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      08-15-2020, 08:31 PM   #1
slay2k
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RPM dips under WOT?

Hey boys,

I was reading some of my MHD logs and noticed a couple spots where the RPM actually goes down during full throttle. Here's one:

https://datazap.me/u/slay/stage-2-75...-4-21-26-27-30

With pedal at WOT, we have:

Time,RPM
95.79,2830
95.88,2636

That's dip #1.

95.98,2758
96.07,2751

That's dip #2.

Any idea what's happening here?
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      08-15-2020, 09:32 PM   #2
sbsk518
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Quote:
Originally Posted by slay2k View Post
Hey boys,

I was reading some of my MHD logs and noticed a couple spots where the RPM actually goes down during full throttle. Here's one:

https://datazap.me/u/slay/stage-2-75...-4-21-26-27-30

With pedal at WOT, we have:

Time,RPM
95.79,2830
95.88,2636

That's dip #1.

95.98,2758
96.07,2751

That's dip #2.

Any idea what's happening here?
Did you disable DTC?
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      08-16-2020, 12:16 AM   #3
iqraceworks
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DTC kicking in from loss of traction?? Did you turn it off??
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      08-16-2020, 04:33 AM   #4
Saif2018
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Lot of timing corrections,

Have the coils and plugs been changed recently?
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      08-27-2020, 04:34 AM   #5
slay2k
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Quote:
Originally Posted by Saif2018 View Post
Lot of timing corrections,

Have the coils and plugs been changed recently?
Plugs are new. Coils not so much, but corrections are probably due to shitty gas.

Quote:
Originally Posted by iqraceworks View Post
DTC kicking in from loss of traction?? Did you turn it off??
Wouldn't it show up under torque-limit active in the log?
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      08-27-2020, 05:44 AM   #6
Saif2018
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Quote:
Originally Posted by slay2k View Post
Plugs are new. Coils not so much, but corrections are probably due to shitty gas.



Wouldn't it show up under torque-limit active in the log?
If DTC is on, yes it should show up on Torque Limiter active, if its Zero it means its off, unless I'm mistaken.

Minor rpm fluctuations are not the issue, you need to sort the multiple timing corrections out, would recommend you do the coils (Eldor/Delphi) ones, and use 93 octane at least, which it looks like your already using.
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      08-27-2020, 11:15 AM   #7
iqraceworks
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When the DTC kicks in you will see your throttle closing in the log when your accelerator pedal is still wide open.

If you throttle is staying wide open and your rpms are dropping, then it's got to be pulling timing....from bad gas/low octane.
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      08-27-2020, 12:40 PM   #8
slay2k
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Quote:
Originally Posted by Saif2018 View Post
If DTC is on, yes it should show up on Torque Limiter active, if its Zero it means its off, unless I'm mistaken.

Minor rpm fluctuations are not the issue, you need to sort the multiple timing corrections out, would recommend you do the coils (Eldor/Delphi) ones, and use 93 octane at least, which it looks like your already using.
Sorry, responded late and thought we were talking about injectors. Coils are brand new Eldors. So coils & plugs are both new. So you're saying it's not DTC because it's not showing up in the logs. Correct?

Quote:
Originally Posted by iqraceworks View Post
When the DTC kicks in you will see your throttle closing in the log when your accelerator pedal is still wide open.

If you throttle is staying wide open and your rpms are dropping, then it's got to be pulling timing....from bad gas/low octane.
Well, according to the log, throttle isn't closing when RPM drops. And torque limit is 0, so I assume this wasn't DTC. If it has pulled timing, why would timing correction data be showing 0 on all cylinders during the RPM drops?
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      08-27-2020, 02:11 PM   #9
Saif2018
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Quote:
Originally Posted by slay2k View Post
Sorry, responded late and thought we were talking about injectors. Coils are brand new Eldors. So coils & plugs are both new. So you're saying it's not DTC because it's not showing up in the logs. Correct?



Well, according to the log, throttle isn't closing when RPM drops. And torque limit is 0, so I assume this wasn't DTC. If it has pulled timing, why would timing correction data be showing 0 on all cylinders during the RPM drops?
If plugs and coils are new then its probably your fuel. Try running a less aggressive map to see if it improves the timing corrections if you can't get hold of better fuel.

Torque limiter was showing zero, so I would assume you had DCT fully off?

Last edited by Saif2018; 08-27-2020 at 02:31 PM..
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      08-27-2020, 02:48 PM   #10
slay2k
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On that particular run, I may have left DTC enabled. In either case, it doesn't look like the torque limiter kicked in so I don't think DTC was the problem.

Gas definitely sucks here, I may have to run a 91 map for 93. But if that was the issue, why isn't cylinder timing correction 1-6 showing anything during those times?
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