Hey guys im setting up my boost control on the MS3/MS3X. I am using the external EBCS that Diyautotune offers on their website. I read all through the msextra documentation on boost control and i have all the settings to where i believe i want it to be. Im alittle confused on how the maps work for this. I am working on the Boost Control Duty 1 table. I am on stock turbo with stock ports on S5 t2. I want to run 12psi max. Can anyone help me understand how to setup up these tables for what i want? Any help will be appreciated!

 

With open loop boost, you just set the solenoid duty that you want to get close to your desired boost at each throttle position.

 

Is the duty map also in KPA? What numbers I'm entering I guess is my confusion. It's it's in KPA then it makes sense

 

The question doesn't really make sense.

Are you using open loop boost or closed loop boost?

Ken

 

I guess open. But aren't i technically using both? My question is the number i have to enter on the map, are those KPA numbers?

 

It is solenoid duty cycle 0-100% (notice how you can't enter a value above 100)....100% meaning the solenoid is fully open and the wastegate will operate at spring pressure....0% meaning the wastegate will never open and you will blow **** up

Have you read this yet? Boost Control

 

is it better to tune boost in open loop or closed loop?

 

Use whatever you want to use.

I recommend closed loop (especially on MS3 with the initial duty table) since that'll always get you the boost you want no matter what the conditions are as long as you get the PID loop tuned correctly.

Open loop is certainly easier to tune, but then you won't really get the fastest spool and you won't be able to hit the boost you're looking for all the time depending on weather (and other) conditions.

Ken

 

Closed loop is technically "better" as it will try it's best to hold to a boost level that you have set, as well as intelligently controlling the solenoid so that the wastegate only receives boost pressure AFTER the target boost is about to be reached. Instead of simply bleeding off air like the open loop does (allowing boost pressure to reach the wastegate at all times).

Open loop just PWMs the solenoid based on that boost duty table. So you need to find the correct duty cycle that results in the boost you want. However it will vary based on a number of things like air temp and weather. So you'll only be able to get close to the boost you want. Might be higher some days, might be lower.

So, tune open loop first to make sure everything is working and then you can get an idea of how your solenoid responds. Once you know what duty cycles result in roughly what boost level, switch to closed loop and tune it according to the MegaManual.

During this process, make SURE to set your boost cut to the maximum boost you want to see because I'm betting you will create at least one runaway boost situation when tuning closed loop.

 

Awesome thanks for the help guys! I think I understand it alittle better now! Ill post up my MSQs and some screen shots once I get it setup