After analyzing a few of my logs today, i noticed that when the Octane Flag from my EvoScan (v.97) data logs read anything other than 100 I experience some high knock counts (7-9)...

What causes the Octane Flag to change? How is this calculated?

Below are two datalogs....both done with the same FLASH, under the same conditions, done today with the same fuel in the tank (91 oct)....one holds the Octane Flag of 100 all the way with very minor knock (max counts of 2) and the other one starts with Octane Flag 100 and goes down to 98 (max knock counts of 9)

 

Octane flag changes when you get => 5-6+ Knock.. I believe. When it changes it begins to revert to the lo-octane map.. interpolated.

 

so why would i have barely any knock on one datalog and then knock counts of 9+ all in the same day and only occur when the Octane Flag changes?

 

If this was true then why don't i have any knock here down low with an Octane Flag of 96 but then i expereince knock up high as the octane flag is increasing?

This has to be something else, not something to do with knock...

I am trying to iron out my knock, but its kinda hard to do so when the octane flag changes and it causes high knock counts when it moves out of 100 to a lower number...

 

You're in different load cells.. I would have to see your actual ignition map to see what your car is trying to run (timing wise)..

One sample for example:

TPS..RPM....KNOCK..TIMING..WBO2..LOAD
100..5500..5...........6...........11.08...253.18
100..5500..0...........8...........11.03...233.92

You'll notice one log you're running a load of 253... at 5500 RPM

The other you're at a load of 233 at 5500 RPM.. this will result in different timing being ran, even though you're at the same RPM.

You may have to run less timing in one cell on the ignition map.. to cure this.

 

As your car begins to see 0 knock when WOT the Octane will slowly rise up. As you can see from this log you attached.. 96 to 98 octane, your octane IS rising until you begin to see the higher levels of knock, then it goes back down.

This is the ECU's way of correcting knock. Your Lo-Octane map should have lower timing and richer AFR's so your ECU can look to those in case of high knock.

Keep toning down your ignition timing when you see high levels of knock.. and it'll soon go away =)

 

What exactly are these load cells??? i saw in the ECU Flash tutorial that it is boost dependant???

 

First, you should probably read this thread..

https://www.evolutionm.net/forums/sh...d.php?t=201146

Then read the Engine Management / Tuning forums..

https://www.evolutionm.net/forums/forumdisplay.php?f=98

Plus the ECUFlash section in there..

You'll learn all that you need to modify your vendor flash to your liking, good luck

 

Thanks man....i got it all figured out now....thanks again...

 

No problem