1.1.81 boost control

[AVP]

yes, that is because i have a quite high tps vs kpa table. So you see that even with part throttle the boost goes high up. It may be also a bit faster if it was on full throttle!!

i forgot to mention that my timing map with it being much lower from 100kpa and upper, i had noticed that the car was loosing lots of torque on those areas, which is why it is so high. I dont seem to get any ping, but it also feels more torquier( not tested on a dyno yet though).

i will try getting it really low today to see if there is a difference, but assuming that the maps are identical it shouldnt be the reason

[GintsK]

It would be nice to see full range WOT runs on both settings. And, yes, msq too.

If there is difference it might be valuable to sort out cause.

[AVP]

ill try and find old logs of wot to show you

just got back from trying

unfortunatelly nothing i tried today worked.It seems that up to 200kpa there is very slow buildup of boost and then it comes alive.

i did find out however how anytrim works.

anytrim requires the refDC to be zero completelly in order to be taken into account.

so i tried a run with refDC 0 on all rpm and my pid settings to : 240/5/50. without anytrim i had about 230-240kpa full boost.

once i went to anytrim and dialed it in for 160-180----> i got 300kpa

at this point it would be VITAL from someone of the developers and come up and tell us how the BOOST SETTINGS affect each other so that we can stop guessing and start taking proper steps.

how can i have boost with map target only and PID on operation? how is that done? why does it go to 230kpa instead of my 160kpa spring? who decides how it will go?

[AVP]

looked at the logs with more time now and i can only find as a difference that other than the fact that the PID may become a bit more accurate to reduce fluctuations, the only other difference i can find is that at the beggining of the runs, around 3000rpm when the car is slowly going into the 130kpa, the lamda values are fairly low. I have seen anything from 1.12 to 1.03 on those areas.

Now along with low advance, i have been told that more fuel will also help spool up, and on megatune i had 0.96 and then 0.94 on those areas.

Im not sure how much difference that can make, but im hoping it does, as i changed my lamda table a bit to compensate.

as for the anytrim, ill try it since i have it now and hope for the best!

[gunni]

with such high lambda you are not supplying your engine and turbine with energy.

[AVP]

yes i suppose not, so i have reduced that and ill test it tomorrow... fingers crossed...

[mattias]

IMHO, you need to be more scientific about this. With all of these changes, and you are surprised the spool-up is different ?
You will fix this and understand better what works well with your setup, I'm sure.

[AVP]

i may fix this in the end mattias,
but it seems that VEMS developers are not bothering or have forgot to add help to the boost controls, as well as inform all you guys when all features are actually working or not.

i dont like trying to solve an issue with my car and at the same time trying to realise how all these boost settings interact. For example, you can have boost control with PID and rpm/kpa values only. refDC all to zero. Did you know that??

you can add anytrim to the above setup and get boost increase.

Gintis found out that if you have redDC values + anytrim, it doesnt work! did you know that as well?

you can have boost control with no PID and just refDC and rpm/kpa values...

can you have boost control with no PID and no rpm/kpa values, and just use refDC ? and then possibly add PID?

i mean all these SHOULD have been known to users, and not us finding out the hard way. If i knew that i had all these different ways to control boost, then i would plan my action and try them all. It seems though that when changes are implemented and people are unaware of them, even tuners who are involved with the development, it is not easy to give advice thereafter.

just saying to someone: try harder and you'll find it is not something you should put on the F1 help options next to boost...

[GintsK]

AVP point about be more scientific is good! By playing with BC so much, it is surprising how you did not catch refDC purpose and idea. Even with no helpfile. It is the same as for idle!

I just try different refDC settings on the bench. It do not influence boosttarget by single bit. And do not influence buggy anytrim. Anytrim cause disturbed boostarget as previous. Just in same amount with any ref DC.

Please try to be more analytic! Look at your logs. Try to change detail by detail and after each change look to your log. incluiding bosttarget.

[AVP]

on the car, yesterday, anytrim being on 160 and PID 240/5/50 gave minimal oscillations and boost close to my target. refDC was all zero

when i was using any kind of refDC anytrim didnt work, esp. when i was using fluctuating values rather than the same value on all areas.

i will retest tomorrow, but to im trying to explain to everyone that to be scientific, i need to know how all these different aspects work with eachother otherwise im just trying things blindly and going by the final effect.

I dont have a bench tester so i can only test on the road.

try on the bench to go only with PID alone and target kpa, then add anytrim and leave refDC all to zero, and let me know what happens.

[AVP]

Just to clarify a few things in my mind regarding boost control, before being scientific in my options:

boost control options:

1) PID: 0/0/0 + refDC/rpm= zero ---> use only:  map target/rpm

2) PID: 0/0/0+ map target/rpm=zero---> use only refDC/rpm

3) PID--> in use with refDC/rpm= zero AND map target/rpm ONLY

4) PID--> in use with map target/rpm= zero AND refDC/rpm ONLY

5) PID: 0/0/0 + maptarget/rpm + refDC/rpm

6) PID: in use + maptarget/rpm + refDC/rpm

7) PID in use + maptarget/rpm + anytrim  (refDC all zero)

8 ) PID in use + refDC/rpm + anytrim (maptarget all zero)


which one of the above are right and which wrong?

[GintsK]

In short:

Pid 0/0/0 means closed loop control is completly OFF.

In this case works just refDC - you have open loop boost control.
Target table has zero influence on process.
===========

When you start to add small PID values, your BC start to tend to be closed loop. But at small PID values resulting DC will be close to refDC. BC tends to correct initial refDC to target side. Same as for idle. Now BC looks for value from target table. But it not means that target will be reached.

More PID values means less refDC inluence. Due to this you will be able to reach target using refDC table filled way off values.

Try playing with idle - it is the same. Just target comes from two values interpolated inbetween.

[Kenny Watson]

with such high lambda you are not supplying your engine and turbine with energy.

High lambda - lean mixture and high egt, typically improves turbine response, actually. At least in my experience. 

I agree he is changing too many variables at a time. Develop a repeatable test - acceleration in a certain gear, form a certain start rpm to a certain end rpm, at WOT, and work from there.

[AVP]

well, just came back from more runs.

still with more fueling, it did not make much difference. I still have the rpm difference of about 150-200rpm esp. on 3d gear.

on all occasions, as gintis mentions open or closed loop control, it seems that the boost is only reaching the target on the way it wants. no sooner.

when PID is completelly off, if i am too aggressive with the refDC, then boost can be ok for 3d gear(as i use higher refDC from 2500-3900) but then on 5th and 6th gear, it will spike and overshoot as there is much higher load.

therefore closed loop MUST be used to avoid this.

now, either i use closed or partially closed loop, OR anytrim for that matter, i end up with the same figure, 100%DC as it should and then a drop off as i come close to the target values. However, even though i get similar values as i did on megatune as far as when the DC drops(around 3700rpm on 3d gear) i end up with much slower boost rise, even now that the fueling is much improved. SO i cannot explain it,other than to say that there might be wrong with the turbo itself? (turbo is only 6month old, and has never been abused).

All my tests are done methodically. I dont go changing 3 or 4 settings at the same time. All runs are done on 3d and 4th gear on the areas which are involved in the problem 2800-4500rpm.

Personally, i give up. I dont know what the problem is. I have read about PID configurations, i have managed to tune my idle fine, this has been a nightmare to tell you the truth.

[GintsK]

All my tests are done methodically. I dont go changing 3 or 4 settings at the same time. All runs are done on 3d and 4th gear on the areas which are involved in the problem 2800-4500rpm.

May be you do your tests methodically. But you do not give much chance to help you. Both logs was not from similar circumstances: one was not WOT, other was WOT just from 3000rpm.