good day,

I was able to log during a days worth of lapping today and found that my very carefully adjusted fuel was being richened up by the ecu.

I tune for 12. 5 or there abouts with water injection. During the sessions I would loose about half of a point.

I was thinking I was getting some interaction with hot air temps but that doesn't stand to reason. Because no matter how long the session the intake would still be ingesting ambient air. I didn't log coolant temps but it was a relatively cool day and the gauge never indicated anything. I wonder if there is another sensor that is involved that calculates time at high loads, or some such, that I could defeat.

The fuel trims are well within reason.

 

So what are the trims? Injectors? You said a day's worth, ambient temp did not change throughout the day though?

 

If it got warmer, that would explain it.

I've done tuning mid-day when it's warmest, and when I ever do a log at night or early AM, I'm running lean. I've since tried to tune in colder temps

 

Check out the threads on "lean spool" disable? disabling it solved my enrichment problems.

 

I have lean spool disabled. The car has been tuned at warmer temps than exposed to yesterday. The trims are really good, injectors are 650 scaled at 522.

My thinking was that the car had never been tuned under that much stress for so long a period of time. Twenty or more minutes of pretty high abuse.

For the heck of it I've since made the low octane map mirror the high octane map.

 

has anyone had any experience with the ecu switching fuel maps? I always figured the first line of defense would be the timing map. However if no one has seen anything like a load enrichment maybe my car was just dropping down into the lower fuel map.

 

Did the car change back to normal AFR on the drive home?

When you say the intake was seeing ambient temp, what was the ambient temp? What coolant temps where you seeing?

 

That is a good question, I'll do a log soon looking for wot afr. However, the beginning of each session would start out with an afr I would expect to see, or just below.

Well, what I meant, the intake was sucking normal outside air temps as long as the car was at speed.
The day was less than 80 degrees at its hottest, a really nice day. In the morning it was less than 70 for the first two or three sessions. Did not log coolant.

Razor, as I think about it I am beginning to think the car was falling back into the 2nd fuel map. (the car is an 8)

A typical log from the latter part of the day starts out, normal afr as I run down the straight at the start of the session. By the second lap the afr is down to 11.9+- during those same pulls. About six instances of 2 count knock and about the same number of one count. At about nine minutes into the session I start to get 5 and 6 count at the top of fifth gear. At 12 minutes I get 5 count sprinkled around about every twenty to thirty seconds.

 

when its getting richer is your timing the same?

 

timing looks to be following the hi timing map.