Boost Control / Boost Actuator

I am logging the Boost Actuator Normal Output Duty Cycle and consistently get 15% when active regardless what I change the boost control feed forward values to.

I currently have the following settings:

Boost Actuator Polarity = Inverting

Boost Actuator Minimum = 15%

Boost Actuator Maximum = 85%

Boost Actuator Frequency = 20hz

I know I must be missing something simple. I’ve gone through several MoTec documents, their GPLite boost webinar, The M150 Boost setting and the Boost Control course.

Thanks in advance,

A.A.Ron

Can you upload your package (or email it to me ferg@veracitydata.com), and I will take a look.

Guessing what could be incorrect seems like a waste of time, since there are more parameters than what you have listed.

What are the values of the following channels:

Boost Control Diagnostics, Boost Aim Main, Boost Control Feed Forward Main, Boost Control PID Control, and Throttle Position.

OK, here's the big leap. I looked at the GP-Lite package, and I noticed that there are a few parameters that don't show up on the Tuning->Boost Control worksheet, specifically Boost Control Integral Gain Boost Boundary Minimum, Boost Control Integral Gain Full Boost Minimum, and Boost Control Integral Gain, Throttle Position Minimum. Go to an All Calibrate worksheet, type in "Boost" in the search box and tick "Normal", "Setup", "Diagnostic" and "Tune". Now look through all the parameters, and read the help for each one.

Thanks Dave, I realize referencing the GP Lite video was confusing. I am running a John Reed Racing 2JZ package which is based on the GPR package, so all the boost parameters you are used to and NOT the GP Lite settings.

I’ve read the firmware help for each parameter on the Boost Control page as well as the All Calibrate boost section.

As soon as I get a chance I will add the additional information and package (and possibly a log).

In the meantime here is a link to John's page for a base calibration/package: https://johnreedracing.com/pages/base-calibrations

Boost Control Diagnostics (during boost) = Under Margin

Boost Aim at this point = 24psi

I must not have been logging the Feed Forward as it is blank on my log (I was changing the value for all cells from 15 to 25 in increments of 5) the logs for each of these "runs" had similar boost levels ~16psi and the output duty cycle didn't change all three were 15%

Boost Limit State = Normal

I currently have all of the PID's set to zero as I was trying to tune the Feedforward Table first.

Throttle Position was around 99%

Few other settings:

Boost Active = 60kpa

Boost Margin was around 3psi which is probably too narrow while I am getting this initially set up

Thanks again!

John makes changes to the Boost Control system in his Packages, so there may be something that he has added into that is causing this. Have you spoken to John regarding this issue? As it is a JRR Partner Package, he is SOLELY responsible for providing support for the Package, and not MoTeC.

Hi Stephan - thank you for the response. I haven't reached out to John as I doubt it's an issue with his package versus just me learning to configure everything correctly. Cody Phillips is my dealer (lol... that sounds funny) and has been super helpful. That said, I am on a learning journey, hence my VIP subscription here and trying to absorb all the material on Motec's site/ forum. I try to research/learn things prior to bugging Cody.

Thanks again for the feedback.

I think you will find John to be very helpful. This is a legit support query.

I missed the Under Margin in the Diagnostics before. When the system is in Under Margin, it will drive the gate closed (or how the Duty Cycle has been configured to be the closed position) to try and build the Boost up to the Boost Aim. Once the Boost gets into the window defined by the Boost Margin, the Boost Control system will start to drive the Waste gate Duty Cycle based on the Boost Control Feed Forward table and the PID settings, if they have been configured.

When you are configuring the Feed Forward Table and the Boost Control system, having the Margin to be a larger number is useful as it allows for the Boost Control system to start operating earlier in the boost curve and provides more of a chance for the system to get control and hit the Aim, rather than overshooting.

Thanks again Stephen... I don't think you missed the Under Margin; I edited the post once I got back in front of my PC to add details that David suggested looking at. I figured I needed to open up the margin for now... Andre mentions this in one of his videos.

From the Firmware help I would have thought the Under Margin would apply 100% duty cycle and ignore the Feedforward table.

Boost Margin Help "For example, if Aim is 80kPag and Margin is 20kPag the following behaviour can be observed:

While Pressure is less than 60kPag Control will be 100%.

While Pressure is greater than 100kPag Control will be 0%."

Note it looks like when Polarity = Inverting the Minimum and Maximum get switched around e.g. Boost Actuator Minimum [%] had the following instruction... "When Actuator Polarity is Inverting, (1 - this value) defines the maximum output duty cycle"

Again, I am sure I am missing something simple and will get it sorted out. I'll send a message to Cody Phillips if I can't. Thanks again

100% = Fully Closed Waste Gate, 0% = Fully Open. The help is worded like that to signify that the Boost Control system is requesting a fully closed (Control = 100%) Waste Gate to allow for pressure to build in the system. This why having the Polarity correct is very important. If you have a situation where that request is driving the solenoid in a way that allows for the Gate to blow open, then you will not easily build boost, and the Feed Forward table will be inverted (smaller numbers for more boost). It also means that if you get a boost overshoot and it goes Over Margin, then the M1 will go to 0% Control, and drive the Waste Gate shut, increasing the boost level.

FYI - all resolved. Opening up the boost margin helped initially get things started. For whatever reason the "polarity" had me confused... originally thought it was how the wastegate was plumbed, but second guessed myself and briefly thought it might be tied to the wiring. Anyways, everything is sorted out and on my way to configuring the feedforward table.