Timing transition causing ping?

[HQforme]

I ran with the values in the tune file you posted and it's now logging KR every hit of the throttle, up to about 4 degrees, then lets it back in. See attached log.

2nd gear stab from a steady state (the initial style of driving that i thought created ping) is around 33 seconds in, pulls 4 degrees. No audible ping. So now i'll try reducing those low throttle total timing figures so it's not at high 30s when i stab the throttle.

Small top gear pull at 43 seconds logged no knock but only gave me 16 degrees total when it should be 24? Slightly longer top gear pull at 1:24 again logged KR on hit but timing seems way too low, even with the retard, compared to what my spark tables are at.

So it's improved yet confusing for another reason. I'm learning at least.latest log no ping.hpl

[SiriusC1024]

Are you running the tune I posted with all changes or just knock sensor values? I had adjusted IAT spark modifiers, so maybe that's why there's improvement. If so it's time to pull spark from the main table to get rid of KR. The timing pulled is Maximum Knock Retard vs RPM (PE).

[HQforme]

Just the knock values for now as i wanted to ensure i was seeing their direct benefit before any timing changes, which i now know i am. Not sucking oil is a huge improvement too! Haven't had any good, long pulls to clean the carbon out yet (had a look at no1 piston today).

I did find that max retard under PE table so assumed that was the case, thanks for confirming. Confused as to why it commanded such low timing on that longer 3rd gear pull. I actually felt the car respond sluggishly then pick up when the timing returned. When i whacked the throttle it only gave me 8 total (with 4 removed for knock) so a commanded 12 at what should be 21.

[SiriusC1024]

Big KR when hammering it and dropping gears. Try the Burst Knock Retard settings, too. In the 3rd gear pull KR is happening when the throttle is let off then rapidly re-applied.

[HQforme]

Ah ok, so it was a double whammy of retard. Cheers. I'm not dropping gears on any of those pulls, just a fast roll in to full throttle. From what i read burst knock is a preventative timing reduction on transient throttle so i may soften it slightly if needed.

[SiriusC1024]

Are you sure about smooth throttle movements? KR at time 0:33 and 1:24 with what looks like rapid throttle application. Yes burst knock is a preventive reduction in spark to prevent knock from occurring during a transient. Not sure if you had it on for this pull or still disabled.

[HQforme]

I'm not stomping the throttle like a petulant child but yes it is a rapid application so we'll call it that . Burst knock seems to be effective in that log as it's below specified timing after each rapid throttle transition but before logging any ping.

[SiriusC1024]

Main thing is you aren't eating up pistons anymore

[HQforme]

Main thing is you aren't eating up pistons anymore

Abso-bloody-lutely

Do you recommend turning off burst knock so that as i take timing from the table it's only showing true knock (if any) and timing retard, then once it's all sorted put the burst knock back in? I know a degree or two is expected. I'll just aim not to have it hitting max PE KR.

[SiriusC1024]

I'd put on burst knock like in the tune I posted and reduce timing where normal KR occurs.

If timing was removed with burst knock disabled it would lead to sub-optimal timing on the main tables. You may find that it takes a fair bit more than a degree or two from the base table to prevent knock during rapid throttle opening.

Burst knock is good to have enabled. The magnitudes I assigned are going to keep the engine alive without robbing power.

[HQforme]

Ok, so i'll try make sure not to be heavy on the throttle to avoid burst knock oming into play while i try fine tune, rather just progressive sweep on the pedal so it adheres to commanded values and see if they induce knock then adjust main timing tables to suit. Being OL that's just high/low octane; i can't recall which one it defaults to. I ensure those and base in gear or P/N are all matched anyway.

Thanks once more for you ongoing help. You've been concise with your info. Takes so much of the mystery out of it.

[SiriusC1024]

You're welcome. Let me know if you need anything else.

[HQforme]

Ready for round 2 my super helpful friend? The case of the mysteriously altering idle AFR, false knock and missing WOT timing?

After waiting a bloody fortnight for my starter solenoid i got her running today. Fired right up, idle was fat. Back to the "old" 14.6ish indicated on the AFR, which fouls plugs, smells and stalls. Still, drove around, got to full temp, did a pull (logged on MPVi2), came home, connected laptop, live tuning VE table to fix the idle afr, fired up perfectly to what i set it in the tune. 15.8ish, no smell, plugs beautiful last time i checked after extended idle. Sigh. Only difference i can see was in IAC counts. Both at hot, steady idle. Not sure if it's a cause or a response. When you compare idle in the long log vs idle in the short idle log you can see difference in counts all over.

I've seen a vid on making a PID that duplicates hi octane spark table, logging max retard values and pasting them as a subtraction into the spark table as a means of eliminating light throttle knock. Is this valid to get rid of the smaller (1-4degree) KR moments by taking that timing off the main table?

Reason being, reading the log as to why it felt so sluggish i see 2-3degrees KR for a few seconds at light throttle (44 secs and 1:54 in log). Then when i give it a second gear pull to 6000 (1:20 in log) i only get 16degrees total and can't find where it's gone in any modifier table. Is it burst knock lagging too long? Should be 24, burst knock is 8 at that point but i can't see a time factor. I can see burst knock logs as a value on transient throttle but doesn't show in the KR bar on th eleft of the "dashboard' on the scanner. Yet on the transient to WOT i can't see any numbers logged for retard at all. Just a low total.

No pinging but at 16degrees you'd expect that. It's very fat up top (11/1) as i'm doing all my timing first and pulling some out of light throttle cruising as recommended.Started back up at correct afr.hpl

I've been informed there's multiple PIDS to log KR so i'll try find them all and see which one is robbing me.

I miss my carbies! Haha

[HQforme]

Ignore the "latest no ping", this is the log Latest no ping but sluggish.hplCurrent best tune primary kock reset and idle spark tamed.hpt

[HATEHPTUNERS]

I'm enjoying reading through this post and hope that the information keeps coming. Very informative so far. You, the op, are getting some really good information-as well as the rest of us! Thanks guys!

[HQforme]

Cheers. I'm trying to explain my concerns in laymans terms to help other newbies just learning to tune and he's doing a great job of not getting lost in my waffle and identifying core issues.

[HQforme]

Weeeeeeeeell, it was burst knock. Zerod out the table that had 8 degrees across the board and got all my timing back. No idea why it was remaining on so long?

Today the car was just behaving like an absolute arse. Rich at idle again, not responding to my live tuning changes. Then it started a bit of a hunt and would catch at a super high rpm idle with 45degrees timing! I think the timing drove the rpm. Long story short i reverted to my old tune (with all the knock sensors off) and it started behaving again. Still a little rich at idle? It's like the thing is trying to fight me back to stoich even though my trims are turned off, as is adaptive idle etc. And there was noise in my TPS again. So now i've reduced total timing to 22 and will get fuelling right and listen for pinging. Then try introduce knock sensors again.

Final mystery, on a 2nd gear pull to around 6000 again (it goes to 7200 at the drags but i'm on the street here) with throttle wide open, it momentarily dropped rpm, i felt it in the car, timing rock solid, fuel solid, can't see anything, just wound down 350rpm for half a second then came back.

I sometimes wonder if the ECU isn't just a bit shitty with life?

[HQforme]

Final update for closure.

Ran the car last week. PB'd at [email protected]. Pretty bloody happy for 3350lbs, stock stroke aspo LS1, driven to the track with full exhaust! 25degrees total. Happy as Larry. Essentially, all my pinging was the oil in the intake but through the course of this saga i've learned a lot. The car still fights me at idle trying to attain stoich, seems to vary between my set AFR and stoich, but it's the least of my evils right now.

[SiriusC1024]

I'm glad it's running right. 11.1 is really moving! Where did you end up with knock sensor values?

[HQforme]

Well i got very sidetracked. Haha. Short term i have a street tune at 22degrees total and a track tune with 26, all in slightly earlier using octane booster. So far that's seen me through ping free. But i really do need to get them going in a more gentle fashion than the last time.

As i've gotten everything more consistent i'm now obsessed with working out why, first start and drive, even to full temp and a long run, it runs consistently about half a point richer on AFR. Once i stop the car and hot start it, bang, right back to where i tuned it with open loop. I'm looking for a startup table related to temp where maybe a decay factor is wrong and it's not actually zeroing out. Once started hot, that table isn't in effect. Well that's my layman thinking anyway.