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Is this erratic boost curve caused by PID settings?
I am trying to flatten out my boost curve to stay on target. Boost is all over the place on the target boost line. Is this caused by improper PID settings in the Holley system?
I am running 60psi C02 pressure commanding 15psi on the dome in the dotted line and 20psi on the solid line.
I’m guessing you’re using the Dome+Map strategy? How well is the dome VS boost table sorted out? The closer is it, the less compensation you’ll need using the PIDs. Right now it’s making large adjustments to the dome pressure in an attempt to keep your target boost on track. Did you set the Dome PIDs using shop air prior to testing? You can get the Dome PIDs extremely close doing this.
I’m guessing you’re using the Dome+Map strategy? How well is the dome VS boost table sorted out? The closer is it, the less compensation you’ll need using the PIDs. Right now it’s making large adjustments to the dome pressure in an attempt to keep your target boost on track. Did you set the Dome PIDs using shop air prior to testing? You can get the Dome PIDs extremely close doing this.
I am using dome control only right now. I did not try to use shop air but I will try that. I am looking up how to do that now. The PID settings are just the base 10/30/0 at the moment. So much reading to do with the Holley system and trying to skim over the parts that don't apply to my situation to find the information I need to know. Every time I look something up it seems I find a new,(different) pdf file I hadn't seen before. It would be GREAT if there was just one manual with a good index.
Shop air testing is easy. Use your shop air to a regulator to the fill solenoid. Set the regulator to whatever pressure you run your CO2 or onboard air to (say 60psi). Now set the strategy to boost VS time and and make the dome pressure table 30psi dome pressure (just for testing sake)Make your transbrake/launch 10 (again, just to test). Now as you toggle your transbrake switch on and off, you should see your target as well as your dome pressure changing. Watch how closely the actual dome pressure follows the target and adjust your PIDs from there. As you mess with the PIDs, you’ll see how they each affect the overall results. I believe mine are 7/22/0, but I don’t have my laptop in front of me to verify.
Shop air testing is easy. Use your shop air to a regulator to the fill solenoid. Set the regulator to whatever pressure you run your CO2 or onboard air to (say 60psi). Now set the strategy to boost VS time and and make the dome pressure table 30psi dome pressure (just for testing sake)Make your transbrake/launch 10 (again, just to test). Now as you toggle your transbrake switch on and off, you should see your target as well as your dome pressure changing. Watch how closely the actual dome pressure follows the target and adjust your PIDs from there. As you mess with the PIDs, you’ll see how they each affect the overall results. I believe mine are 7/22/0, but I don’t have my laptop in front of me to verify.
Awesome. I will do that this week and try it again Saturday at the Valley to see how much more I can get this E.T whittled down!
Put the cursor on the vertical word of what you want to filter (in this case “boost”) and left click. This screen will pop up then hit the “smoothing” drop down and choose a filtering average. The more filter, the straighter the traces become. Tow things, filtering can become an issue if you’re looking for a problem (sometimes the trace is too smooth) and secondly, if you smooth one trace, do them all or they won’t line up chronologically.
I don’t filter and mine damn near lay on top of each other. I run map control though, which you can after your dome is close. With Humphrey solenoids my dome is 14/30/0.5 and map is 0.7/2/0.
09-08-2018, 06:51 PM
Is this erratic boost curve caused by PID settings? 
