Help: Problems with GT500 still

I posted below on the issues I am having tuning a customer's 2010 GT500, with VMP 2.3 supercharger. We had it on the dyno again today, and I have more data to report on the problem. We made three WOT pulls on the dyno. None was as good as the clean WOT runs we'd seen with this car before, and each successive run was worse. Looking at the logs (attached), what stands out is that the timing gets dramatically lower with each successive run. By the third run, we're down to 6 degrees max!

The engine had at least 5 min to cool between each run, and the IAT and ECT are very close between them. Looking at the timing logs, the timing plots look quite smooth, just very low. The timing plunges to a low level as soon as the throttle is floored, and stays down the whole way up. It's as though the ECU is "learning" from run to run, and pulling more timing each time, kind of like a GM low-octane/high-octane learning.

I think the power issues are pretty much strictly timing related. The MAF voltage vs. RPM is very similar through all 3 pulls, which would tend to eliminate belt slippage or ETC issues.

I've attached a JPEG of three dyno pulls: a clean high power run, and the last two low power pulls from today. I've also attached the current tune file, a log from a clean pull, the 3 logs from today's sessions, and the config file.

If somebody could make some suggestions, I'd be grateful. The time and frustration are mounting up!

Edit: One oddity I noted is that the Barometric pressure varies as much as 9 KPA between (and within) the pulls?

Couple of things....

Our IAT Spark Correction and ECT Spark Correction tables were not correctly mapped. I have fixed that, so redownload 2.24 and it will be correct.

In the below screenshot is the stock values (what was in your file).

These two tables get multiplied together to come up with a spark value to remove for hot inlet air temps., so you can easily see if the air temperature gets warm these cars pull timing out very quickly.
http://brooksspeed.com/hptuners/forumimages/IAT.JPG

I'm not allowed to advise you on what values to use, but you can setup the spark retard to not pull out so much when the temperature is reasonable and it will help this.

Currently our logger is only recording the SAE Intake Air Temp PID which is the one in the inlet, but the PCM is using the second air temp sensor in the intake. Our scanner will be getting a major update soon which will allow you to read the proper sensor along with a host of other parameters you currently can't log.

Thanks much Eric, I was already thinking along these lines (and wondering about those funky axis values in the temp correction tables :) I suspected the intercooler temps were increasing run by run, taking out more spark each time, and I didn't notice that because we can't yet log what the SCT tuner types call IAT2. Glad to hear the logger will be updated soon, it seems like otherwise HPT is becoming a robust Ford solution, from reading this forum anyway.

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Originally Posted by MCScott

Thanks much Eric, I was already thinking along these lines (and wondering about those funky axis values in the temp correction tables :) I suspected the intercooler temps were increasing run by run, taking out more spark each time, and I didn't notice that because we can't yet log what the SCT tuner types call IAT2. Glad to hear the logger will be updated soon, it seems like otherwise HPT is becoming a robust Ford solution, from reading this forum anyway.

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Once I get 2011-2014 Mustang released I am going to revisit the older definitions to make sure we don't have these types of errors in them. We are hoping to be a major player very soon.