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really bad knock all of a sudden

Old Feb 5, 2010 | 12:01 AM
  #121  
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From: Hayward
Originally Posted by Clipse3GT
For example. If you use large injectors (i.e. 1000cc) if for some reason you are using lower scaling in order to be close to 0 with your LTFT's. IF you do a WOT pull and your HIGH OCT map is set above 12.88 during spool up. The ECU WILL DEFAULT the map to 12.88. Even if your map is set to 14 during spool up.

This is the example from a FP RED c 1000cc. Notice the spool up AFR MAP.


The ECU will not go above 12.88, it is capped.
Hmm that is interesting I've never seen it capped so rich with 1000cc's before.

I also never look at AFRMAP as it means nothing to me, only final real AFR.

I've never had a fuel map looking like what you posted for spool. Can you send me your ROM for that log? I'd be really interested to see it.

- Bryan
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Old Feb 5, 2010 | 12:02 AM
  #122  
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From: Hayward
Originally Posted by tephra
well I just did a couple of pulls on the way home to see if anything has changed.

this is the same configuration (3" DP + HFC) and same tune (original tune + 1pt in the fuelmap)

and it KNOCKED to absolute F&*^

looking at the log now...
Tephra,

Send me an email. I would like to help you out..... if I can.

- Bryan
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Old Feb 5, 2010 | 12:04 AM
  #123  
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thanks bryan - i just updated that last post...

I can send you the whole log if you like :|
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Old Feb 5, 2010 | 12:06 AM
  #124  
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So the log doesn't look terribly lean.

I just understand how 10+ pulls can be good, then BANG all of a sudden 30 knocksum

seem to me like a failing fuel system, either relay or pump...
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Old Feb 5, 2010 | 12:11 AM
  #125  
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From: Hayward
Originally Posted by tephra
thanks bryan - i just updated that last post...

I can send you the whole log if you like :|
Send me an email with your rom and latest logs. I take it you are logging AFR with them correct?

- Bryan
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Old Feb 5, 2010 | 12:16 AM
  #126  
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careful tephra, there's alot of knock going on mate ! i smell danger . . . there's definitely something very wrong ! may i suggest you to load stock map and do a run and see if the same problem persist. if it is then it's for sure hardware and not the software (tuning part).
Let me know if you need a map to test out for R&D purposes. I can send you mine for testing. and yes, you need to dump alot of fuel during spool up on aggressive mivec maps.
mine is 8.8 on fuel map @ 3K rpm from 180 load onwards and AAFR is @ about 12.0 but it's back to normal after 3.5K RPM.
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Old Feb 5, 2010 | 12:17 AM
  #127  
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I sure am logging AFR

ROM and logs sent - bryan please take note of the different injector scaling, I have stock injectors ....

let me know if you need xml to suit!

Last edited by tephra; Feb 5, 2010 at 12:20 AM.
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Old Feb 5, 2010 | 12:21 AM
  #128  
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thanks E6 - i know this is very dangerous...

That's why I added 1 full point of fuel to the map... but it's still knocking intermittently (1 in 20 pulls)

Last edited by tephra; Feb 5, 2010 at 03:17 AM.
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Old Feb 5, 2010 | 07:17 AM
  #129  
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Originally Posted by GST Motorsports
Hmm that is interesting I've never seen it capped so rich with 1000cc's before.

I also never look at AFRMAP as it means nothing to me, only final real AFR.

I've never had a fuel map looking like what you posted for spool. Can you send me your ROM for that log? I'd be really interested to see it.

- Bryan
Bryan,

I can gladly send you a log and map. What is your email?
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Old Feb 5, 2010 | 07:19 AM
  #130  
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Originally Posted by tephra
So the log doesn't look terribly lean.

I just understand how 10+ pulls can be good, then BANG all of a sudden 30 knocksum

seem to me like a failing fuel system, either relay or pump...
To me at least it seems that the fuel pump is not switching over to the higher voltage outpur correctly. Unless your MIVEC map is causing it. Did you try to do a run with stock MIVEC just to see if the same occurance happens. If it does your can rule out the MIVEC most likely.
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Old Feb 5, 2010 | 08:41 AM
  #131  
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Tephra, I went back to look at my maps and logs because I am on a completely stock X. I am running a MIVEC that is modified from GST's, but slightly less aggressive by about 2 degrees less max intake advance and exhaust retard. Ever since I started tuning back with gunzo's mivec, I've noticed I had to significantly richen up the AFR map during spool for my comfort. My fuel map is at least 1 full point richer starting at 90 load compared to stock (during spool). My map ends up around 11.0 after spool. I don't have a copy of my map here to post it, but just wanted to let you know that yes, I also had to have a VERY rich fuel map during spool. I remember it dropping from 13.4 down to 12.4 down to the 11's very quickly. It's a lot richer than any map I've seen posted, but I think it's because I'm ultra conservative. As a test, try setting your fuel map in the 11.x range starting at 100 load and see if that helps.

With this aggressively rich mapping, the AFR drops into the low 11's by 3300 rpm (with a pull starting at 2000 rpms).
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Old Feb 5, 2010 | 08:54 AM
  #132  
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Originally Posted by LaXGSR
Tephra, I went back to look at my maps and logs because I am on a completely stock X. I am running a MIVEC that is modified from GST's, but slightly less aggressive by about 2 degrees less max intake advance and exhaust retard. Ever since I started tuning back with gunzo's mivec, I've noticed I had to significantly richen up the AFR map during spool for my comfort. My fuel map is at least 1 full point richer starting at 90 load compared to stock (during spool). My map ends up around 11.0 after spool. I don't have a copy of my map here to post it, but just wanted to let you know that yes, I also had to have a VERY rich fuel map during spool. I remember it dropping from 13.4 down to 12.4 down to the 11's very quickly. It's a lot richer than any map I've seen posted, but I think it's because I'm ultra conservative. As a test, try setting your fuel map in the 11.x range starting at 100 load and see if that helps.

With this aggressively rich mapping, the AFR drops into the low 11's by 3300 rpm (with a pull starting at 2000 rpms).
Like I said earlier, aggressive MIVEC settings force you dump tons of fuel to compensate.

Thus we are starting to think there might be a another table.
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Old Feb 5, 2010 | 09:34 AM
  #133  
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Maybe it's just that the aggressive tables are making tons of overlap. And this overlap is letting exhaust gases back in, making it lean. Having 35 intake advance and -15 exhaust retard should make for some good overlap.
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Old Feb 5, 2010 | 09:39 AM
  #134  
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Originally Posted by Clipse3GT
Like I said earlier, aggressive MIVEC settings force you dump tons of fuel to compensate.

Thus we are starting to think there might be a another table.
Yes, I wish I had more data to back up that aggressive MIVEC forces you to dump more fuel, but I changed everything at once (increased WGDC to help spool up too). I'll try to go back and look at my stock logs to see what AFR was like during spool with stock MIVEC. I'm pretty sure my current tune is richer than stock than spoolup.

I understand you're saying there might a table to cap AFR to no leaner than 12.88, but in this case, I'm talking about the opposite case (how rich can your afr map be?). There does not appear to be a lower limit cap on how rich the car will let AFRMAP be. In tephra's situation, it seems that it would be worth trying to richen up his spool up afr map to see how it's reflected in real-world AFR.
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Old Feb 5, 2010 | 09:48 AM
  #135  
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Originally Posted by LaXGSR
Yes, I wish I had more data to back up that aggressive MIVEC forces you to dump more fuel, but I changed everything at once (increased WGDC to help spool up too). I'll try to go back and look at my stock logs to see what AFR was like during spool with stock MIVEC. I'm pretty sure my current tune is richer than stock than spoolup.

I understand you're saying there might a table to cap AFR to no leaner than 12.88, but in this case, I'm talking about the opposite case (how rich can your afr map be?). There does not appear to be a lower limit cap on how rich the car will let AFRMAP be. In tephra's situation, it seems that it would be worth trying to richen up his spool up afr map to see how it's reflected in real-world AFR.
The lowest you can go in the AFR map is 7.4... not matter the injector size.
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