OAR deviation concern

CustomS550 said:

I've run nothing but BP up to this point

5.5 max on 91 @ 11.2 AFR @ 19.72 PSI
9.5 max on 93 @ 11 AFR @ 20 PSI

This is the thing, all figures seem to be fairly safe and standard yet it's still pulling the OAR. Could the knock sensor be picking up on other noises?

BTW, all logs are posted in the OP.

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Try a different brand of gas. Are you getting it from the same station? BP is usually decent in terms of quality, but if the station you're using is old with crappy fuel tanks or doesn't see a lot of volume then that could be the problem too. Try running it almost dry and using a different brand of fuel, like Chevron, from a gas station that sees a lot of traffic.

And yes, the knock sensor can pick up other noise. It's called false knock and would usually come from something being loose and rattling around, like the exhaust. Make sure everything has proper clearance and is tightened down sufficiently. Check both sides of the engine, the exhaust, etc.

I still haven't seen my OAR move from .96 since I bought my car. Stock tune and 9k miles

Marvinmadman said:

I still haven't seen my OAR move from .96 since I bought my car. Stock tune and 9k miles

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Yea, mine has been at .96 since day one as well haha

Well what dafuq? Might try a couple tanks with an octane additive and see what happens

Marvinmadman said:

Well what dafuq? Might try a couple tanks with an octane additive and see what happens

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I've tried Torco with Shell 93 to no avail lol. I no longer even bother with trying to up it.

Mine has seen -1 at some points with a full bottle of Lucas booster on the 93 octane tune, so it's definitely doing its job.

Spykexx said:

I've tried Torco with Shell 93 to no avail lol. I no longer even bother with trying to up it.

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Shell seems to be universally terrible in these cars. I noticed that a long time ago, and even Adam brought up the same thing several times that he'd seen in multitudes of datalogs. I would highly recommend trying a brand other than Shell and see if it improves.

I'll put it this way. I've seen gas from Shell stations that has been so poor that even race gas didn't dope it up much. That's saying a lot, and I know it probably isn't like that at every single station, but it's generally a poorer performing fuel with these cars. I'd imagine it'd have something to do with their specific additive package.

I used Shell for a while. Switched to Costco for a couple months. Now I'm on Valero. No difference in OAR

Juben said:

Shell seems to be universally terrible in these cars. I noticed that a long time ago, and even Adam brought up the same thing several times that he'd seen in multitudes of datalogs. I would highly recommend trying a brand other than Shell and see if it improves.

I'll put it this way. I've seen gas from Shell stations that has been so poor that even race gas didn't dope it up much. That's saying a lot, and I know it probably isn't like that at every single station, but it's generally a poorer performing fuel with these cars. I'd imagine it'd have something to do with their specific additive package.

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I had thought the same and strictly used Valero 93, however I recently gave Shell 93 Nitro+ a try and have learned that it actually performs better with fewer negative corrections and less knock activity. I was surprised because I've had bad experiences with Shell in the past, but as long as I stick with the newer Timewise stations and not hit the older looking ones, the fuel seems better, at least here in the Houston area.

Juben said:

Shell seems to be universally terrible in these cars. I noticed that a long time ago, and even Adam brought up the same thing several times that he'd seen in multitudes of datalogs. I would highly recommend trying a brand other than Shell and see if it improves.

I'll put it this way. I've seen gas from Shell stations that has been so poor that even race gas didn't dope it up much. That's saying a lot, and I know it probably isn't like that at every single station, but it's generally a poorer performing fuel with these cars. I'd imagine it'd have something to do with their specific additive package.

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Sadly, we don't have crap for 93 choice here. Shell and walmart. Everything else coins 91 as top premium. Very little 93, but we have E85 at like every single station lol. Maybe I should take the hint...

I also haven't found a way to find negative correction on the SCT yet for the EB either. Knock sensor does absolutely nothing. And no corrections PID. :(

Sorry for thread revival, just wondering if you sorted your issue out?
I'm curious, my OAR is stuck on -0.24 running stage 0 (some baseline diagnosis before I upgrade IC etc.). I ran the Stage 1 91 and 93 and both were at -1.0 within 30 mins of driving, but for a tank and a half Stage 0 is still running -0.24 and its not moved.

I am wondering what it takes to move the damn thing, I filled up on 1/2 empty so thinking that my previous "bad gas" is still prevalent but other than that I am stumped. I'll wait until the next tank of gas and re-load the Stage 0 and see where it goes. I noticed that when I did stage 1, it started life at -0.75 while Stage 0 started life at 0 and then adjusted from there... unfortunately the cobb website doesn't go into detail on their maps and differences

I haven't figured it out yet, unfortunately, but I did switch to using the 91octane tune again and it's better. I still hear some kind of noises at peak torque, though. At this point I'm considering taking the head off to examine further.

Please update the thread if you do. Funny, I put the Stage 1 91 Octane and my OAR is -1 within 30 min drive. Still get negative correction however, -1 is highest so far so nothing eye popping. Still, I will take the cautious approach here.

-1 is the best it gets so you're good to go!

CustomS550 said:

-1 is the best it gets so you're good to go!

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I know, however I wonder why does stage 0 only go to -0.26. while stage 1 goes to -1. I think because it starts at -0.75 I end up at -1 even though my fuel may not be -1? Does this even make any sense lol. I put all my bits on over the next week and want to make sure all is perfect before I do some better tuning

I made some normal driving logs today, seems that some of my neg timing is on down shift, and most the other neg timing is in the morning when engine is cold and the charge temps would be lower (I take it easy until I see 80C+ on Cyl head). I'll keep logging and see what the correlation is, no doubt when I get the tune they will pick it up and tune it out or accommodate safely.