High part throttle KR, load <1, boost <1-2psi, AFRs high 14s

Discussion in 'Mazdaspeed 3 Troubleshooting' started by BAT-man, Sep 20, 2020.

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  1. JohnnyTightlips

    JohnnyTightlips Motorhead Silver Member

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    Can we just end this thread. There is no reason to be worried about part throttle KR. All the top tuners for the speed platform say to ignore it. Are they just doing that for the lulz? Just set the tune so it stops telling you about KR under 3k or 1.3 load.
     
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  2. SharksInSpace

    SharksInSpace Planets and shit. Silver Member

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    "No WOT no care." You're exercising futility. Unless your KR at cruise is like constantly pegged at a solid 7+ and never ever drops, stop worrying about it.
     
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  3. The_big_dill

    The_big_dill Greenie Member

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    Interesting progress, thanks for posting this update.

    I don't know how pulling timing will help as its supposedly pulling timing for fuel efficiency, not knock detection.

    Can you compare your ignition timing advance between the 8KR limits and 15KR limits, is it reflected in the actual ignition advance? I am surprised that it will pull this much timing! It would affect drivability quite a bit.

    Whats the ECU part number you have? I am wondering if we can see how many ECU revisions there has been after your current ECU.
     
  4. BAT-man

    BAT-man BANNED Greenie Member

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    So I took a look at my low load/low rpm ignition maps. In my last tunes which were from the old engine, that never had these KR issues, my timing and VVT maps were much higher than the OEM stock values (at least compared to what COBB calls Stage 0, or stock).

    Timing was 10-15 degrees higher in some spots and VVT was a smoothed out version of the COBB stage 3 map. Because the low load/low rpm timing values are very insignificant for any power levers and are really driveability/reliability factors, I decided to make the columns in the 500-1500 rpm range nearly stock, and for loads 0-1.2 for all other rpm ranges also much closer to stock.

    For VVT I also lowered my values from the Stage 3 smoothed out version, although not as drastically.

    Having driven with some of these changes, I do not see the kind of KR during cruise conditions as before, nothing over 5KR, at least. I have now created a map to even more closely approximate the OEM values, and will report on how it goes.

    What's really bugging me is that the previous aggressive values never resulted in the kind of KR in my old two setups and I had two brand new OEM Mazda engines they worked fine on. Wonder if my current engine has some valve seal/carbon issues, but won't know til next year when I do a valve cleaning. For now just want to avoid this LSP type knock while I daily.

    For what it's worth, I disagree with the notion that consistent high KR values around load values of 1 in Gen2's are "no big deal." This thread is for those that share the concern and want to better understand the potential causes and solutions.
    The_big_dill - I don't like removing the ECU from it's relocated spot, as I don't want to mess with the harness, but if I happen to have to do it for some reason during maintenance, I'll let you know. My current theory is that for this engine configuration, my tunes timing and VVT advance targets were way too high and caused knock (possibly LSP related),.
     
  5. The_big_dill

    The_big_dill Greenie Member

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    I missed these comments.

    I wouldn't be bothered by KR if it didn't interfere with my throttle response under load, but it does. I am guessing I am the only one experiencing the slow KR decay and its effect on performance?
     
  6. SharksInSpace

    SharksInSpace Planets and shit. Silver Member

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    Sorry, let me clarify. Like I sort of mentioned, if it's KR that is consistently high, and not the usual jumping around from 1-7 or whatever, or if it's pegging a higher number and then sslloowwllyy decaying, that's something to look into. Agreed with you guys on that.

    But if you're seeing the traditional minor and quickly jumping around KR, between lower values to the occasional higher end 6-7, at cruise throttle and are playing around because of anal retentiveness or something making you feel a need to zero it out, then you're in for a long and painful road.
     
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  7. BAT-man

    BAT-man BANNED Greenie Member

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    Sharks, I'm with you there, and I know gen1/ms6 folks often experience mpg kr, spool-up kr, engine noise kr, and other non-consequential kr types that shouldn't be worrisome. However, i have a theory that a lot of those rarely occur on oem tunes on Gen2s, because most people who mention those are running some OTS or otherwise tuned map and it makes me wonder if it's just an accepted issue that has tune-error roots. I have literally not experienced any of those in 100k miles on the platform. And now this gen2 is doing something that my old one didn't and its the same model year, with nearly the same mods. And as you saw me mention, it was reproducible and went as high as 15 degrees. The car would literally stumble, similar to when you run cruize way too lean. Now after reducing timing per my above post, its down to 3deg, and i think i will be able to get it to 1 or less.
     
    BAT-man, via a mobile device, Oct 9, 2020
    #27
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