wideband o2 control authority
Forum rules
Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
wideband o2 control authority
the higher my control authority gets the worse my engine rpm chases back and forth a few hundred rpm under cruise or any load. even idle. why is this? i moved it down to 3% so it wouldnt do it anymore.
-
Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: wideband o2 control authority
Too much controller authority will do just that - it overcorrects and oscillates back and forth. The closer to correctly tuned the VE table, the less oscillation you get, but you still don't want more than 10% authority or so.
Re: wideband o2 control authority
Basically, your O2 sensor is getting a reading that is way out of whack with the desired target in the particular AFR table entry or entries you are operating in. The ECU tries to adjust the pulsewidth to bring the actual reading closer to the desired target. The amount that the ECU will adjust based on the O2 reading is the percentage selected in the controller authority setting. So, if the actual reading is 20% richer or leaner than the target, but the controller authority is set to 5%, the maximum the pw will be changed will be only enough to result in a 5% correction toward that goal. As you can imagine, a target AFR and an O2 reading that are very different, combined with a high controller authority percentage can result in quick and dramatic changes that are not always desireable. As Matt pointed out, the closer the target AFR is to the corresponding VE table entry (which results in the actual AFR and therefore, the O2 reading) the less rapid variation that takes place. This is great way to tune. By watching the O2 correction percentage at different loads/speeds you will see how close the two key tables are. When there is little correction, and the engine is running well, you are there.
Paul
Paul
Re: wideband o2 control authority
could it also just be a side effect of my big behind cam (236/248 duration) 113lsa 600+lift?