[Z06] 02 Z06 Tuning/Mods
Le Mans Master
Joined: Jun 2001
Posts: 7,331
Likes: 518
From: Admit Nothing, Deny Everything, Make Counter Accusations.
Originally Posted by donv
"My confusion is that I thought re-learn would take one back to the original stock programming no matter what has been installed provided that, for example, dyno tuning has not been done. Otherwise, what is the point of re-learn?"
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.
Drifting
Joined: Jun 2005
Posts: 1,824
Likes: 1
From: Middleboro Massachusetts
Originally Posted by rbartick
That is not how it works. During closed loop the PCM always tries to get to Stoich 14.7:1. The method in which Stoich is maintained with a modified motor is different than the method in which Stoich is maintained with a totally stock motor. With a modified motor your PCM will be making fairly large corrections to inaccurate initial fuel metering.
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.
Good point regarding WOT 0.00 on the O2's and LTFT's also.
Le Mans Master
Joined: Jun 2001
Posts: 7,331
Likes: 518
From: Admit Nothing, Deny Everything, Make Counter Accusations.
I should correct my statement. WOT is not a pure guess. WOT is based on input it gets right before it delivers fuel and spark. It just does not know if the delivered mixture was accurate because there is no O2 sensor feedback.
Thread Starter
Racer
Joined: Apr 2005
Posts: 309
Likes: 0
From: Phoenix Arizona
Originally Posted by rbartick
That is not how it works. During closed loop the PCM always tries to get to Stoich 14.7:1. The method in which Stoich is maintained with a modified motor is different than the method in which Stoich is maintained with a totally stock motor. With a modified motor your PCM will be making fairly large corrections to inaccurate initial fuel metering.
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.
Last edited by donv; Oct 12, 2005 at 03:36 PM.
Thread Starter
Racer
Joined: Apr 2005
Posts: 309
Likes: 0
From: Phoenix Arizona
Originally Posted by rbartick
That is not how it works. During closed loop the PCM always tries to get to Stoich 14.7:1. The method in which Stoich is maintained with a modified motor is different than the method in which Stoich is maintained with a totally stock motor. With a modified motor your PCM will be making fairly large corrections to inaccurate initial fuel metering.
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.
Wide open open-loop metering is a different story. WOT metering is a pure guess based on what was seen during closed-loop. The PCM will not know if the guess was correct because there is no O2 sensor feedback at WOT. WOT metering may, or may not, be accurate after you install mods.