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Learned Octane Ratio (LOR) Gauge in Torque

Started by ecoboostsho, April 16, 2015, 01:47:38 PM

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ecoboostsho

Learned Octane Ratio (LOR)

Not being able to understand what the LOR (A gauge we have in the Torque App) was doing or even if the formula was right (I was pretty confident it wasn't) was driving me a bit crazy so I decided to do some experimenting.  This is a long post so I apologize in advance but stick with it – I think this is a good gauge to have working when all is said and done.

First a good refresher on what the LOR gauge is "supposed" to do would be in order. I believe it is approximating the octane level in your gas - not through a sensor - but by monitoring knock (and maybe other?) parameters in the ECU. If it sees it knocking away then it assumes you've got some bad gas or you put in 87 Octane and it adjusts the timing to compensate by multiplying the LOR number by the appropriate timing table and thus reducing your overall timing. This should result in less knock and a happy motor.  A great analogy (Thanks Larry!) is that the LOR is sort of like the Long Term Fuel Trim in that it learns over time from the Short Term Fuel Trims and comes up with an adjustment value.  In this case however the Knock gauge is the "real time" feedback loop and LOR is the learned value over time that will try and prevent knock in the first place.

The Experiment:

I put the car back to stock as I was planning on running different Octane fuels to try and understand the results. Needless to say I didn't think throwing 87 octane in with my 93 tune was a great idea. I didn't really like doing it stock but I did this to try and figure out how it worked. 

Step one after going back to stock was to watch the values change as it learned and I did this with 93 octane and a mix of E-85. I calculated my mix at about E16.

Timeout: The other piece of background information that I want to insert here was the Cobb tuning article posted by another member that indicated how the numbers should work in theory...a value of -1 was said to indicate the "best" possible ratio you could achieve. If the value moved back toward 0 or to +1 then the car was ultimately removing timing to avoid Knock. It used values from part throttle and full throttle. They call it "Octane Adjust Ratio" but I believe it is the same thing...I may even rename the PID in Torque. http://cobbtuning.zendesk.com/hc/en-us/articles/204049644-Octane-Adjust-Ratio-OAR-

Back to the experiment: So as I stated above I started with E16 so I could get the car to a theoretical -1 and let the car go from there. After tracking the points and doing some math it was clear that the numbers were signed binary numbers but thankfully Torque handles this. The formula I came up with was:

(Signed(A)*256+B)/16384


Custom PID is 2203E8

(If anyone needs assistance in where to type this in just PM me or refer to the Torque PIDs thread in this same forum.)  You will need to DELETE the existing gauge off of the display and THEN edit the PID or you will get weird results.

I used the Digital display gauge and one important point (if using that gauge) is to override the default # of decimal places and use a value = 2. Just press on the gauge on the screen and go to "display configuration" and select "decimal places". If you don't do this it will start rounding on you and you may not realize it has changed at all.

My car started "learning" and moved toward -1 and eventually achieved that value after a few hours of driving the car. I did get some part throttle knock and at some point the value actually "settled" at -.98 for about a week and then finally back to -1 after about a full tank of gas.

Next up: 87 Octane

I put in 10 gallons of 87 Octane with about a ¼ tank (roughly 5 gallons or so) while not exactly 87 Octane combined I'm guessing it was probably in the 89-90 total range. Well my results were immediate and dramatic. Once I used up whatever 93+ was in the lines the car immediately started knocking during part throttle acceleration on a freeway on ramp. I saw a constant 4-5 degrees of knock at part throttle and then just couldn't take it anymore (i.e. I chickened out) so I backed off the throttle. The LOR instantly went from -1 to -.75 and the car immediately felt slower (I'm not kidding I could tell...) but it was no longer knocking nearly as much when attempting the same type of acceleration. I only drove it for a few miles like this and expect it to continue to move towards 0 but time will tell what happens and I will update the results as I get them. I can't imagine what kind of stupid gas it would take to make it positive number but I don't know that I want to find out. The good news is that it appears very sensitive and reacts right away to save the engine in conjunction with the Knock gauge.

After driving some more on the blended crappy gas I can report back that the car briefly tried to go from -.75 to -.83 and that lasted until the next highway on ramp run under part throttle and it shot back to -0.67 when I hit 4 degrees of knock.  I can definitiely say the gauge is working well.  So far any knock that hits 4 degrees or higher seems to cause a fairly immediate adjustment to the LOR gauge.  The car seems to tolerate up to 3 degrees of knock as "normal" and doesn't make any immediate adjustments to the LOR value.

Drove the car for a full week with the 87 Octane.  I just put 93 octane back in it and after a few trips the LOR shot to -0.99 which is almost perfect.  It did have a little of the 87 left in it so I'm running something a little less than pure 93.  Car is still stock but will be retuning shortly.

I will probably try 91 on my 93 tune to see if the LOR value is indeed utilized by the "tuned" ECU.  I can't imagine it isn't but you never know...

So in closing I highly recommend you remove the previous Learned Octane Ratio gauge (Also accept my apologies since I figured out the first one based on another Scan tool that apparently had it wrong as well).

Also these are all based on my research – I welcome any constructive feedback or data points you might experience so we can improve this and/or verify that this is currently "correct". I am 99% more confident in this formula than the last one however, that doesn't make it perfect. Just understand that there ARE situations where you could get readings that indicate "bad gas" or "Low Octane" that might actually be other problems. What I mean by that is if a knock sensor is going bad it may show excessive knock even on 93 octane fuel. In this case the problem isn't the fuel but something with your car – but it will show up as a LOR that is moving toward 0 or +1 instead of -1.

Happy motoring!

PS. The car sucks on a stock tune and 87 octane...
2013 White SHO w/PP, Gearhead Tuned, 3 Bar, 160T, Plugs...Mess with the Bull and you'll get the Horn. :)
Previous 2011 Tuxedo Black SHO w/PP - 12.89 1/4 Mile

SHOnUup

2011 Sterling Gray Metallic SHO non PP,
12.4211 @ 110.28 Livernois 3bar tune & CAI,
Added since...PPE catless Dpipes, Megan coilovers, Powergrid adjustable end links, and EBC slotted rotors and red stuff pads.
Tommy Designs grille with carbon fiber hydrographics, fender badges and fog bezels hydrodipped also, tinted windows, head & taillights, debadged trunk with all chrome plasti-dipped, black calipers, obdlink mx scantool running torque pro on 7" tablet.

ecoboostsho

Thanks Rich - I am anything but that...but I appreciate the comment.
2013 White SHO w/PP, Gearhead Tuned, 3 Bar, 160T, Plugs...Mess with the Bull and you'll get the Horn. :)
Previous 2011 Tuxedo Black SHO w/PP - 12.89 1/4 Mile

SHOdded

Thanks for putting this up, I think quite a few people will have something to "learn" from this gauge about their fuels :)
2007 Ford Edge SEL, Powerstop F/R Brake Kit, TXT LED 6000K Lo & Hi Beams, W16W LED Reverse Bulbs, 3BSpec 2.5w Map Lights, 5W Cree rear dome lights, 5W Cree cargo light, DTBL LED Taillights

If tuned:  Take note of the strategy code as you return to stock (including 3 bar MAP to 2 bar MAP) -> take car in & get it serviced -> check strategy code when you get car back -> have tuner update your tune if the strategy code has changed -> reload tune -> ENJOY!

FoMoCoSHO

Awesome work!

I'm curious to see if my 20% blend of e-85 and meth get us below -1.....

Hopefully I read that correctly, lol.

ecoboostsho

I suspect you won't find it going below this value but it would actually be awesome if it did!
2013 White SHO w/PP, Gearhead Tuned, 3 Bar, 160T, Plugs...Mess with the Bull and you'll get the Horn. :)
Previous 2011 Tuxedo Black SHO w/PP - 12.89 1/4 Mile

sunwolf

Quote from: ecoboostsho on April 16, 2015, 03:51:31 PM
I suspect you won't find it going below this value but it would actually be awesome if it did!
If it doesn't drop below -1 does that mean that there is no benefit? Maybe 2 gallons is too much without special tuning?
2014 Taurus SHO Black Performance Pack LMS tune 3bar tstat downpipes
2008 BMW M6 Convertible SMG
2008 F-150 XLT 4x4 5.4L
2011 F-150 Ecoboost Crew Cab 4x4
2012 Lincoln Navigator L 4x4

ecoboostsho

#7
I wouldn't necessarily assume that I guess. The car may still add timing due to other factors that don't directly influence LOR.  It would be interesting to see, but I've gone as far as I am willing to go in the e85 testing dept.
2013 White SHO w/PP, Gearhead Tuned, 3 Bar, 160T, Plugs...Mess with the Bull and you'll get the Horn. :)
Previous 2011 Tuxedo Black SHO w/PP - 12.89 1/4 Mile

wasinger3000

Can't wait to see how this acts with meth in the tank. Thanks for the great work!
13' SHO, Non-PP, Tuned by Torrie, Meth injection, 3 bar, 170* stat, custom axle back exhaust, Prosport Boost gauge.
15' F150 Lariat Sport, all the options, 3.5L Eco. (fiancée ride.)
13' GTCS, will be missed.

ShoBoat

 I can personally say that it works as advertised. I tried it in my SHO as I was working through some fuel quality issues. And I decided to try it in our Explorer (wife only uses 87) LOR was at -0.08 lol. Thanks for the work on this!


Sent from my iPhone using Tapatalk
2012 Pearl White CTS-V Stock
2016 Fusion Titanium 2.0 EB Stock
2013 SHO Black on Black (Gone) PP, Unleashed Custom Tune, 170 TStat, SP534 Plugs, 3 Bar, Airaid Intake, PPE catted downpipes, Corsa Cat-back, H&R Springs. Focal 165KR Front Stage,2 JL W6 10 with Focal 800.1. 12.62 @ 110 mph.

FoMoCoSHO

Quote from: sunwolf on April 16, 2015, 04:48:18 PM
Quote from: ecoboostsho on April 16, 2015, 03:51:31 PM
I suspect you won't find it going below this value but it would actually be awesome if it did!
If it doesn't drop below -1 does that mean that there is no benefit? Maybe 2 gallons is too much without special tuning?
The 2013 and the 2015 jumped about 40 WTQ and 25 WHP according to Torque, and before anyone says Torque is inaccurate...

The 2013 ET dropped from 13.70 to 13.31 so I feel pretty confident the stock tune can make good use of the octane.

I'd say 4/10ths is a pretty respectable gain and it's the cheapest mod ever.

Hopefully the weather will start cooperating and we can see what the 15 does.

glock-coma

I tried the updated lor gauge today. I'm  at -1.0, but I'm due to fill up soon. We'll see if it changes at all.


2010 RCM non PP
K&N panel filter
sp534 @ 30
unleashed 93 performance+boost 3bar
more to come.....

2010 red candy metallic non PP 402B
AJPTURBO 2 BAR Tune Stock 14.1@100.3 / Tuned 12.83@107.7
K&N panel, RX OCC, Sp-534 @.30 Tint 50%F-35%R BOV bypass
1997 SHO silver frost (sold)
1990 SHO triple black 5-speed (saved my life)

Larrylu

Great work ecoboostsho!  I'm really liking having this gauge on my main display screen. Awesome functionality.
2010 Loaded, Non PP, Steel Blue Metallic, Livernois Stage 4+, Blacked out grill, Nexus 7 Tablet running Torque Pro

ecoboostsho

Thanks Larry!  I ended up putting the tune back in and am still trying to work my way back to full 93 Octane (I am getting close) but my LOR is actually still at -0.93 so I am guessing it is either still learning (It's only been about 4 days of occasional driving) or my Octane isn't up to speed yet as I had a little of the 87 Octane left in the tank.  Either way I do think this gauge is actually working well so far.  I will definitely be interested to see what happens with those running some high Ethanol blends.

As I've said before it should be a "boring" gauge...until it isn't and then I will be glad I have it if I start seeing knock.
2013 White SHO w/PP, Gearhead Tuned, 3 Bar, 160T, Plugs...Mess with the Bull and you'll get the Horn. :)
Previous 2011 Tuxedo Black SHO w/PP - 12.89 1/4 Mile

SHOnUup

Put straight 93 in yesterday, no corn. LOR still reading -1. No excessive KR, less -kr in normal driving for sure though.

Rich

Edit: 93 has 10% E in it
2011 Sterling Gray Metallic SHO non PP,
12.4211 @ 110.28 Livernois 3bar tune & CAI,
Added since...PPE catless Dpipes, Megan coilovers, Powergrid adjustable end links, and EBC slotted rotors and red stuff pads.
Tommy Designs grille with carbon fiber hydrographics, fender badges and fog bezels hydrodipped also, tinted windows, head & taillights, debadged trunk with all chrome plasti-dipped, black calipers, obdlink mx scantool running torque pro on 7" tablet.