[spyderturbo007]

Originally Posted by mikelv

Once the ECU reads the adjusted value (because it really cannot tell the difference anyway) it creates a set of maps for timing and fuel.

Actually, that isn't correct. The ECU's maps are defined and do not change. As sensor readings change, the ECU adjust fuel delivery based on those set maps. All you are doing is molesting the airflow reading which in turn forces the ECU onto a different map, or a different section of the same map.

Originally Posted by mikelv

If you are out there doing some tuning and make some adjustments, you are going to wait for the trims to change. Now you get them right and come out the next day; it's colder out, maybe raining, it's going to throw the whole thing off again and have to start the process over.

The ECU does a very good job of compensating for environmental changes all by itself. Although fuel trims may change a little based on changing environmenal changes, I'm never had to re-tune just because it got colder outside.

Originally Posted by mikelv

After it establishes a pattern, it creates a map. That there are multitudes of values that effect this ( like O2 sensor voltage, engine temp, ect…) but that is the basic principle of it.

Once again, the ECU doesn't create maps, they are predefined.

Originally Posted by mikelv

Based on what your profile says, you have a simple, straight- forward setup. Having 550’s and a front-mount, you should be somewhere around (-10%) across the board, O2 voltage around .96V to .98V, and should be able to safely run 18-19 psi of boost with pump gas.

Your math is a little off here. Mathematically, 550cc injectors are 18% larger than stock, so in a perfect world, your SAFC corrections to hit the target AFR should be -18%.

Originally Posted by mikelv

If you are seeing the ECU pull timing a certain points and it’s a pattern throughout the RPM range, you know it’s compensating for detonation. Good luck man, let us know if you need more help.

Not true. Just because timing gets pulled, doesn't necessarily mean you are knocking. IAT's above 86 degrees and the ECU pulls one degree of timing. Coolant temp gets too high, and you lose another degree. Additionally, as you move up in airflow values, the ECU will move you onto a different section of the map. The higher the airflow, the lower the target timing. So, you can get a timing drop just from moving to a higher airflow value. You really need to look at the timing map and corresponding airflow value, coolant temp and IAT to determine target timing.

If you are running larger injectors and have to go positive on the SAFC, there is something wrong. There is no way that injecting 18% more fuel and going 30% positive on the SAFC is normal, nor is it caused by environmental conditions. You need to look at boost leaks, vacuum leaks, shot O2 sensor, etc.