poongpoong

I've expierienced the same problem. Besides it seams no possible to find good PID Settings which control idle very precise and makes the throttle enough fast with less overshoout at big changes. 
I use a 82mm throttle on  2,2 liter engine, means idle is controlled within 1-1,5%. Even with idle control turned off,  the PiD controller oscillate slowly arround target especially when in gear, because TP seams to jump once integral has summed up enough to overcome friction. Think the push-pull driver must apply current from both sides to control and hold the throttle with more force arround idle. 
I've used Nichols Ziegler methode, measured step response, phase margin etc. to adjust PID's. I also tried Link VDO PID (which oscillate heavy after a step btw!) and spent a lot of time to find sensible PID empirically. Unfortunatelly nothing seams to work well for idle. 
Bad E-thrrottle idle control was discussed a lot over past years. Think it's really time that link engineers investigate into this Problem. 
 

My 2 pence worth , 0.65 on Meths is super rich but the difference between 0.8 and 0.65 lambda is safety the power difference will be very small from what I have found.
We we was running a methanol drag car we was running NTK sensors but was only using the lambda's as a reference we looked upon the EGT's to get an better idea on how the car was running.
Running CLL on full throttle on the Link is something that I would like to do but we dont have the ability to change the closed loop control from low load to high load like Syvecs. I.e have a much smaller adjustment parameter when on high load parameters and it would be good to have the ability to change the CLL % to a different figure from +(add) to -(minus) again like Syvecs.
 
 
 

Cell size was a criterion many years ago to compare ECU's. The VE modell Does a great job. Sometimes you want to move brakepoints arround, but I never felt that there are too less cells in a real world application. You can spent days to tune every cell perfect on the dyno (which needs anyway much more time if you expand the number of cells) and on the track you will find that transient AFR can vary alot depending how boost kicks in. 
I personaly found that I get more stable transient lambda readings (or less lambda error) if I tune TPS vs RPM in the main table and use a 4D overlay with boost compensation (MGP vs RPM). 
That virtually makes your Map even bigger than what Haltech has! And it will make a great job even with 10bar of boost.

Hey,
I think this might have been suggested before. But once you start to understand the wall wetting concept, it starts to explain a lot of other concepts which are described seperately in the current software. 
Example - accel enrichment compensates for changes in wall wetting, but in a fairly crude manner. 

Cold start cranking enrichment is essentially compensating for fuel film build up over the initial cranking period on a cold engine, and the long time period of "tau" on a cold motor.

Fuel cut on decel doesnt really go into this, but if there was awareness of the fuel film depleting during this period then "accel enrichment" would naturally increase again after decel fuel cut. 

It feels like if this was modelled many of the other enrichment features etc could be done away with or minimised. 

Here's a great article on it.

http://www.megamanual.com/ms2/xtau.htm

 

Hi agree that there is some space for improvements on Accel enrich. 
If you enrich enought that you don't see a lean spike at the begining of rappid TP change, AFR's goes usually to low. Even if you set decay rate to 100% and enrich only on one event. 
I can only explain that with fuel film which is built up during extra accel enrichment injection which is then sucked aways on the follow engine cycles, because flow goes up with RPM. 
Some kind of asynchron enrichment may help to built up a fuel film. Or a full fuel film modell. 

I need help on set smooth rev limit for drift car .
 

Hi Adam,
Just to close this off i spent a lot of time trying everything to catch the stall - as i said the gain and anti stall did zip from max to min values.
It really needed a dashpot style fall to idle - which when ethrottle is setup the hold table is removed. 
I managed to create a vitual dashpot using a virtual auxillary triggering a timer and that timer controlling a slowed return to idle using the 3D idle table.
Works very well and might be something others could use if they have a similar problem.
My engine has a very light flywheel and two charger bypasses and 550cc under runner injectors, big cam, remote ethrottle body, head flowed to hell and back etc etc etc all on a 1565cc engine so the combination is probably hard to tune but this made it very well behaved.
Have attached the tune in case anyone else has a similar problem.
Thanks again Adam and please pass on thanks to the engineers, support etc as the g4+ really is excellent.
BR
Renault R8 with v-dashpot.pclr