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      05-12-2021, 01:52 PM   #1
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okay need some eyes on my logs please

what in the hell is happening here..

back to back logs.. second one obviously the car breaks up and it's caused by a fuel pressure drop..
hpfp is dorch stage 2 and this problem exists with full e85 on a custom tune with both a stock lpfp and with a stage 2.5 lpfp. these runs are both with the aftermarket lpfp. nobody seems to have any idea.

this was fuel pressure what clean...
https://www.bootmod3.net/log?id=609c...0b434b387174ff

this one, fuel pressure goes nuts...
https://www.bootmod3.net/log?id=609c...729b2547ade408
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      05-12-2021, 02:05 PM   #2
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Quote:
Originally Posted by Phantom10R View Post
what in the hell is happening here..

back to back logs.. second one obviously the car breaks up and it's caused by a fuel pressure drop..
hpfp is dorch stage 2 and this problem exists with full e85 on a custom tune with both a stock lpfp and with a stage 2.5 lpfp. these runs are both with the aftermarket lpfp. nobody seems to have any idea.

this was fuel pressure what clean...
https://www.bootmod3.net/log?id=609c...0b434b387174ff

this one, fuel pressure goes nuts...
https://www.bootmod3.net/log?id=609c...729b2547ade408
I wouldn't necessarily say the fuel pressure drop cause the break up. First, it looks like you hit soft limiter at the top of 2nd. When you shifted to 3rd your timing was already bad and then you had a boost spike, then knocked at 5555 rpm and your timing went to shit and never recovered for the rest of the run. I suspect the "breaking up" was the timing corrections.

Your fuel trims are also consistently positive to either the map needs more fuel added or you are misfiring enough that there is unburned O2 in the exhaust making it read leaner than it actually is. They are almost the same in the clean run too though so i would say maybe the former.
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      05-12-2021, 02:20 PM   #3
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Quote:
Originally Posted by thejeremyman9 View Post
Quote:
Originally Posted by Phantom10R View Post
what in the hell is happening here..

back to back logs.. second one obviously the car breaks up and it's caused by a fuel pressure drop..
hpfp is dorch stage 2 and this problem exists with full e85 on a custom tune with both a stock lpfp and with a stage 2.5 lpfp. these runs are both with the aftermarket lpfp. nobody seems to have any idea.

this was fuel pressure what clean...
https://www.bootmod3.net/log?id=609c...0b434b387174ff

this one, fuel pressure goes nuts...
https://www.bootmod3.net/log?id=609c...729b2547ade408
I wouldn't necessarily say the fuel pressure drop cause the break up. First, it looks like you hit soft limiter at the top of 2nd. When you shifted to 3rd your timing was already bad and then you had a boost spike, then knocked at 5555 rpm and your timing went to shit and never recovered for the rest of the run. I suspect the "breaking up" was the timing corrections.

Your fuel trims are also consistently positive to either the map needs more fuel added or you are misfiring enough that there is unburned O2 in the exhaust making it read leaner than it actually is. They are almost the same in the clean run too though so i would say maybe the former.
hmm okay.. it may need a lower afr target. I'll see what Cary says.
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      05-12-2021, 03:18 PM   #4
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lower afr target won't help the stft. positive stft is the result of the car not getting to the target AFR with the fuel/injector scaling, so it has to step in and correct it so you reach your AFR target.

i see a spike of overboost at 5431 rpm, which throttle closes to correct, and it coincides with your rpm rise getting rough. at this time, the hpfp does take a dip too, but i don't understand why. i am also investigating a problem i have with misfires after quick gear shifts (6mt). in my case, hpfp also takes a dip and car 'breaks up'
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      05-12-2021, 03:31 PM   #5
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Quote:
Originally Posted by designatedposter View Post
lower afr target won't help the stft. positive stft is the result of the car not getting to the target AFR with the fuel/injector scaling, so it has to step in and correct it so you reach your AFR target.

i see a spike of overboost at 5431 rpm, which throttle closes to correct, and it coincides with your rpm rise getting rough. at this time, the hpfp does take a dip too, but i don't understand why. i am also investigating a problem i have with misfires after quick gear shifts (6mt). in my case, hpfp also takes a dip and car 'breaks up'
Yeah its not about target AFR its about the actual fuel tables in the tune. Lowering the target AFR while keeping the same fuel tables will only make STFTs higher (more positive) to try and reach the target. The target AFR may be fine the tune just needs more fuel to get there.

The HPFP dips immediately after the shift even before the boost spike. I don't have a obvious explanation either since its fine in the other log and on other shifts. The only difference is that this is a 2-3 shift, so im wondering if it happens only on the lower gear shifts when there is a bigger RPM drop between gears. The RPM rise gets rough because of the throttle and boost modulation and all the timing being pulled.
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      05-14-2021, 02:39 PM   #6
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Quote:
Originally Posted by thejeremyman9 View Post
Quote:
Originally Posted by designatedposter View Post
lower afr target won't help the stft. positive stft is the result of the car not getting to the target AFR with the fuel/injector scaling, so it has to step in and correct it so you reach your AFR target.

i see a spike of overboost at 5431 rpm, which throttle closes to correct, and it coincides with your rpm rise getting rough. at this time, the hpfp does take a dip too, but i don't understand why. i am also investigating a problem i have with misfires after quick gear shifts (6mt). in my case, hpfp also takes a dip and car 'breaks up'
Yeah its not about target AFR its about the actual fuel tables in the tune. Lowering the target AFR while keeping the same fuel tables will only make STFTs higher (more positive) to try and reach the target. The target AFR may be fine the tune just needs more fuel to get there.

The HPFP dips immediately after the shift even before the boost spike. I don't have a obvious explanation either since its fine in the other log and on other shifts. The only difference is that this is a 2-3 shift, so im wondering if it happens only on the lower gear shifts when there is a bigger RPM drop between gears. The RPM rise gets rough because of the throttle and boost modulation and all the timing being pulled.
changes made.. but check out fuel pressure going into 5th

https://www.bootmod3.net/log?id=609e...729b0442ad9494
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      05-14-2021, 02:48 PM   #7
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Quote:
Originally Posted by Phantom10R View Post
changes made.. but check out fuel pressure going into 5th

https://www.bootmod3.net/log?id=609e...729b0442ad9494
You're making (holding) more boost in 5th than the other gears. Not much more, but only thing i see that could affect HPFP. Maybe try a 5th gear pull log?

You're actually a decent amount below target in 3rd and 4th and i thought i saw stage 2+ OTS BM3 maps holding closer to 20psi than you are in with stock turbo. Could be because you are doing 3-4-5 rather than 4th gear pull though and you are revving out 6500+.
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      05-14-2021, 02:50 PM   #8
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Quote:
Originally Posted by Phantom10R View Post
changes made.. but check out fuel pressure going into 5th

https://www.bootmod3.net/log?id=609e...729b0442ad9494
could you try a WOT single 5th gear pull and see if the hpfp drops to determine if gear change is the issue.

what turbo are you on? you're pretty off target boost
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      05-14-2021, 02:52 PM   #9
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if anyone in here is 6mt, i'd love to see your multi gear logs!

we've all been conditioned to do single gear pulls, and have been blind to gear change issues! i want to rule out my hardware, so if multiple people are misfiring at gear change, i think its a tuning issue.
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      05-14-2021, 02:57 PM   #10
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Quote:
Originally Posted by designatedposter View Post
could you try a WOT single 5th gear pull and see if the hpfp drops to determine if gear change is the issue.

what turbo are you on? you're pretty off target boost
I guess we think alike haha, see my post above yours.
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      05-14-2021, 02:58 PM   #11
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Quote:
Originally Posted by designatedposter View Post
if anyone in here is 6mt, i'd love to see your multi gear logs!

we've all been conditioned to do single gear pulls, and have been blind to gear change issues! i want to rule out my hardware, so if multiple people are misfiring at gear change, i think its a tuning issue.
I typically recommend a 1-2-3-4 (for auto people) from a dig to go along with a couple 4th gear pulls if you are trying to do a complete assessment. 1-2-3-4 captures a lot more of the transient behavior and how the car responses to fast changes in RPM, low load, gear changes, etc.
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      05-14-2021, 05:44 PM   #12
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Quote:
Originally Posted by designatedposter View Post
Quote:
Originally Posted by Phantom10R View Post
changes made.. but check out fuel pressure going into 5th

https://www.bootmod3.net/log?id=609e...729b0442ad9494
could you try a WOT single 5th gear pull and see if the hpfp drops to determine if gear change is the issue.

what turbo are you on? you're pretty off target boost
stock turbo..

not sure I can just do a single 5th gear log really.. very difficult to find the room and no traffic.
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      05-14-2021, 05:46 PM   #13
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Quote:
Originally Posted by thejeremyman9 View Post
Quote:
Originally Posted by Phantom10R View Post
changes made.. but check out fuel pressure going into 5th

https://www.bootmod3.net/log?id=609e...729b0442ad9494
You're making (holding) more boost in 5th than the other gears. Not much more, but only thing i see that could affect HPFP. Maybe try a 5th gear pull log?

You're actually a decent amount below target in 3rd and 4th and i thought i saw stage 2+ OTS BM3 maps holding closer to 20psi than you are in with stock turbo. Could be because you are doing 3-4-5 rather than 4th gear pull though and you are revving out 6500+.
yeah I gotta take I can get based on location.. ill try but indunno
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