Spark source cylinder pressure limit???

[JLawson240]

So I've got a 12 GT with a JLT series 2 intake on it. The car was tuned previously by Lund, but I've recently started tuning it myself with HP tuners. After dialing in the MAF I decided to add 3 degrees of timing to my Borderline OP and Mapped point 7 tables as that's where the car spends most of its time on the way to redline during WOT. All of a sudden after doing so the car I've noticed the spark source switches to Cylinder pressure limit shortly after going WOT. I'm only commanding about 19-20 degrees which isn't too hot. Can someone help with this? In the attached datalog you can also see at around time 3:49 on the log the commanded AFR goes from a commanded .875 lambda at 5200 rpm down to .79 lambda... in which I'm not commanding anywhere in the tune. My lowest value on my PE table is .845 lambda

[GHuggins]

You should have a cylinder pressure limit table in the tune to raise in the spark section unless it's one of the many Ford files that were never updated by hpt? Hard to tell without the tune file.

[JLawson240]

File attached.... I do have that table... just didn't want to raise it immediately without further input. As far as the extra enrichment I described.. could that be the Cat overtemp kicking in? That was a 5th gear pull after a few runs so heat build up is the only thing I can think of. Couldn't find any other tables for that anywhere

[GHuggins]

Yes, you still have flange, O2 and COT active. Looks like pressure limit's the only thing holding you back right now, but it won't be long and it'll hit some other limiters - that's if you go that high.

[JLawson240]

Thanks man! I bumped up the values in the Cylinder Pressure table, went and did a couple of quick pulls, and that seems to have solved the problem. I've already had to make adjustments to the Torque Truncation table as it was limiting me also and keeping the car from going into PE and Optimum Power cam schedule.

Thank you for taking the time to help! In my short time on the forums I can tell you put in serious work and we all benefit from it.

[GHuggins]

OK, now you're teaching me - what did you change to accomplish that? I've actually got one now that randomly uses a different cam mapping for OP and not sure on. Been a while since I've done any Ford stuff...

[JLawson240]

If you are referring to the Torque Truncation its in the Trans tab>torque management... I maxed out the values for all the gears. Mine had values of around 370-400 ft-lbs in the factory table.

[GHuggins]

Oh, I already have that maxed. Oh well... This is why I know what I know though - always seem to get those oddball unique OS's that make you relearn everything you thought you knew Either way. Thank You for the info.

[JLawson240]

Same to you. Sounds like a fun one.. lol. Just curious if you're seeing anything strange on the spark or torque source while it's happening? If you think about it I'd like to know what the issue ends up being if you figure it out. Thanks!