Boosted E38 max timing?

[granatl]

I'm running ~11.3 PSI (max) on my turbo Camaro w/ E38 on e85 (and FF sensor). When I log a run, my timing drops off to ~10 degrees, which is about 1/2 of what I thought I could use. I have BKR off, but still get <1 degree of knock in the higher RPM's.

I wanted to know if anyone felt like sharing their high RPM/MAP timing as that seems really low to me.

[PST]

It does seem low. But if you're getting knock retard, you may be too lean.
Posting your tune and a log would be helpful.

[SultanHassanMasTuning]

could be your IAT getting high and pulling

[PST]

Sultan, he said he is getting 1° knock retard up high. I agree that the iat could be pulling timing. But that's most likely the least of his concerns at this point.

[SultanHassanMasTuning]

^a log would help for sure, most likely running lean

[granatl]

Oops. I thought I had e-mail notifications on!
Anyhow, I have a Squash return-style twin fuel pump setup. I can't "possibly" be lean as much fuel as that thing flows (and IDC are only like 60%). And my GM equivalency is 1.176 (.85 lambda). Fuel trims look good, etc. I do need to reconnect the wideband and log it just to be sure. I don't mind richening it some and then posting a log.

[granatl]

I upped the WOT timing to 17-20 degrees. This didn't have any affect on knock, so it must be (mostly) false. {BTW, I have BKR disabled}. I did "up" the EQ Ratio to 1.19 (.84 lambda) above 3K RPM.
The car is making sick amounts of torque.
Now that I'm logging GMVE in the one histogram, I see where I need to fix my VVE table. It has changed since I switched turbos.
Feel free to look at the attached log. My wideband is messed up, so ignore that.
Thanks for your help!

[PST]

Your brave to add timing as a test for real or false knock!!
Burst knock retard (assume BKR?) is just a predictive amount of timing that gets pulled on varying levels of airflow increase to prevent real knock.
Your logged knock retard, if it is truly false, is most likely due to the knock sensor gain tables. Raise them up by like 5% at a time until the false knock goes away.
Be warned though, once it goes away you will have more timing. Without a dyno to tell you what's going on, this could make or break your engine.

[PST]

You can add some good race fuel as a better test for real or false knock. If it goes away with the high octane race fuel mixed in, then it was real knock. If it stays it's most likely false.

[granatl]

Thanks! I do plan to go to the dyno in about a week and a half.

[eficalibrator]

You're still on the lean side, IMO. This, of course, ASSumes that your actual and commanded lambda are equal. Cheaper widebands are notoriously off at high load, high temp, rich conditions, right where things get "interesting" with boost. Add fuel and verify actual lambda with a reliable wideband and see what happens...

[DSteck]

Was gonna say... 0.84-0.85 is pretty lean for boost, even on ethanol.

[ingsteve]

i would try to target at least 0.80.
where is placed your wideband?
personally i had it installed on the cross of the xpipe and had target 0.85. On the road it was ok but after logging a session at Monza track i got a lot of knock at wot after 120mph.
Checking the IDC i was suspicious...then i tried logging with wideband on the passenger side first and then on driver side.
On the passenger side it was quite ok but on the driver side i was reading 0.89-0.90. Having experienced this, i matched the commanded afr with the driver side.
I don't have a dyno so i can't say if i gained or lost some power (no noticeable difference) but after that, next session logged at Monza was ok!
Of course i have a cammed NA but the concept of wideband placement is still valid. I use Innovate MTX-L wideband.

[granatl]

I'll richen it and see what the butt dyno tells me. My wideband is in the downpipe about 3" down from the turbo. I appreciate your feedback!

[granatl]

This is crazy. All I increased was the PE EQ Ratio (Alcohol) >3,000 RPM to 1.25 (0.80 lambda) and now I'm getting knock at 4,000 and 4,400 (but not 4,200).
So either I'm getting rich knock, or it was so lean before that it couldn't knock (I accidentally did this on my Buick, but I don't think it's THAT lean on the Camaro).

What's particularly strange is my LTFT have freaked out and have gone +3-10% positive where they were all slightly negative before this change. I might just need to let the car stabilize. I compared the MAF Hz table with an older file and the values match.

[ingsteve]

you need to reset fuel trim and do at least 50miles for comparing the trim. Else just look at your wideband.
KR at 4000 might trigger your knocks at both 4200 and 4400. Please see on the log the afr at 4000. If in line with the wideband you can try remove only some degrees at 4000. I hope you are checking this at leat in second or third gear. First gear the speed is very low and also the charge