Experimenting with Octane Adjust Ratio (LOR) settings in SCT

AJP turbo · March 12, 2016, 02:02:40 PM

Fomo, I'm going to try a little test for you sometime this weekend. I'm going to pull 10 degrees timing and change the "min allowed learned octane for knock learning" from -1 down to -2

I expect to see my LOR to go below -1 in that case....Currently in my tune I sit between -.80 and -.96

I think you maybe looking too deep into the LOR stuff....I treat it like a LTFT but for spark...I don't think you have to worry about changing those values and the knock strategy, that stuff is separate as far as the total amount the knock sensors can add or pull and also degrees per second that the sensors can add or pull. And at what load and speeds the knock sensors are allowed to add and pull.

If you are at constantly at -1 LOR then I'd say you have 1 of 2 things going on or both even. Your fuel octane is higher than you think and or your spark curve in under advanced.

If I leave the -1 value alone and keep advancing my spark curve then It should never get to -1.

If I pull timing and lower the -1 to -2 then the ECU will continue to scale the spark curve until it's happy with the amount of knock it's seeing..To me it's kinda like the threshold limits that are in the STFT's for the 02 sensors......They are around +-25%....You could just use whatever fuel you want and have a bad fuel curve and mix fuels and let the 02 sensors adjust but that's not ideal...a well tuned car will have STFT's less than 5% and less than 3% if you are good otherwise the LTFT's will make a long range scaling

So I could pull all this timing then let the LOR make the adjustment but I'd rather have the base spark tables closer to where they should be

FOMO did torrie activate some of the "end user options" for you? You could always add a couple degrees and see if your LOR raises and goes closer to 0....Didn't you say you are consistently at -1?

FoMoCoSHO · March 12, 2016, 03:43:43 PM

Yeah it is pegged at -1 and doesn't change.

No, the full options in the handheld are not unlocked.

I can make a global timing change but nothing by RPM.

AJP turbo · March 12, 2016, 03:54:45 PM

Quote from: FoMoCoSHO on March 12, 2016, 03:43:43 PM
Yeah it is pegged at -1 and doesn't change.

No, the full options in the handheld are not unlocked.

I can make a global timing change but nothing by RPM.

Add 2-3 degrees globally and see if that raises your lor

FoMoCoSHO · March 12, 2016, 04:39:32 PM

Quote from: AJP turbo on March 12, 2016, 03:54:45 PM
Quote from: FoMoCoSHO on March 12, 2016, 03:43:43 PM
Yeah it is pegged at -1 and doesn't change.

No, the full options in the handheld are not unlocked.

I can make a global timing change but nothing by RPM.

Add 2-3 degrees globally and see if that raises your lor

Slow and steady is how I roll, I will add 1 and if I don't see a change I will move to 2 and then 3.

AJP turbo · March 12, 2016, 04:51:35 PM

Quote from: FoMoCoSHO on March 12, 2016, 04:39:32 PM
Quote from: AJP turbo on March 12, 2016, 03:54:45 PM
Quote from: FoMoCoSHO on March 12, 2016, 03:43:43 PM
Yeah it is pegged at -1 and doesn't change.

No, the full options in the handheld are not unlocked.

I can make a global timing change but nothing by RPM.

Add 2-3 degrees globally and see if that raises your lor
Slow and steady is how I roll, I will add 1 and if I don't see a change I will move to 2 and then 3.

Yeah nothing wrong with that....but being that you are pegged at -1 tells me your fuel mix is good...but like burger king have it your way

FoMoCoSHO · March 19, 2016, 08:55:05 PM

Added 1 degree of WOT timing, still no KR activity or OAR (LOR) change.

Go for 2?

AJP turbo · March 19, 2016, 11:10:16 PM

Quote from: FoMoCoSHO on March 19, 2016, 08:55:05 PM
Added 1 degree of WOT timing, still no KR activity or OAR (LOR) change.

Go for 2?

Just thought of something.....hold please

Looking at the knock sensor strategy. I don't think anything over 4000 RPM and or 1.5 load I don't think will affect LOR/OAR

So FOMO You added 1 degree to WOT only. once you exceed 4k and or 1.5 load it won't apply any recorded knock activity to the LOR/OAR so you could keep adding spark to WOT and I don't think it will change anything....Except if you keep adding you should start seeing knock retard at wot....So you should reach a point where you keep adding spark but the knock sensor will just keep pulling it out

SHOdded · March 20, 2016, 04:03:51 PM

bump

FoMoCoSHO · March 27, 2016, 07:45:51 PM

Added another degree at WOT, saw a max of .8 of Kr for a brief second, so basically no change.

Oar still pegged at -1 peak boost was 17 PSI

Raised rev limit to 6400 as well.

FoMoCoSHO · March 31, 2016, 12:23:56 AM

So I added another degree of WOT timing yesterday (3 total) and raised rev limit to 6500

Took her out for some beatings and hit the REV limiter on the first WOT upshift from 1-2

I didn't see much KR till a rough high RPM downshift and was rewarded with a 6.8 spike.

Today however, beatings resulted in perfect upshifts and .8 KR max, still saw some advance during parts of the run.

Peak boost of 17, OAR still unchanged.

The tranny behaved with no nasty downshifts. Adaptive learning doing its job?

ecoboostsho · March 31, 2016, 11:32:19 AM

Interesting stuff! It could be adaptive learning or maybe it was just a fluke blip of Knock? One question I do have is while the strategy/tune may not actually affect LOR directly over 4K RPM / 1.5 load I wonder once the LOR value has changed if it affects the WOT timing?

In other words if you have a LOR of -.5 I have always assumed that would factor in to the calculation of the total timing you would see at WOT but maybe I'm wrong in my assumption and the car just relies on the Knock Sensor to pull timing (which I wouldn't like)...

Thanks for experimenting

AJP turbo · March 31, 2016, 01:39:52 PM

The way i see it...the lor/oar value affect all spark...but the knock sensor readings above those those load and rpm will not change lor/oar....so knock sensor supervises the actual spark at wot

FoMoCoSHO · March 31, 2016, 02:56:18 PM

With questionable fuel quality a possibility and my tendencies to play amateur chemist with my fuel, I'm glad the knock sensor is still in charge above 4500.

AJP turbo · March 31, 2016, 06:40:44 PM

Ive thought about changing the scalars in the knock strategy so the knock sensor reading above 1.5 load and 4k would contribute to the oar value...but the oem did it that way and im not sure why....not that the oem cant be improved on but i just dont know what it would help

It would probably lower my oar and scale my spark down if it used the knock retard readings from my wot....but i dont always get knock retard with how i have it now.....so id rather keep the spark scaled more aggressive and ride the edge and if i get knock at wot let the knock sensors do what they do

AJP turbo · April 03, 2016, 10:28:14 PM

Tried anyway,...I made the knock sensor contribute to OAR up to 1.7 load from 1.4 and to 5800 rpm up from 4k....So basically anytime the knock sensor reads it will contribute to OAR.....My OAR went from .-96 to -.81

So cruise and light throttle the fact that I never knocked made my OAR max out in the good direction and it scaled some more spark in for me....And any KR I got above 4k and WOT wouldn't bring my OAR closer to 0 but now that I let the areas of KR during WOT affect OAR it took it closer to 0

Kinda cool....So I could add some spark to light throttle but if it causes KR it may raise my OAR more and scale everything more retard then I would have to add a little more spark to WOT to get it back to where it was.....That's why the knock sensors are awesome....they will add and retard as they see fit to ride the edge of knock making the most power all the time...I wanted to see my OAR raise a little to see what I was leaving on the table since I had the min allowed OAR at -1 like stock...being at -.96 I wasn't sure if it wanted a little more...Now that it's -81 I know I'm at the limit for my fuel