Help with LS6 tune on track car

[2 gtos]

I am new to tuning. Car is a 2004 Z06, dedicated road race track car. The drive train is stock from the paper air filter to the stock exhaust. The only modification was the removal of the catalytic converters. the car was professionally tuned. I am getting knock retard at the same point on the track on most laps and continues the entire way down the straight. I notice I am in 4th gear, 100% TPS, and AFR in the high 13s or low 14 using an AEM wideband:
9:51 4kr
11:15 & 12.29 ok
13:39 - 1.8 kr afr 13.9
14:57 & 16:06 OK
17:13 2.7KR sfr 14
18:35 ok but not 100% tps
19:35 2.7 kr 14 afr
I also notice that some of the KR settings have been changed

I am looking for help to make the tune safer. The more specific the advice can be , the better

[RonSSnova]

You need to log Air Fuel Ratio Commanded (Hi Res) PID so you can see what the ecm is telling the AFR to be.
Add this to your config file you are using.

Your power enrichment says it should be approx. 12.7:1.

Looking at your wideband readings in the areas where the car is in closed loop, it shows real lean, yet the short term trims look great. The WB should be reading 14.7 there.
Are you sure the WB is working? It doesn't look like it to me.

For the areas you see KR, you might reduce the timing a couple of degrees. See if it goes away. Or maybe try a colder plug.

[rpturbo]

May need to free air calibrate the WB?

[2 gtos]

It seems the AEM uego should not need to be free air calibrated. I found a procedure in another thread describing how to calibrate the AEM to HPT. I will do this. Thanks for the additional PID suggestion. I will back the timing off a bit and do another log.

[RonSSnova]

Let us know how that goes.
Do you run race gas when at the track?

[2 gtos]

I backed off the timing 1 or 2 degrees in the areas where the knock was occurring. There is now just some random KR here and there, and I can't say I noticed a difference in performance. The AFR reading in HPT is higher than what the gauge is reading at idle and WOT. I used the preprogramed AEM UEGO setting so I guess I need to use a user defined setting. I just need to figure that out now. I was able to have a look at the wideband gauge where I was getting the KR under WOT and it was usually 12.4-12.7 rather than the 13+ it was showing in HPT.

The tune was supposed to be a 93 octane tune. The price for 110 is about double. On a hot day I will usually put a gallon or two of 110 just for extra measure.
Attached is the new data log file with the AFR command high res. I still need to fix the wideband.

[2 gtos]

I adjusted the wideband so that the gauge matched the reading on HPT. It is an AEM wideband but the preset default showed a different reading in the scanner vs the gauge. I data logged again and still seem to have knock retard at certain points (typically when I am WOT coming onto the straight). The car had a vararam and I believe that airflow settings were adjusted as a result. The car now has the stock air intake and I don't believe anything was adjusted back. Engine is stock including OEM intake and exhaust manifolds The only modification is the replacing the CATS with a solid pipe. I have tried 100 octane with no help. Corner worker said that there was black smoke during heave downshift at the end of the straight. This log is from the next session (I decided to log once he told me about this). Open to any suggestions before I seek professional help....

c5Z 7-14-14.hpt8-30-14 session 1.hpl

I am attaching the most recent log and tune

[JimMueller]

Not sure what the process is for AEM, but usually the process is to build the HPT EIO formula to match the accurate wideband reading, not the other way around. I don't have any personal experience with AEM, but I think it's a miscalibrated sensor, bad sensor, bad controller, bad EIO formula, and/or bad fueling calibration. Your VE table is exactly the same as a 'stock' 2004 Z06 from the HP Tuners Repository, and the MAF table is much smoother than I would expect if it had been calibrated using a wideband.

If it were me, I'd visit a local dyno and see what the AFR is on their (presumably) calibrated sensor using the same bung hole your AEM uses, then compare those results with yours in a WOT 4th gear pull. If they are fairly close or mimic the same pattern, then I'd lean towards it being the calibration. If it's not, then determine what steps are most practical for you to make your wideband solution accurate.