would also be added.

Here is some reading about the newest technology aftermarket injectors:
http://www.injectordynamics.com/

This should be a high priority, the current injector settings are confusing to me, why have an option for open time if the f1 help says set it to 0, what's it's use?

[GintsK]

Voltage and dead time correction is not what I wrote about. These can be achieved with current code if voltage is close to nominal. (not 10V or 16V). 10V and 16V problem can be solved with Andreys code. But anyway most of users will use just approximate graphs...

At small opening times injector characteristic becomes nonlinear. You can see it in graphs in injectordynamics page. On older injectors disturbed area are wider. And this leads to idling issues...
We have no way to describe this area. And this area problem can't be solved just with VE table because same point in VE table not means same injector pulse length every time.

The solution here can be to use new generation injectors (same webpage). E.g. I have case where 2400cc Siemens injectors gives good (for this size) lambda 1.0 idling. True - the only way to achieve operation of these injectors was additional peak-hold board. E85.

I suppose idling related code in OE units has large size.

[lugnuts]

I get what you are saying now.
I don't have experience tuning OEM ecu's, so I don't know about their settings.
But I would imagine that OEM get good quality, tightly batched linear injectors from their suppliers.

Anytime I put an ECU on an engine with OEM injectors, the car runs perfect. Probably 90% of the older aftermarket injectors will behave worse than oem everytime. I demo my PnP ecu on a stock car and people can't even tell that it is not a stock ECU.

Do you have any examples of OEM ecu settings for non-linear injectors?

[GintsK]

Lugnuts, no. I do not saw any 3D injector map. IIRC Motec have something like that. But OE... It is rare to see OE with bigger than 550cc.

Now i catch why often OE idle comes low only when speed drops to zero - this could be the point where ignition map for driving is switched to idle advance. Wht you think?