Your ECU pulling 2-3 deg in certain areas running 20+ PSI on Cali 91 octane (almost comparable to east coast 89) is not alarming. You can tune around it regardless. Is the ROM otherwise stock? If so, you could also be seeing "rich knock" which occurs when the AFRs are excessively rich.

 

Well, I never really said anything about solving my problem, I'm only simply letting you guys know what happened. Yes I can go and retard my timing and I can also not put my foot all the way down on the go pedal as well. I just think its a little disheartening to see this happen on a pretty much stock car.

 

You shouldn't feel disheartened. In your owners manual it states
that your car is designed for at least 93 octane.

Also have you logged since using 76 ?

 

Yeah, this cali gas sucks...... oh well. I ended up pulling about 6-7 degrees of timing from my map in the 6.5k-7k range.

 

If only we had 93 here, I wouldn't even think twice about using it...

Yes I've logged it since using 76 (my updates are on my first post). I think now I'm either going to:

1. Not going to drive it hard or at least not very often
2. Mix in some 100 oct or some other race fuel and then beat on it
3. Look into using some other octane booster like toluene
4. Retune my stock rom (retard timing)

 

I'm lucky enough to have plenty of 100 octane fuel stations near Pasadena.

Since I only drive the Evo for leisure, it gets a steady diet of 100 octane.

At least you have a nice IX MR... That's a good reason to be happy.

 

Have you leaned the A/F out at all yet? I havent seen a 02 voltage chart, but if you are on stock ignition I am wondering if most of the rest of your map is still stock as well? Adding exhaust components will only compound the issue and cause the possibility of rich knock becuase of overfueling. Stock fuel map and TBE resulted in 9.5:1 AFR on my MR. I know its been mentioned but since you didnt comment on it I wanted to bring it up again. A stock ignition map shouldnt knock, period. It is well retarded (i.e. ZERO advance numbers) at peak torque.

EDIT- Also your high rpm knock is at normal advance numbers, I think its probably a result of the lean spool function screwing with your AFR's there. I had a similar issue until I completely disabled it. The fact that you have no knock at peak torque with 0*, and 2 counts with 6* advance leads me to believe its probably more a combination of fuel and spark than specifically one or the other.

 

No, I haven't touched the ECU at all. My car is basically a stock 06 MR with a DP and catback. I thought adding exhaust components will cause it to be more lean? Well regardless if its rich knock or anything else, the car is still a knocking... and it sucks because I am on the stock ROM tune and have very little mods. As for now I'm pointing to the craptastic gas, as 100 octane solved the problem completely. I might try this again in the summer time when our gas will have a different blend. Thanks for your input.

 

I do not find it alarming at all. Your owner's manual says to use 93 octane gas and use 91 only if 93 is not available. Since CA does not have that gas, using 91 octane CA gas (which is even worse than 91 octane elsewhere) will cause knock and lead the ECU to pull timing to protect your engine.

That is why I keep telling people to STOP USING 91 octane and start mixing to get the desired 93-94 octane. I used to get those NASTY AFR spikes indicating a misfire when I ran 91 octane gas. Once I switched to mixing, all these spikes disappeared. Recently, I logged an Evo 8 that used 91 octane and it had the same spikes that I used to have.

The Evo is NOT like every other turbo car. It is a VERY high boost turbo car. This car needs a steady diet of high octane gas.

 

When we move back to Cali. I will definitely run Meth or ALK with conservative boost to resolve these issues or convert to E85 ....You may want to think about that...I see you are in Sacramento (probably 2 hrs. from Vishnu Tuning) -- I believe Shiv is converting some folks to E85 if you are interested.