It worked!

It's been about 3 days since I flashed the last map using my "new strategy" and it seemed to work.

During normal driving, I didn't have any more knock in "Feedback Knock Correction* (degrees)" and "Fine Learning Knock Correction* (degrees)". Yippee!! :-)

But during highway driving when I did several WOT and hard driving, I did have knock from -4.22, -3.16, -2.11, -1.05:



Should I be concerned? Hmm.. I'm not sure.

Right now my boost is set to 1.2bar. I've did some WOT to pull some dyno figures from airboy's spreadsheet. I'll share that in my next post.

New strategy

Ok. Here's my new strategy now. I've got 2 quite good maps from ravenhil.

1. 20080530_OL9b_ravenhil_cracked.hex
- reasonable fuel economy
- smooth but has knock

Here's his email response:

The zipped file works! Okay first thing, your injectors are dangerously saturated above 6000 rpm. I do not know what ebcs you are using, but try to reduce target boost and wastegate duty cycle at 6000 rpm onwards to 1.2 bar. This will allow your injectors to stay within the safe operating limits. Otherwise, you could toast your engine when you WOT next time. If I remember correctly, Alyvn did mention that you usually drive in a binary mode. That is, either foot off or WOT. :)

MAF scaling is a lengthy process. Not exactly impossible to do, but takes a lot of time to do it right.. There are several different approaches to take when tackling MAF scaling but in your case, 70mm APS CAI is a bit too much for the ECU to make corrections. I believe that the AF Corrections will exceed the learning parameters of the ECU. You will need to calibrate this with a wideband O2 sensor to make it work. I do not think it is realistic to achieve this by emails.

However, the AFR values in the given datalogs seems just about right. You are not running dangerously lean.

The meth injection is a cool device. However I am not sure if you are running with or without meth. It seems like it isn't since there is no effect on engine load and boost. BTW, your car seems to hit target 1 bar of boost pretty late. It is obvious that your AVCS isn't tweaked as well.

I have re-worked the ignition timing tables for you so reduced the values at certain points, increased it at others, to give your car fuel economy when cruising, and safe power at WOT. This timing map is based on the one that you are already using so as to keep within safety parameters, Also, i tweaked the tip in enrichment to enhance throttle response. The AVCS is my last touch. You should be able to hit boost sooner now.


2. 20080530_OL9b_ravenhil_cracked_v2.hex
- fuel economy not very good
- much less knock

His email:
The latest map I sent you had my own tweaking for MAF scaling as well as an implemented anti-knock strategy. This kind of stuff took me a long time to do and usually, worth a princely sum in any pro-tuner shop. And I doubt if they are as single minded. Nonetheless, let me know some feedbacks on the latest map. You should see IAM 16.

My new strategy:
1.Combined both maps:
Take 20080530_OL9b_ravenhil_cracked_v2.hex and replace the MAF scaling table from 20080530_OL9b_ravenhil_cracked.hex.
2. Monitor knock
3. Use mickeyd2005 knock spreadsheet to fine tune the timing table.

Findings:
1. There's much less knock now, in fact very minimal.
2. When I use mickeyd2005's spreadsheet. Here are some results:






Note the logs for the above were done using normal driving (< 3500 rpm and no WOT).

After thinking it thru, I end up taking off 1 degree from my current map. I'm naming this "20080726_timing.hex"



Let's see how it goes.

No it doesn't work :-(

The changes above still does not resolve the knock. :-( See below.. there must be something else?

Comparisons..

I've compared the categories:
Fuel
Timing
Knock
MAF

And I can only find the foillowing changes in the knock section (besides Advance Multiplier Initial = 16):



The changes are for:
Feedback Correction Range (RPM)
Fine Correction Range (RPM)

The top window is the original value and the one below are the changed values.
Let's see if these changes are the ones that will solve my knock problems!

How much timing is enough?

Ok some bad news... I've done 3 rounds of adding timing to where I experienced knock but it still does not help :-(

I'm going to analyse ravenhil's rom and see if I can find out anything.

Add more timing

I think I will add more timing first (analysing ravenhil's rom will take me some time) :-)

Here are my changes (20080530_OL9b_ravenhil_cracked-masv1d_basetimingonly.hex):

Add Add Add!!!

Ok, here are the logs from last night's changes in base timing. (I added more timing)
As you can see below, the knock has actually reduced.



Inspired, I added more timing to the areas which still had knock (20080530_OL9b_ravenhil_cracked-masv1c_basetimingonly.hex):


It seems to help:



So should I add more timing? Well, you know what? ravenhill had sent me a second version which he said will ensure I never have any knock. I checked the logs for that rom and true enough .. no knock. I think I should analyse his rom changes :-)

Add or reduce timing?

Here's the result of the changes applied to my base timing table:


As you can see, my "Feedback Knock Correction* (degrees)" has actually increased i.e. it has got worsed :(

I did a search on NASIOC and someone said that increasing timing could actually help:
"FYI, on my 02 WRX, I have found that I had to increase the timing quite a bit below 2000 rpm all the way out to 1.2 load column. I think what is happening is the mixture does not have enough time to burn, so when it exits, it is still burning which ignites the incoming right away. I can drive in 5th gear at 35 mph with no bumping, shaking, etc. I can also do a 5th gear pull from 1200rpm and have it nice and smooth. I'm still working on it though, but the result has been increase the timing.

what helped me figure it out was making a 3D plot of g/min divided by rpm(based on your map table). it bascially gives you the g/rev, then you can divide(or multiply) it by your timing value in the map. it will show you spots that don't quite line up with the overall trend, the problem is you don't know what the trend is, or where the ends shoudl line up, so you have to keep that in mind. I think you will find your low rpm, mid load range is off.

my thinking is that if you keep the rpm consant, and increase the load...then the charge will need less time to burn, so lower timing is needed. if you keep the load constant, and increase the rpm, it needs more time for a complete burn...thisonly makes sense for closed loop where the AFR is constant. I have not done the physics research to see if this increase is linear or not, but I assumed it was and have had good results. Once I get it lined out, I will start to increase timing and see what happens. I also zeroed my CL/OL delay and made everything below 2000 rpm run in closed loop...

one more thing, take your log and graph only those load/rpm points where you have FBKC or FLKC. I make an X/Y scatter plot with rpm in the y axis, load in the x axis, and then scale the axis to match my timing table values. I did that to your logs you posted...and you can see exactly where you need to focus."

Here's the full thread:
http://forums.nasioc.com/forums/showthread.php?t=1498977

Ok, I'm going to give that a shot. Here's my change (20080530_OL9b_ravenhil_cracked-masv1b_basetimingonly.hex):

My first try at Base Timing mod

Ok, here are the 2 logs which I took. Noticed the "Feedback Knock Correction* (degrees)" values.

The first log actually had more knock with 4.22 and 2.11 but I'm only taking the ones with 4.22:



The second set only had 2.11. I think I was using SPC's petrol which is better than Petronas.





I've made the following changes to my map (I'm running ravenhil's v1 map for me as a base - more than on that ROM in my later posts).


Let's see if this helps to improve the knock in my low end.

About logging to tune knock

It's been awhile since my last post. Ok, the reason is because I'm really lost with all this knocking thing going on. :-)

It turns out that to tune knock, I only I only need a few parameters. Here's what Rene mentioned to me:

"For checking about knock events through driving all you need to log is, Engine Speed, Engine Load, and Fine Learning Knock Correction, and Feedback Knock Correction. If you see any activity in either Fine or Feedback column find that are in the base timing map and lower the timing. Usually you will not find a data point of the exact engine speed and load so it will usually be a 4 cell area that you are looking for."

The thing is, I've also been logging "Knock Correction Advance" and thinking that a non-positive value means that I have knock! This is not true!

"The Knock Correction Advance table gets its names because that is what the ECU adjusts for knock. There will always be a correlation between Fine Learned and Feedback Corrections. For example if your KC value should be 10 for a given load and rpm and either Fine or Feedback go ahead and pull timing of say -1.4º then you will see your KC value drop to 8.5. Keep in mind that you IAM is at 8 so every value in your Timing Advance table is only being used at 50% of its value because of the way the ECU calculates timing. Let me know if you have any other questions."

Ok, this makes it easier for me to tune the ranges which have knock! :-)