jcsbanks

I think I've found the octane number on the Evo, and I want to involve the community in testing it across different models, different mods, different fuels. If I've got it wrong then I'll smile, eat humble pie and move on

By default it is initialised at 255 after an ECU reflash or ECU reset from pulling the power to the ECU.

You can datalog this value at &H27 in Evoscan by a custom request or changing the data.xml file.

Let me know if it makes sense on your car. No time to test further as my wife wants my attention for furniture shopping

I suggest that the ECU interpolates between low and high fuel and low and high octane #2 maps as per this value.

jcsbanks

&H3D16 on JM8859-13,14,15 looks to be the 8 byte initialisation table. At your own risk you may want to alter this area to another value and see if &H27 matches afterwards Now I seriously have to go out with the wife

AlwaysinBoost

iTrader: (17)

if I knew how to modify the program to log that parameter I would, but when it comes to this 'teknologicial komputer' stuff I'm all thumbs. Sorry.

laakness

iTrader: (12)

This is good info, hopefully MalibuJack finds this thread and may be able to verify it.

MalibuJack

iTrader: (5)

I'll try to check it out this week..

MalibuJack

iTrader: (5)

I can't correlate that data with any other map though.. Its possible that particular table only exists on the Evo 9.. But with a string of 8 ff's it pretty much turns up everywhere in all the roms so its not unique enough to find other roms..

The Octane number is a short term value, and therefore probably only stored in scratch ram, the parameters used to determine how to traverse between the maps is probably something different..

At some point we'll get a tool to examine the scratch ram (the area where the rom is copied to and altered as the car runs, where the information for fuel trims and whatnot are stored) once we can do that in real time, we should be able to do real-time tuning, map tracing, and even faster logging..

But unfortunately I can't match this data to anything I have.. Give it some time, I just started looking at it..

I don't have a 9 to experiment with.. and I'd be cautious about doing anything but logging this value and somehow seeing if it changes and under what conditions.

MalibuJack

iTrader: (5)

you can add this to the data.xml file in one of the dataset items if its a good value and want it used perminently, or you can just add it to the program as a custom request temporarily...

Attached a new DATA.XML file to put into the C:\Program Files\EvoScan\EvoScan v0.8\DataSettings directory...

Log it and see if it actually does anything..

MalibuJack

iTrader: (5)

And FWIW, there should be a load site value also.. If someone wants to go through all the request id codes.. If you can find that, it'll make all of this alot easier..

andenbre

iTrader: (4)

After work today I will try that address in my 9 and let ya know what i find tonight. I will be logging on my way to a wedding so it may be late.

andenbre

iTrader: (4)

where can I find a list of the request codes. I was just trying some sequential codes based off existing known requests and was not able to find anything.

MalibuJack

iTrader: (5)

The ones defined are in the data file.. I would search the internet for the eclipse GSX codes if you want to find different ones, odds are their similar..

andenbre

iTrader: (4)

cool I will check it out.

jcsbanks

I've been datalogging this and it fits like a glove. Whilst you don't need to do what I did and reprogram your initial value (which we only know the location of on the 9, those of you that are seeing persistent high knock sums, and dareisay 8 or 9 degrees in the early midrange on 93 octane with any decent boost I would be expecting to be running lower than 255. If you have similar low and high octane maps I expect you'll be continuing with higher knock sums on your logs because you've effectively disabled or dramatically reduced the effect of the octane value.

Let's see if the data from these cars fits the above...

From logging the octane number it doesn't seem to have more than one number for different load and RPM ranges thankfully! It had also gone from 217 to 255 by the time the oil was properly warmed up from cold, but then when I drove it hard it stayed there whilst running knock sums of 1 or 2 sporadically.

dudical26

iTrader: (17)

bump for update

andenbre

iTrader: (4)

I have hit up to 4 counts of knock in hot weather (95* intake air temp) and 93 octane, timing pulled and boost reverted to either map 1 or 3 but that # stayed at 255