This is getting on my nerves, i've posted about this before but i've got a decent log to show now. I've taken out 3-5 degrees of timing out of peak torque. I thought I cleared everything up until tonight I got a good audiable ping. I've got new plugs and plug wires too.
Anyone know how to clear up the lean spot durring transition?

 

That graph is pretty but does not show us the real values for the knock area.

We would have to know AFR, IGL, IGT, RPM, relative boost, plugs, and engine mods.

 

sorry, forgot that not many people have this program. The left column are actual values with a times x value.

AF being 11:1
RPM 5673
Boost .57 bar
IGN lead is a solid 16 flat once full boost is reached
IGN T is a 5
Knock is 100


Non-seq stock twins
stock plugs
stock ign
8mm wires
DP, stock cat, stock intercooler, exhaust. 850 primaries and 1600 secondaries, upgraded fuel pump.
stock ebuilt engine by Pineapple racing. 1k miles.
This car also has water injection.

 

Where's this lean spot? Your data clearly shows injector transition and there is no lean spot there according to your AFR graph.

That knock is out there, why is it that you are at 16 deg advance flat but you said you removed 3-5deg at peak torque? If you did retard leading ignition without retarding the trailing you might have very little split there, just a guess. Since the knock is happening at only one spot on the log (I always look at max knock so be sure you are not looking at averages) try retarding just that one cell to see if it clears it up. I have found that under low boost tuning that there's quite a bit of knock around peak torque, especially with a ported motor, if you are running anywhere near default map timing. YMMV

 

well hrm, you got me on the flat thing. Maybe I accidentally loaded an old map. I'll check into it. Anyone know where I can get stock mazda timing values? I've tried finding them before with no such luck.

And by the lean spot you can see durring the transition that the AF moves from 12 to 13 and then tapers back to 12

 

The timing you listed is in the same ball bark (mine was 17 for 8psi and 15 for 10psi) before I went single turbo. Your AFR is richer. I run 12.1 there even now.

I suggest you verify that the correct plug wires are going to the correct coils and correct plugs.

 

Chuck,

his AFR is over 12 at that point where the knock is occuring, it's in the low 13's before that under boost.

Aeka,

I think you might be too lean, plus, if you are plotting averages and there is any misfire then the max AFRs are way up there. I looked at the plot a bit closer and if I am reading the scale right you are running near 13 AFR during boost before the knock event, that's lean.

INJ transition doesn't appear to be a big thing to me as injector transition is during non-boost area and it only gets richer during injector transition then goes right back to the curve of falling AFR. Perhaps you can remove some injector overlap to get rid of the rich spike during INJ transition.

 

I must be missing something, sure looks like his A/F was around 11.

I don't see anything in your plot to suggest detonation other than the single high knock value. My guess would be something else created the knock.

 

plug wires are correct. Thea leanest spot in boost is 11.9:1 and the knock area is 11:1. Plus I have water injection.

 

I must be seeing spots then, if 100% is 11.05 AFR then what is the AFR at 110% to 115%?

If you do have correct water injection percentages then even the AFRs I was seeing(or imagining) would be fine, but saying WI doesn't mean it's at the right ratio, but I'll assume you got it right.

With everything ok fuel wise and timing wise perhaps you have a wiring gremlin. Really, if your tuning is spot on then it should not just arbitrarily knock like that every once in awhile. It would not seem to be fuel since the AFR is not indicating an injector hiccup or some fuel issue, if the logged ignition advance is not picking up anything, ... thinking ... are these average values or max values or min values or is every data point being plotted?

 

OK, then verify that the leading and #2 trailing connectors to the coils have not been swapped.

 

Those aren't percentages. just add a decimal. 100 is 10.0:1 120 is 12.0:1


Hrm, I should check on this. Have you seen cars run fine with these plugged in backwards? I should have time this weekend.

 

I gotta put my crack pipe away or something, maybe I've been working too hard of late.

Car will idle and cruise fine with those wires crossed but it should knock like hell under boost.

How old is your wiring harness and what condition is it in? I would suggest you post your .dat file and your map so we can take a more indepth look at what's going on. Feel free to PM me and I'll give you my email addy if you prefer to send the map and log that way.

 

Some have done it. The car will run like normal for idle and cruise and will ping under low boost.

 

I don't think it is related to trailing firing in the wrong spark plugs. If it was, the average knock reading should be much higher. I do notice that the Inj Time was continue decreasing in those area (which should still be increasing) and that the Inj % stays constant. I think the a/f #'s are incorrect and the car was actually running much leaner than it shows. 42% duty cycle seems way too low for 7psi of boost at 5.5krpm.

 

Just go add 10% fuel on the PIM voltage map for above 0 boost and start tuning your AFRs.

 

ok ive started fresh with my tuning again. Got my ign for 13psi at around 14 with a 10 split. I've set my pim vs RPM to get some decent A/Fs of 10:1 I havent touched my fuel correction map or base map yet. I havent been able to re-create the knock.

The only thing i did differently between starting this tune and the previous tune was that I didnt mess with the pim vs rpm before. My old map i adjusted everything in the fuel correction map. One thing i found odd was that my idle didnt smoth out while adjusting the pim in the 1000 rpm range, but it smothed out once I fattened up all the other RPMS, I found that strange, ill ask about that in another thread.

I'm starting to wonder if this was because of the shitty 91 octane fuel I get around here.