Does ECU Listen to Knock above 5000rpm?
So what happen to piggy back EMS like Ultimate, SS, Unichip that rely on the ECU to pull timing when detonating? That is scary then .... So how do you judge if you are getting false knock on the higher rpm with utec?
I can't speak for the other ems' out there; but for UTEC, I left the knock thresholds defaulted the way they were set from TXS, since their settings pretty conservative.
False Knock vs. Real Knock:
To preface - In Open Loop, UTEC does not rely on the ECU to detect or react to knock.
I don't consider an isolated (1) count knock to be real knock with UTEC. Isolated (1) counts can be mechanical noise, misinterpretation by UTEC, knock mic not calibrated finely enough, or a host of other things. If I get a (2) knock count or higher, or if I get a string of (1) counts, I consider those situations to be real knock, and adjust the tune accordingly. If the knock goes away in those trouble spots (which it always does in my case), that lets me know I had real knock. But a few random (1) counts here or there is not a big deal.
Last edited by gothchick; Oct 23, 2008 at 11:19 AM.
This is all I could find in the EC section of the FSM. Kinda vague...
Component Description NBS0007X
The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the ECM.
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not operate under normal driving conditions.
If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Component Description NBS0007X
The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the ECM.
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not operate under normal driving conditions.
If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
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The reason I'm asking is when I'm at the track (Drag) I knock like crazy but dont knock on the street. I do lots highway WOT race and tuning and never knock like this, every now and then I'll play with my Gtech and do some 1/4 pull and never knock.... I think I'll have have a more conservative tune for the track.. Anyways thanks for the info...
I bet you're knocking at the drag strip cause you're heat soaking while you're staging.
Meth/water injection, bigger rad, oil cooler, heat wrapping, venting, maybe a manual switch for your fans, etc would probably really help. Heck some guys will even put a bag of ice on top of their plenum when they're staging. lol~ :-)
Meth/water injection, bigger rad, oil cooler, heat wrapping, venting, maybe a manual switch for your fans, etc would probably really help. Heck some guys will even put a bag of ice on top of their plenum when they're staging. lol~ :-)
Last edited by gothchick; Oct 23, 2008 at 11:39 AM.
I bet you're knocking at the drag strip cause you're heat soaking while you're staging.
Meth/water injection, bigger rad, oil cooler, heat wrapping, venting, maybe a manual switch for your fans, etc would probably really help. Heck some guys will even put a bag of ice on top of their plenum when they're staging. lol~ :-)
Meth/water injection, bigger rad, oil cooler, heat wrapping, venting, maybe a manual switch for your fans, etc would probably really help. Heck some guys will even put a bag of ice on top of their plenum when they're staging. lol~ :-)
Hmmm... Another thought I had; Is your Open to Closed Loop Delay set to "0"? If it's set to 1 or 2, that can cause shift flare, which could cause your Meth, shift, delay to get out of synch...
Mine is set to 0... I didn't really get to look at my logs closely at the track but now I think I found the culprit.. This past few weeks I had increased my meth from 40% to 50% meth and did my tune accordingly. I rarely (almost never) hit load 10-50 at above 6000rpm so I forgot to add more fuel above that.. I was speed shifting at the track and did a few power shifting and I noticed that most of the worst knock was when I powershifted... looking at the logs I'll be hitting load 10-50 at around 6000-7000rpm so my A/F was around 12.9-13.5 when knocking... It was stupid of me to left the higher rpm untouched coz I never hit them anyways... So right now I added more fuel at the higher RPM and lower loads so when I hit them next time I powershift I'll have ample of fuel.. I hit those load very quickly though coz I'll hit load 30 and it will jump straight to 60..
Here's one sample of my log..
You'll see I never really lifted my throttle all the way and when I shifted I hit load 20 then stratight to 60 were my A/F is lean..
Here's one sample of my log..
You'll see I never really lifted my throttle all the way and when I shifted I hit load 20 then stratight to 60 were my A/F is lean..
Code:
[TSMP][RPM][PSIG][MAF][TPS][LOD][KN][SIG][IDC%][IGN][VOEF][BMV][MMV][WBO2][AIT][CLT][IGNT] 000.80 5101 +3.6 4.8 98 50 0 20.8 74.4 17.1 +5.0 000 4.6 12.19 016 086 001.00 5609 +6.0 5.0 96 70 0 22.8 89.0 17.9 +5.0 000 4.6 11.95 017 087 001.20 6100 +7.2 5.0 96 70 0 23.9 94.8 17.5 +5.0 000 4.6 11.83 018 087 001.40 6844 -2.8 3.8 0 0 0 25.8 65.6 ECU 100 000 2.2 11.89 019 088 001.59 6127 -11.4 2.0 1 0 0 33.8 6.5 ECU 100 000 4.1 12.49 018 087 001.80 6145 +0.8 4.5 100 20 0 16.0 54.9 19.2 +5.0 000 4.4 13.40 016 086 001.99 5575 +3.6 4.7 100 50 0 21.2 59.7 15.6 +5.0 000 4.4 13.18 018 087 002.20 5233 +5.8 4.7 100 70 0 03.1 74.7 15.1 +5.0 000 4.6 12.16 019 087 002.40 5189 +7.2 4.9 100 80 0 09.0 84.8 15.0 +5.0 000 4.6 11.64 018 087 002.59 5319 +7.5 5.0 100 80 0 14.0 89.9 15.4 +5.0 000 4.6 11.63 020 087 002.80 5528 +7.1 5.0 100 70 0 20.8 88.6 15.7 +3.0 000 4.6 11.66 020 087 003.00 5784 +6.9 5.0 100 70 0 22.9 89.3 17.0 +3.0 000 4.6 11.66 020 087 003.20 6038 +6.8 5.0 100 70 0 22.9 90.7 17.2 +3.0 000 4.6 11.67 021 088 003.40 6266 +6.8 5.0 100 70 0 23.7 91.6 17.0 +3.0 000 4.6 11.67 021 087 003.60 6513 +6.9 5.0 100 70 0 23.6 94.2 18.0 +3.0 000 4.6 11.66 022 088 003.80 7423 -7.2 2.9 55 0 1 42.8 72.0 ECU 100 000 2.2 12.29 023 088 004.00 7025 -4.0 4.0 100 20 3 34.0 51.1 24.1 +3.0 000 4.4 13.37 021 087 004.20 5959 +4.8 4.7 100 60 14 22.0 61.7 06.0 +3.0 000 4.5 12.96 022 088 004.40 5252 +7.0 4.9 100 80 0 20.7 79.1 13.8 +3.0 000 4.6 12.12 021 087 009.29 5180 +8.4 4.9 100 80 0 21.9 85.8 12.3 +3.0 000 4.6 11.44 024 088 009.33 5206 +8.1 5.0 100 80 0 21.1 87.5 13.4 +3.0 000 4.6 11.38 023 088 009.37 5258 +7.7 5.0 100 80 0 21.0 87.9 14.8 +3.0 000 4.6 11.39 024 088 009.40 5400 +7.1 5.0 100 70 0 21.8 87.5 15.2 +3.0 000 4.6 11.43 025 088 009.44 5528 +7.2 5.0 100 70 0 21.7 87.9 15.4 +3.0 000 4.6 11.51 025 088 009.47 5666 +7.3 5.0 100 70 0 22.9 89.1 15.1 +3.0 000 4.6 11.46 026 088 009.50 5799 +7.3 5.0 100 70 0 22.9 89.9 15.5 +3.0 000 4.6 11.40 026 088 009.52 5921 +7.3 5.0 100 70 0 23.8 90.2 15.9 +3.0 000 4.6 11.39 026 088 009.55 6052 +7.3 5.0 100 70 0 23.9 91.3 16.2 +3.0 000 4.6 11.38 026 088 009.58 6181 +7.3 5.0 100 70 0 23.9 92.4 16.0 +3.0 000 4.6 11.38 026 088 009.61 6263 +7.1 5.0 100 70 0 24.8 93.8 16.0 +3.0 000 4
Last edited by athenG; Oct 24, 2008 at 09:48 AM.
Yikes. I see what you mean about that (14) count knock... That's pretty severe.
Cliff Notes:
TPS dips to 55%,
Load drops to 0%,
ECU takes over briefly,
AFR spikes up past 13,
Timing hits 24,
TPS goes back up to 100%,
You're already back in boost,
BAM - knock!
Strange. The UTEC transioned back to ECU Closed Loop. You were at 55% TPS @ 7000rpms... I wouldn't think it would transition back to Closed Loop or 0% Load in that split second... What is your TPS threshold set too?
Edit: Also - What gear was the shift knock in? I ask because I notice you had almost the same condition at the top of the log and no shift knock...
Edit to the Edit: I see the difference. You didn't have a timing spike at the top of the log, so maybe when it spiked towards the bottom of the log, that was enough to induce knock.
Another difference I see is that you're hitting boost sooner with the AFR/ Timing spike at the bottom of the log, because you didn't lift the throttle as much (only goes down to 55%).
On the bright side, UTEC was pretty good at detecting and reacting to the knock event. Pulled timing WAY back (from 24 to 6) in a split second~ :-)
Hopefully richening up those areas will eliminate the knock. I bet it will... Not much you can do about the timing spike since that was caused by the ECU.
Cliff Notes:
TPS dips to 55%,
Load drops to 0%,
ECU takes over briefly,
AFR spikes up past 13,
Timing hits 24,
TPS goes back up to 100%,
You're already back in boost,
BAM - knock!
Strange. The UTEC transioned back to ECU Closed Loop. You were at 55% TPS @ 7000rpms... I wouldn't think it would transition back to Closed Loop or 0% Load in that split second... What is your TPS threshold set too?
Edit: Also - What gear was the shift knock in? I ask because I notice you had almost the same condition at the top of the log and no shift knock...
Edit to the Edit: I see the difference. You didn't have a timing spike at the top of the log, so maybe when it spiked towards the bottom of the log, that was enough to induce knock.
Another difference I see is that you're hitting boost sooner with the AFR/ Timing spike at the bottom of the log, because you didn't lift the throttle as much (only goes down to 55%).
On the bright side, UTEC was pretty good at detecting and reacting to the knock event. Pulled timing WAY back (from 24 to 6) in a split second~ :-)
Hopefully richening up those areas will eliminate the knock. I bet it will... Not much you can do about the timing spike since that was caused by the ECU.
Last edited by gothchick; Oct 24, 2008 at 01:10 PM.
The bottom log is when I powershifted from 2nd to 3rd gear.. I dont hit full boost on 2nd gear and that is why you see the boost build slower compare to 3rd gear were I usually hit full boost. I think the timing spike is a delay from Utec coz my timing map at load 20 and 7000rpm is about 17-18 deg. Anyways I may go back to Etown in 2 weeks so I'll see if it improves..
Edit: my Open Loop transition is 20 I think...
Edit: my Open Loop transition is 20 I think...
Last edited by athenG; Oct 24, 2008 at 01:04 PM.
Hey, I PM'ed you about Utec and NA tuning...
AthenG what size injectors are you using? I was checking out your log and with 600's I only hit the 50% column at 7.8 to 8.1 psi. Mid 8 psi I hit the 60% column. Hell last week I had a boost spike when it was about 45 degrees out, was logging at the time got 38 knock counts at 5200 rpms boost spiked to 12 psi and hit the 80% column. I think this utec has saved my motor twice now. In your other post you mentioned about the UPREV picking up knock I would like to know that as well.
I'm using only 440cc inj (Deatschwerks) so it is more 400cc
You can see my IDC is around in the 90's% above 6000rpm. Check your "Map Min/Max value for Mapping" coz that will dictate what load you'll hit on certain boost. I have a feeling that you are set from 1-16psi and that is why you only hit 50% on 7-8psi. If you are only boosting 8 psi then I would set it from 1-10 psi, this way you still have 2 psi left in your load column just in case you overboost and set your overboost cutoff to 10psi. You are wasting precious resolution by spreading your load that far. I'm not that familiar with Orisis yet but if it just rely on the ECU to pull timing when knock is detected then it can be trouble since ECU dont monitor or wont react to knock past 5000rpm...
You can see my IDC is around in the 90's% above 6000rpm. Check your "Map Min/Max value for Mapping" coz that will dictate what load you'll hit on certain boost. I have a feeling that you are set from 1-16psi and that is why you only hit 50% on 7-8psi. If you are only boosting 8 psi then I would set it from 1-10 psi, this way you still have 2 psi left in your load column just in case you overboost and set your overboost cutoff to 10psi. You are wasting precious resolution by spreading your load that far. I'm not that familiar with Orisis yet but if it just rely on the ECU to pull timing when knock is detected then it can be trouble since ECU dont monitor or wont react to knock past 5000rpm...
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