LNF e47 knocking

[08VRSS]

So...... I checked my local E85 content and it has been 70%, crap e85. Haven't had any problems recently until a few days ago I logged all the way home and had knock 3* on cyl#2 and #3 on a 4th gear pull at 5000rpm and above until i let off at 5800rpms due to traffic. The car has alky/water injection 50/50 and running e47, didn't honestly think knock would be a problem at 22.5* timing and 24.5psi.

Side note, before all of this happened, it was full 85% so now I have been taking a little fueling out due to the lower e85 %, about 7%-8% less on the injector constant, this got the fuel trims good again.

Today did another log and it knocked again on only one cylinder as shown below. I even lowered timing to 21*, still pissing me off, it never knocked before at high rpm like that and it has me nervous. Any suggestion? Could it just be shit gas?





Heres my log from a week ago on a more aggressive tune, same gas:

[codename Bil Doe]

Can you ul or link to your tune?

[08VRSS]

Well, I pulled my plugs and they looked perfect, I was convinced it may have been false knock, so i upped the boost just a tad, and made a ton of 3rd and 4th gear pulls on the highway to redline a few times. No knock at all. GD picky LNF lol. The Intake temps were about the same, i was also thinking heat soak of the FMIC, but temps only rose 17* on a really really long 4th gear pull to redline, so i guess its ok.

[codename Bil Doe]

MikeM and I have found that you can get a lot of false knock. These sensors are pretty shitty. I can make the same run back-to-back-to-back without touching the tune and be knock free or get knock. Focus on the plugs and sort out what is fake versus real.

The only other suggestion I can give you is to make absolutely sure every table is smooth - cams, PE afr, DAL, PID's, you name it. ANY sharp transitions and you will see kr on the logs. Also, don't forget to clock your knock sensors. I think it's pretty clear that the LNF/LSJ/LHU use knock as a catchall for any potential concern of the ecu by reporting it as knock.

[cobaltssoverbooster]

the sensors are awesome...i purchase them for use with standalone's all the time.....like i said before the ecu is garbage. there was a way to program this ecu that would be a 1k times better but no. gm got with bosch and said no lets go the hard way.
the sensors are fine you guys just need a way to calibrate their input. also false kr is not cause by the sensors all the time with the lnf ecu.....any time the ecu removes timing on its own to pre-correct an event it thinks is coming, it registers it as kr.

i purchased a knock sensor listening device and ditched the factory controlled kr a long time ago....iirc around late 2009

[codename Bil Doe]

Yup, mentioned that. KR is a catch-all for the ecu including when it doesn't pull timing. KR is almost used as a warning light for potential future events.

CSSOB - I'm assuming you're saying you left the stock sensors? Otherwise, they show 12° kr with no signal. I just choose to ignore. You know from plugs and tunes when you getting real knock versus fake. Bring back old school plug reading, people!

[cobaltssoverbooster]

no i re-coded mine in multiple areas using hex editor...the knock sensors being deleted caused no problems for me.
i also adjust tb size for a 85mm conversion, and adjust 3 other tables you cant see. i dont know the names of them i just know two helped big end power, one of which helped shift loads too, and the other gained me an additional 1 mpg on a 4 tank average.
there is more in there but not much.

[T-Man]

no i re-coded mine in multiple areas using hex editor...the knock sensors being deleted caused no problems for me.
i also adjust tb size for a 85mm conversion, and adjust 3 other tables you cant see. i dont know the names of them i just know two helped big end power, one of which helped shift loads too, and the other gained me an additional 1 mpg on a 4 tank average.
there is more in there but not much.

I'm sure you have but just asking anyway. Did you ever email support about these and their location? One would think that with simply 'handing them the keys', they might look into whether or not it's a quick and dirty update for the LNF crowd?

FWIW, I have my Max KR table set to zero.

[cobaltssoverbooster]

no i haven't shared my findings since gmtech left