Help me solve my -KC issue please

[mattg]

and E85.

[mattg]

Since the last installment of my saga I replaced all timing components, so I can confirm that I'm not a tooth off on timing. I've also had 2 other Subaru mechanics listen to the car while I rev it through the RPM range. Both said she sounds healthy.

 

No remarkable oil usage, no smoke.

Sometimes she idles like a sewing machine, sometimes misses a little.

Power delivery doesn't feel so good (WG and boost control issues plus Jarrad has dialed timing way down at shift landings trying to diagnose my KC issues) but when it all comes together the car feels strong.

 

Yesterday I filled up the car w/ Chevron 92 + a bottle of Lucas fuel treatment and pulled some logs.

 

1. WOT in 5th gear on the highway - clean

2. WOT 4th gear shift to 5th - clean

3. 2nd - 5th ~ 1/2 throttle - ugliness

4. WOT 2nd - 3rd - ugliness

5. cruising in 3rd. KC both times I give 50% throttle input.

 

And we cap it off with an ugly LV.

 

I don't really know what else to do at this point. I just ordered a GMS inlet yesterday. Once installed I'm going to take the car to PDX so Jarrad can look at it in person. The plan is to pull the turbo, port the WG and change the comp. housing to STi style. Then retune for pump and E85. After that I plan on driving the bitch and not worrying about it. If she blows up some day so be it. I'm at the end of my rope with this and just want to enjoy my car.

 

The only thing that will piss me off is pulled timing. Maybe just unplug the knock sensor and enjoy?

romraiderlog_20100413_165510.csv

romraiderlog_20100413_165555.csv

romraiderlog_20100413_171725.csv

romraiderlog_20100413_171812.csv

romraiderlog_20100413_172516.csv

[mattg]

Maybe it's time to go back to a stock weight crank pulley? It's just strange this would effect my car and not the countless other running a LW crank pulley.

 

It's also strange that the high load pulls in gears 3-5 are almost always clean.

[NSFW]

3. 2nd - 5th ~ 1/2 throttle - ugliness

Not really. Those nonzero numbers in the FLKC column don't indicate that you're knocking. They only show that you've crossed into an RPM/load region where the car has seen knock before. It's very hard to tell what's actually knock and what's just a learned correction, unless reset the ECU before every pull. Or - and this is much better - log "Knock Sum" instead of IAM & FLKC & FBKC. It's a number that increments when the ECU sees knock (or thinks it did). So in a typical log it will be solid column (for example) 8s, and then in one row it increments from 8 to 9 and that's where the ECU heard knock.

 

It's near impossible to get rid of FLKC completely. I tried that, by pulling timing every time I saw knock sum increment, and that just left me with ~4 degrees less than I had been running and it didn't knock any less often. If I can get a few pulls with no knock, I consider it good.

 

I look for two things:

 

1) Repeatable knock. If it knocks at approximately the same RPM-and-load more often than random noise would explain, that's worth tweaking.

 

2) Compound knock. When the ECU uses FLKC to pull timing, it pulls 1.4 degrees per knock event. If you see more than 1.4 degrees being pulled, then you know it pulled some timing and then it knocked again. This is worth fixing.

 

Your LV shows compound knock between 2600-3200 RPM and 1.1 - 1.35 load. So I'd pull a couple degrees from there. The other cells that have 1.4 pulled from there, I'd just take notes, reset the ECU and do a few more pulls. If you get FLKC in the same cells, make an adjustment. If you only get FLKC in different cells, then it may or may not matter. Take notes, reset, do more pulls. If a pattern appears, fix it. If no pattern appears, then don't sweat it.

 

High Octane fuel - We added a whole bottle of Torco and the car still had the -KC issues.

If by "still had -KC issues" you mean that the FLKC column showed negative values, and you did not reset the ECU before this test, then that experiment didn't show you anything. You may have just been seeing knock corrections that the ECU learned before the Torco was added.

 

It would be interesting to reset the ECU, add Torco, and do a bunch more logging. If you see no knock then you know you have a tuning problem. If you see just as much knock, then that would suggest a noise problem.

 

You might see random knock even with Torco - I haven't tried Torco myself yet but I suspect that the ECU hears false knock once in a while and be surprised if Torco or even high-end race gas really cured that problem. The interesting thing would be seeing how much difference you get in that overall frequency of knocks. Like number_of_knocks divided by number_of_pulls.

[mattg]

Thanks for taking the time to post. I'm a goof, I though I was logging FBKC, doh!

 

For now, I'm going to stick with my plan of getting the new inlet installed then taking the car to PDX so we can get this all ironed out. I hope to have some good results to report in the next few weeks.

[fishbone]

Interesting to spot another PDX tune so off the deep end as far as AF scaling is concerned. Mine also showed -15% correction and I am willing to bet it was above that percentage.

[mattg]

Mine was off so badly because of boost leak(s) I assume. The values are much closer now after my FMIC install.

 

MAF will be properly scaled soon. Just received my inlet today. That is the last piece of the puzzle before heading back to PDX for a retune.

[Spec B]

Bumping this up..did this ever get resolved?

[compsurge]

 

This sounds like my current, on-going issue as well.