Help me read my logs

[Scott4957]

Well I am on revision 5 with Torrie and things seem to be progressing nicely. I say that not really knowing what I am looking at haha. I get the very basics but I was hoping the veterans could chime in and let me know if I am interpreting them correctly. In reality Torrie will do all the work and likely needs no feedback from me, whatever I read and interpret in the logs will be no different then what he sees.

These two logs are an out an back, 0-110ish. It seems any knock is being caused by hard shifts as they all come right at the point the RPM's drop from the shift, is that the likely cause? Unfortunately that pulls timing and power along with it. One thing I have been noticing is right in the middle of the 3rd gear to 4th gear pull, with knock going down and the car starting to advance timing I get a spot where timing is pulled and I don't know why that happens. All other spots where timing is retarded corresponds with knock. For example in the second long at 9.4 and 10.5 seconds knock is falling and all the sudden it pulls timing, 9.4 is associated with a small dip in fuel pressure as well. I may be reading into this too much, I'm just trying to get an idea of what you guys look for as you work through the revisions. I think it was FoMoCo that posted a very clean log from many more revisions with Torrie. I'm curious how you personally gauge the performance increase over the revisions? Thanks for any assistance!

[Scott4957]

I also wanted to share what I feel was the cleanest log, this was from revision 3. Here the spark advance is not retarded through the 3-4 pull like the other logs. Its a nice smooth advance, just a slight leveling off with a knock event and then it continues to add timing. This run gave me my best 60-90mph and 60-100mph time and I can only assume it is that nice spark advance curve and no knock.

[FoMoCoSHO]

How are you gauging your times?

[SHOdded]

I do see the dropout in fuel pressure on shift to 3rd gear.  BTW, why are the data timings sometimes 1/100th apart, and sometimes 2/100th?  Shouldn't it be pretty consistent at 1/100th?

[Scott4957]

How are you gauging your times?

Times are just pulling from the CSV file in Excel, the first hit on 60, mark the time, then the first hit on 90 and 100, subtract one from the other. I'm sure its far from perfect, I was just hoping it was repeatable so at  the very least it was a way to see improvements. I moved to doing 60-90 to take out the 3-4 shift from 90-100. Seeing that nice smooth spark advance curve in rev3 compared to the pulled timing in the same area on rev5 is likely the reason I had a better 60-90/100 on rev3?

I see now that timing is pulled after the shift and then if there is no knock it starts adding timing as the rpms climb only to take it back on the shift. I assume that is normal. Just can't figure out why the timing was pulled in rev5 during the 3-4 gear pull.

[FoMoCoSHO]

Have you loaded into livelink to view the graphs?

[Scott4957]

Have you loaded into livelink to view the graphs?

Yes, that's how I see the timing being pulled, knock, etc. For times no, I was just using the method mentioned above.

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[SHOdded]

Battery (possibly alternator) and HPFP would be on my list of suspects.

[Scott4957]

I'm not thinking there is an issue, the runs where hours apart, I'm sure if I loaded the other tune it would be fine. We will see, he already has rev6 to me and I will load it today.

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[AJP turbo]

Cool id like to checkem out later...often knock sensors show activity at the shift not because of mechanical noise from the actual shift but load(boost) will spike and if the spark isnt retarded enough you can knock a little.....if your load spikes above 1.8 briefly the spark tables arent normalized meaning anything above 1.8 load the spark will be what it is for 1.8 but should be lower.....like if 1.8 load at 5k should be 13 degrees 1.85 load you would want maybe 11 degrees  but the spark tables only go up to 1.8 so u get that spark

And the increased load spike at the upshift is usually the culprit for fuel pressure drop

And a hot 3 bar tune u may be in the 1.6-1.7 load range with spikes near 1.8 or more....so u are right there i bet with torrie

And if he is using torque reductions for the upshifts..the ecu will pull spark to limit output...thats 1 way it controls tq on the shift so that could make u see spark being pulled with no knock

I highly doubt its mechanical noise from tranny causing knock...knock has a very specific sound frequency thats why i dont buy the wire mod for the knock sensor fixing anything...vibration from a rubbing wire wont do anything unless is worn bare then that's different

[SHOdded]

There's a near full-second dropout of fuel pressure starting at the 2-3 shift point.  I have seen FP drop at a shift point, just not so much.  Load was def > 1.8 during that time though.

[AJP turbo]

There's a near full-second dropout of fuel pressure starting at the 2-3 shift point.  I have seen FP drop at a shift point, just not so much.  Load was def > 1.8 during that time though.

Thats a healthy load...depending on rpm 1.85 load could be near 20 psi so yeah expect a drop in fuel pressure even at high rpm where the pump is strong..lot of boost...when my load is over 1.80 at the shift my fuel pressure will go down to about 1100 psi....i dont want it to go below 1000...thats a 50% reduction in fuel pressure from what is probably being commanded...ive gone below 1000 psi but thats like my own self imposed limit

Drop in fuel pressure with increaed load is optimal conditions for knock lol....so even if you arent running lean you can see you have maxed out the fuel system....you wont see the drop in pressure with an adequate fuel system

[SHOdded]

FP was at 750 psi, so below the "optimal" threshhold of 1,000.  Granted I have only looked at log 3 so far ...

[Scott4957]

Well when we run out of fuel I will just add meth LOL Thanks for looking guys. Like I said I have rev6 now and once loaded and tested I will get some logs from that. AJ, I appreciate the insight into how load affects fuel pressure, knock and timing. It was not something I was looking at or knew anything about.

Scott

[AJP turbo]

FP was at 750 psi, so below the "optimal" threshhold of 1,000.  Granted I have only looked at log 3 so far ...

Thats getting low....so he is pushing big boost or fuel pump is weak....i suspect his load was over 1.9 if pressure was that low....without seeing it yet....id say every bit of 20 psi