1.1.81 boost control

[AVP]

i see
i am using an external and i have it plumbed to top and bottom. Stiffer spring only required less DC for the boost to be reached and not spike, but the overall reaction was the same.

[GintsK]

Are  you using an internal wastegate or a external?

If external then plumbing it to the top and bottom would yield the same results as a stiffer spring.

Realy?
What is difference between atmosphere/atmosphere versus boost/boost in both sides of membrane: situation corresponding to solenoid 100%DC

[gunni]

I meant cause he´s upped the spring, he could have put boost on top of the wastegate as well as bottom to force the valve shut for longer and then control boost with the solenoid. This way I have been able to use weak springs make steady strong boost.

[AVP]

in a few weeks time im going to try a 4port solenoid to use in the same configuration as turbosmart eboost. if this doesnt work as well, then im not sure what else i can try, other than going to an electronic boost controller.

by the way, which is the setting that controls rpm on vems? i want to make sure this is not something silly like rpm signal being read wrong and therefore the log is off on the rpms....

[gunni]

A boost controller that handles boost very very well is going to cost close to your vems ecu cost.

it´s about configuration and setup. Something you´d have to do on a electronic boost controller anyway.

Keep at it. The key is in the details.

[AVP]

can someone tell me what do i have to do with the I and D when i need to use higher P values so that to allow for the boost to build up faster?

to me it seems a bit odd, because no matter which PID settings, when looking at the logs the DC is always 100% and then once the boost level is still on 200kpa and target on 300kpa it starts to come down from 100%DC and so i think this is the problem.It should stay on 100% more in order to reach the target value faster.

thanks

[GintsK]

I meant cause he´s upped the spring, he could have put boost on top of the wastegate as well as bottom to force the valve shut for longer and then control boost with the solenoid. This way I have been able to use weak springs make steady strong boost.

Can you clarify how resulting force to W-gate valve stem changes if pressures on both sides of membrane are equal?
In 20VT OE case it atmospheric pressure in both chambers. In old MC variant - boost pressure in both chambers.
Real way is to use two opposite solenoids or 4-port solenoid. Then it is possible to keep upper chamber pressurized, but vent bottom chaber to atmosphere.
Another way might be using very soft spring. And connect just upper chamber. I never seen such setting.

[AVP]

im going to go with a 4 port in a few weeks to see results.

this week ill try making that area a bit richer and ignition timing a bit less to see if it will pick up faster.(more exhaust gasses going through on lower boost levels from 170-150kpa)

[GintsK]

A boost controller that handles boost very very well is going to cost close to your vems ecu cost.

it´s about configuration and setup. Something you´d have to do on a electronic boost controller anyway.

Keep at it. The key is in the details.

Do you mean controller what uses speed of turbine shaft as additional reference??

AVP sent me logs with anytrim applied (seems buggy) where different boost targets (0.6...1.8bar) was kept I would say just close to perfect! Main problem usually is to find right settings for VEMS BC.

[AVP]

which is something i can see not many people other than Gintis and gunni are offering as info at the moment.

some tried settings for audi cars or any cars regarding boost control will be helpfull

[GintsK]

can someone tell me what do i have to do with the I and D when i need to use higher P values so that to allow for the boost to build up faster?

to me it seems a bit odd, because no matter which PID settings, when looking at the logs the DC is always 100% and then once the boost level is still on 200kpa and target on 300kpa it starts to come down from 100%DC and so i think this is the problem.It should stay on 100% more in order to reach the target value faster.

thanks

I saw from your files refDC is just 70%. It is like base position. When boost comes to target, PID adjusts DC to ref DC with ease. Try rise it!
If rising of DC cause problems. I would try to reduce D value. D value works opposite to rapid boost change. Like it is at spoolup area close to target.

[AVP]

you can see from the logs that the refdc is 85 on those range and goes to 77 on higher revs. if i get them higher, the boost spikes at 4000+rpm

so reducing D means that the correction the PID does is sharper and allows for more DC at spool areas?

i have to send you in the afternoon a log with my current setup which seems to work well once boost is in, but its just late

my pid on that is 110/10/28

[GintsK]

AVP you mix RefDC with resulting DC. No?
In RefDC table you have 70% for all boosted rpm range.

[AVP]

that was on one of the runs with anytrim on.
is that what you mean to change? while using anytrim?

[GintsK]

I mean Boost Control->Boost RefDC vs Rpm curve. Set it higher!

With no anytrim as it seems buugy.
 I will try boosttrim on bench one more time with other config and then report.