Closed loop boost control

[Kkevin]

 Hi, I am having issue of controlling my boost target. It keeps on spiking coming into peak boost. Any input is appreciated.

Thanks

Closeloop boost.pclx spike.llgx

[DerekAE86]

Your boost control solenoid PWM frequency is set at 19hz. This seems very low? What solenoid do you have?

I see you've got two tables configured to run Multi-fuel. But your ratio tables are all different for fuel/ign and boost.

Plus for the Boost Target tables; one is against TPS vs RPM with actual targets in it.
And then one against MAP vs RPM thats all 0 which means it's doing nothing.

As for overshooting - looking at the log it appears you only need around 60-70% duty cycle to maintain your max boost target, but the base has been set around 90% in Table 1 (the currently active one because you're at 10% ethanol).
This means the wastegate initially goes to 90% then closed loop control is pulling it back. And you're hitting MAP limit ignition cut which has been set at 235kPa.

Honestly the PID and stage2/3 settings probably need tweaking too but I wouldnt recommend playing around with it unless you really know what you're doing.

If you're going to fiddle; I'd suggest lowering the cut to a nice safe level, then lowering your boost target much lower than the MAP ignition cut and try to make the cloost loop boost control hit that lower target quickly without overshooting and without hitting the MAP ignition cut limit. 

Once you can achieve this you can raise the target and raise the MAP limit bit by bit until you reach your desired boost levels. 

[Kkevin]

I know what is happening that’s why I’m asking for help. The table is setup that was with 90% at the beginning for spool, car is also setup for flex fuel. And boost cut is set at 235 but thanks for your help anyways

[Adamw]

There is a closed loop boost control setup guide in the help file that goes through each step of setup, I suggest you follow that as your boost control setup is a complete mess.   Turn off the 2 tables, then follow the guide to get a basic starting point set up, get it tuned and controlling well on a single table first before you go adding complication of multiple tables and different fuels.  You should not have 90%DC in your wastgate DC table, set it up per the example in the guide, it should not even be using the wastegate DC table until stage 2 is reached.  You also should not have any values in your target table lower than what the wastegate spring is capable of acheiving - with values of 0-100kpa in the target table you are going to jump straight to stage 3 as soon as the activation conditions are met, completely missing the most important stage 1 & 2. 

[DerekAE86]

What I was getting at was - reduce your base duty cycle so it no longer overshoots then tweak your PID/Stage settings to assit in faster spooling and holding of the target.

This has to be on your car/engine by adjusting and trying different settings and then doing a pull to see how it responds for you.

I recommended lowering the cut and target so while you mess around and learn you don't accidentally grenade your engine.

If you know what's happening then you're already half way to the sollution. The rest is answered if you press F1.