Need Help - Tune/Log Review!

[storm]

I am to the point where I need to reach out to someone on the forums for help on what could be causing an issue that I am seeing that my tuner cannot seem to resolve and I would like to confirm there is nothing in the tune that could be causing the issue.

Build Specs: Stock 6.1 hemi long block / SRTMAX cam / 76mm turbo / 80# Ford Racing Injectors / Fore Dual Pump fuel system (1200hp rated) / 2 step colder plugs gapped at 0.028

The good: Car runs flawlessly if I keep boost <10psi. Cold starts great, hot starts great, fuel pressure good at ~50psi and boost ~66 psi. No unusual noises or exhaust leaks. Literally runs perfect. AFR 0.77 lambda at WOT.

The issue: When I turn boost up to 12 psi I CONSISTENTLY get a mis right around 5000 rpms. The AFR will show the same or slightly more rich, 0.73. No knock is registered during this condition and I can confirm knock sensors are working if I build boost too quickly at lower RPMs (3500) i get a blip or 2 of knock. The miss is audible, and there is a noticeable loss in power, but RPMs will slowly continue to climb.

Both a tune and log are attached for reference. As soon as it hits 11+ psi in the log the mis is occurring.

$100 sent to whomever via Paypal if they can identify the problem and issue resolves.

[rays04gtx]

1st Question ,Convertor, stock ?
2nd Question, throttle body, Stock ?
3rd Question, How many miles since the SRTmax cam was installed cam?
I'm asuming by "Stock 6.1 Long block" it's all OEM 6.1 ? pistons,crank, rods.

[fixit]

timing looks good, afr too. injector duty cycle is 86%

plug gap? .03 ish

have you tested with 3 degrees less timing up top?

[f.creek-ranch]

Cant see the probem, but I would take a look at the transmission torque ...

[luciddeath]

I can see the issue.

Your injector tuning is off by a good smudge ...causing it to his 19.1 ms injector pw and most likely throwing a miss. If you need a good remote tune hit me up on facebook. DEMIGOD TUNING.

[storm]

1st Question ,Convertor, stock ?
2nd Question, throttle body, Stock ?
3rd Question, How many miles since the SRTmax cam was installed cam?
I'm asuming by "Stock 6.1 Long block" it's all OEM 6.1 ? pistons,crank, rods.

Converter is stock.
Throttle body is stock.
Srtmax cam has been installed 30k miles.
Yes, stock pistons, crank, rods, heads, even manifolds.

[storm]

timing looks good, afr too. injector duty cycle is 86%

plug gap? .03 ish

have you tested with 3 degrees less timing up top?

Plug gap is .028, I haven't tried pulling timing up top. Would that help to pin point the real problem?

[storm]

I can see the issue.

Your injector tuning is off by a good smudge ...causing it to his 19.1 ms injector pw and most likely throwing a miss. If you need a good remote tune hit me up on facebook. DEMIGOD TUNING.

What is the significance of 19.1 pw? If my IDC is 85% and AFR are good would that matter?

[rays04gtx]

Converter is stock.
Throttle body is stock.
Srtmax cam has been installed 30k miles.
Yes, stock pistons, crank, rods, heads, even manifolds.

Has this issue has been with you since the the Turbo installation ?
or did this issue rear it's ugly head sometime after ?

I see where Lucid is coming from about Injector width, but for Me I think the tune is too lean , but your not complaing about that

looking at the 11.40@119Mph in your sig , your making roughly 670hp which is right about right for the combo.

[storm]

When I ran 11.4 last fall that was on 8-9 psi on 93 octane. Since then I converted to a full fore dual pump fuel system and E85. I recently bumped the boost up and that is when the issue started occurring. I had 2000 trouble free miles at 9 psi on E85 so far this year. My goal for 2022 was to drop into the high 10's and to do that I need to bump the boost up. If I set it at 9 psi it runs strong as hell just hesitates/misses pretty consistently above that.

[storm]

I see where Lucid is coming from about Injector width, but for Me I think the tune is too lean , but your not complaing about that
.

Your comment here really got me thinking. On that entire log 0-105mph log the leanest my AFR got was 0.74 lambda, Once I triggered higher boost it was down to 0.69/0.70 lambda. This seems quite rich. What are you looking at to conclude that the tune is lean? I ask because I am looking to learn, not challenging you. Thanks!

[f.creek-ranch]

When its getting richer there must be a trigger.
injector scaling, fuel pressure, catalytic protection …
I use the 6.4 injectors and 5.7 stock fuel pump with a sc and have set the fuel loss for the pump higher to hold the pressure.
try to figure out why the afr changes to see if the fueling is the reason.

[rays04gtx]

Your comment here really got me thinking. On that entire log 0-105mph log the leanest my AFR got was 0.74 lambda, Once I triggered higher boost it was down to 0.69/0.70 lambda. This seems quite rich. What are you looking at to conclude that the tune is lean? I ask because I am looking to learn, not challenging you. Thanks!

My good sir I didn't think you were challenging me, it's always good to ask Questions.

I was leaning Mechanical, to me it seams like either ring seal ,or exhaust valve closing early and tricks the ECU into thinking it's not providing enough fuel , so it over compensates.........but In Talking to my 4th son(5 boys, 2 girls) this afternoon, after looking at the log and tune with him , he thinks you have a bad injector.

if you slow down your log, @ :03.339 your Lamda drips to .50 and @ :04.376 it hits .31Lamda last super dip is around :.09.550 something has to be causeing that, the 4th Son thinks it's a good tune, he would like to see 1* to 3 more degrees of timing in the WOT...............you're in the good "hemi" Comfort zone in the tune, even if I'd like to see 5% more in the PE table

In the screen shot, you can see the Tune comanding an AFR of .0873 @ 5216 RPM which is 11.45ish(.78 Lamda) but real world its .52 Lamda 7.64 AFR (or .0694 stoch+.0292, and not the tunes .0694+ .0179 = .0873) something has to be causing that spike(or dip how ever you want to look at it.)

[N2speed]

12 PSI on a stock 6.1 is asking for trouble E or not

[PurpleRam]

Your issue stems from ring flutter, that hesitation is the ring end gaps butting up against its self. The oem 6.1 is not designed for boost. The oem ring gaps are less then.012, I don’t remember of the top of my head but they are not suited for high boost

[storm]

My good sir I didn't think you were challenging me, it's always good to ask Questions.

I was leaning Mechanical, to me it seams like either ring seal ,or exhaust valve closing early and tricks the ECU into thinking it's not providing enough fuel , so it over compensates.........but In Talking to my 4th son(5 boys, 2 girls) this afternoon, after looking at the log and tune with him , he thinks you have a bad injector.

if you slow down your log, @ :03.339 your Lamda drips to .50 and @ :04.376 it hits .31Lamda last super dip is around :.09.550 something has to be causeing that, the 4th Son thinks it's a good tune, he would like to see 1* to 3 more degrees of timing in the WOT...............you're in the good "hemi" Comfort zone in the tune, even if I'd like to see 5% more in the PE table

In the screen shot, you can see the Tune comanding an AFR of .0873 @ 5216 RPM which is 11.45ish(.78 Lamda) but real world its .52 Lamda 7.64 AFR (or .0694 stoch+.0292, and not the tunes .0694+ .0179 = .0873) something has to be causing that spike(or dip how ever you want to look at it.)

I really appreciate the feedback. Maybe it is time to upgrade to some better injectors.

[PurpleRam]

Not to be the stick in the mud here or sound like a D!*K , you are at the limit of the 6.1 short block in OEM form, might get another 10-15 HP out of it before you squeeze the top off one of those pistons., right around 680-700 HP with 12-13lbs boost is the limit of the 6.1 , I've gone 730 NA but after tear down there were stress cracks on the edges of the piston tops and that was at 12.3 to 1 compression.

When the SRT boys were thinking these up back in late 03 early 04 , Boost was the last thing on their minds, and current engine thinking was make ring end gaps tight for emissions.....

10s can happen if you put that Cherokee on a diet. at 5k race weight it'll take more HP then those stock pistons can handle.

[storm]

Not to be the stick in the mud here or sound like a D!*K , you are at the limit of the 6.1 short block in OEM form, might get another 10-15 HP out of it before you squeeze the top off one of those pistons., right around 680-700 HP with 12-13lbs boost is the limit of the 6.1 , I've gone 730 NA but after tear down there were stress cracks on the edges of the piston tops and that was at 12.3 to 1 compression.

When the SRT boys were thinking these up back in late 03 early 04 , Boost was the last thing on their minds, and current engine thinking was make ring end gaps tight for emissions.....

10s can happen if you put that Cherokee on a diet. at 5k race weight it'll take more HP then those stock pistons can handle.

You could be right and maybe I did already break a ringland and that could align with what rays04gtx said about ring seal. I do know there are several turbo Jeep guys in stock short block running 9.8-10.1. One is stage6motorsports. Two other guys have run 10.1 on 5000lb race weight pushing 14 psi with a little giggle juice.

[storm]

the 4th Son thinks it's a good tune, he would like to see 1* to 3 more degrees of timing in the WOT...............you're in the good "hemi" Comfort zone in the tune

1* to 3* more timing between 5000 and 6500?

[storm]

In the screen shot, you can see the Tune comanding an AFR of .0873 @ 5216 RPM which is 11.45ish(.78 Lamda) but real world its .52 Lamda 7.64 AFR (or .0694 stoch+.0292, and not the tunes .0694+ .0179 = .0873) something has to be causing that spike(or dip how ever you want to look at it.)

I have about 5 other logs where this symptom repeats. I will take a look at those and see if they are showing the same thing.