Discussion and questions related to the course Boost Control
I worked up some boost control tables and wanted someone to see if there are any red flags. The PID talbes were pre set by AEM, but the boost target, wastegate duty cycle, and resolution are the main things i'm trying to verify are correct/safe. I've attached some screenshots of my tables so far. The car has an 18lb wastegate spring installed and I would like to have the car make 36 lbs of boost tapering to 30 by redline (9200rpm); the turbo is a Vband 6466 .82 A/R with a Turbosmart 45mm gate. Any feedback would be greatly appreciated because this is one area that i did not quite grasp when it came time to the worked examples. (Don't mind the boost by gear table, or at least i think that's what that is, i was just playing around with that and will most likely not incorporate it until im more comfortable with the boost target and wastegate duty tables. Thanks again.
I'd suggest starting with the PID tables set to zero so you're effectively open loop. This will then allow you to dial in the base duty table to hit your targets accurately before enabling the pID tables agin for closed loop control. If you genuinely need 100% DC to reach your 36 psi target then you may struggle with closed loop control since you're already maxed out on duty in this area so if your boost is below target there's no way to raise it. Normally I'd recommend a slightly stiffer wastegate spring but this would obviously increase the minimum boost you can use.
Thank you for the feedback. I'll zero out the PID tables and lower the duty cycles to allow for more adjustment. I've also reconsidered the boost target and will keep max boost around 30 psi instead of 36. Trying to keep dyno rental time to a minimum and simplify things, and that 18lb spring should be much better at that boost level.