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Discussion Starter #1
I've made some threads about a problem with my bama tune having a knocking problem. While my first 87 performance tune had audible knocking, the revised fixed so I didn't hear it, but data logging still showed knock occurring at times. Well today I filled the car up with 93 octane shell....it took 10.44 gallons. That plus the remaining 5.5 gallons of 87 gives me approx 91 octane. I drove the car 15 miles to make sure the 87 left in the fuel lines was consumed and data logged again. I'm still getting readings of up to -5.24... Which I believe is how much timing is being pulled.

But wait...I just realized something though,....I get little blips here and there,..but the big ones are when it shifts! It's pulling timing when it shifts! That's what's going on...it pulls power when it shifts.
I figured I'd share my eureka moment.
 

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The way the PCM is setup, it will always be pulling timing because it is set to keep advancing the timing until it hears knock and then pull it back.

As far as the retard on the shift, that is torque management and your tuner can set it up not to do it in your tune.
 

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Is this the crackling sound some of us were describing in a similar thread.

After reading your post, I went and tried it out and sure enough, the sound only comes at a shift point during WOT. If I can verify this, I'd like to get AM to fix it.

The question is, Is there a loss of performance due to the fix?
 

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Discussion Starter #4
I have since put about 400 miles on the tune and I am going to log again tonight, then I am going back stock and log what happens there. If its similar I'm putting the tune back in and never thinking about it again.
To answer your question, yes from the first to this third revision, I seem to have lost some top end.
 

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As far as the retard on the shift, that is torque management and your tuner can set it up not to do it in your tune.
Its really common for high performance automatic cars to ping/knock/crackle/whatever when shifting. I had an LED tied into the knock sensor circuit on my old car and it used to often go off only when shifting WOT.
 

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Discussion Starter #6
Ok, so I logged again and had a highest reading of -3.69 KR on my 87 tune with 89 gas in it. Now there where several blips from -.39 to -1.5, and two around the -3.69 where it shifted WOT. Then I went stock. Absolutely 0, except for one -2.05 at a shift. Now maybe there where no other blips because it was a fresh reflash....I don't know.
 

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Have you talked to BAMA about it?

Just a minor suggestion. You should keep all of the conversation history of this topic in the original thread. Somehow you've managed to start 3 new threads about the same issue. People need to jump and search from one thread to the other to understand what you're talking about when you say "I've finally figured it out".
 

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Discussion Starter #8
I have not talked to bama about it. To be honest, I think they think I'm a PITA at this point, even though I think I'm getting good data. I think that it's saying something that bone stock is showing a spike of KR.
Your probably right about the thread thing, I just want to keep interest alive in my findings, and not let the thread die.
 

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Honestly, I don't think enough of us are educated enough on the topic to really add anything here. While the concept of engine knock can certainly be considered common knowledge, the reading and data you are describing is completely foreign to me and most other members.

Perhaps if there was a guideline that could be posted to help us understand this, we might be able to contribute. I would certainly be up for learning more about this especially since my BAMA tunes should be arriving any day now.
 

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Agreed. Here's the thing. If you're really hearing flat out engine knocking, that is an issue anyone should be worried about and immediately lay off the gas to figure it out. The noise is unmistakeable from other noises. The problem I always worry about with the cars I modify though is that I'd never hear it over my loud exhaust, intake and supercharger especially at high rpm's. Where I'd be more likely to hear it is before or as the computer is making changes when I'm mid throttle, high gear on an incline, putting the car under a lot of load.

An ECU pulling 2-5 degrees of timing is not uncommon. The sensors are there for a reason. I used to tune my Hondata ecu on my Acura and I spent countless hours chasing a couple knocks that were being picked up as the car switched from the low cam to the high cam and vtec kicked in. I though for sure it was going to blow my motor and had something to do with the load it was under going to the high cam. Eventually I ended up on a dyno 3 states away, Evans Tuning, in PA. I asked Jeff about it and he laughed. He said it was truly nothing more than the noise the engine made switching from the low cam to the high cam. He said half the tuning exercise is determining what's a real knock and what's being picked up from other areas, ie engine shifts, low to high cam etc. Even wheel hop through the chassis can show up on some sensors.

I think you're going to pull your hair out chasing this down and never get to a point that the ecu doesn't pull timing unless it's running a valet tune.
 

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Discussion Starter #11
Honestly, I don't think enough of us are educated enough on the topic to really add anything here. While the concept of engine knock can certainly be considered common knowledge, the reading and data you are describing is completely foreign to me and most other members.

Perhaps if there was a guideline that could be posted to help us understand this, we might be able to contribute. I would certainly be up for learning more about this especially since my BAMA tunes should be arriving any day now.
Actually, I'm not at all educated about knock except for what I am learning as I go. I had some exposure to the evils of it when I had my mazdaspeed3 and motors where popping because of it. This I what got me relatively paranoid about it. I know a boosted motor is a lot more susceptible to damage from it than a n/a motor. From everything I have heard, and speaking to a few tuners, mild knock retard under -2 is normal for this motor, and going stock and still seeing this confirmed this to me. I'm also certain that aftermarket tunes are set up to push the timing up to that knock point much more aggressively than ford has it set to.
 
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