LSJ-T: Calculated or Real KR?

[jrsmith]

I just started to notice KR in my last log. Never seen it before so not sure what's the deal, although I did just change to colder BKR7E plugs.

Car is LSJ with forged stock compression pistons, K04 turbo with mbc maxing out around 20 PSI.

I'm wondering if this could be calculated KR as I haven't "zeroed" out the burst knock retard tables. I'm pretty new at this though so i'm sure i'm missing something.

Time stamps in particular I am wondering about are 8:56:44:246 and 8:56:47:025 during WOT.

5 (20 PSI) (33T) IDC.hpljoel turbo test.hpt

[cobaltssoverbooster]

false knock is not a topic for the lsj. it is possible it could be but this ecu reports direct sensor input as kr. Chances are your detonating.
I don't know how your adjusting timing when your not even logging cylinder airmass in the first place. You need to make two histograms to properly watch ignition advance and retard.
1) start logging cylinder airmass in grams you'll need it for both steps 2 and 3.
2) make a new histogram call it advance. for the y axis duplicate your ignition tables airmass axis and for the x axis duplicate the ignition tables rpm axis. for the logged parameter select ignition advance.
3) make a second new histogram and duplicate the axis setup from step 2 but this time change the logged parameter to kr.

this will allow you to view your kr in respect to your ignition advance table which makes corrections much easier. i would like to note at your first time stamp that you register roughly 234 kpa when your at 6* kr and if you reference your max allowed retard at 4400 rpm zone you are roughly around 122 kpa which allows 8* retard max. if you pulled 6 out of the 8 and your current ignition advance reading states you made 14.6* advance that means the total value listed in the advance table was roughly 20* advance. That puts you at .68 grams of airmass at 4400 rpm in the ignition map. chances are that zone needs to be finessed a little before you work with the kr settings. if you every exceed the 200 kpa axis in the max knock table then it will default to maximum listed value which in your case is 8. Do not set this table to zero or it will shut the kr system off and you will poof a motor; ask me how i know.

After reviewing other things in your log file i notice you really aren't setting the scanner up to best your benefit. the fuel trim histograms dont match your ve table setup and the maf histogram doesnt match either. Setting these up correctly would help you fix your wide error in fuel trims which i can see swing between -25 and +40. keep in mind the ecu only has 20% trimming capacity so anything registered over 20% is a monster of an error. Since you set your maf sensor to full range priority i suggest you try to settle your maf sensor in first.

the best thing to do is run a similar to stock ignition file and settle your fueling issues out. 90% of ignition issues in the lsj can be related to fuel system issues. dont forget to disable defco when tuning your trims in.

[AP83]

I've never seen false knock in my LSJ-T, even when it still had the Heaton on board. It's always been real.

I'm on mobile, so I can't look over your tune right this second, but I'll give some general advice.

Massage the timing table, make sure it's smooth. The engine likes a smooth transition when spark changes.

Make sure the plugs are gapped right. I started out with a .033 gap and wound up at .028.

What's your octane? 93 takes a lot less timing on a LSJ-T. I struggled to run 13 degrees and 17psi on 93, now I run 16 degrees and 23 on E30, moving over 50lbs of air, not a lick of knock.

As CSSOB said, you need to be logging your timing advance and KR to have any idea what the car is doing and what to adjust.

You need to make sure the fuel mixture is dialed in using a wideband before tuning timing. Nice flat PE curve, nothing leaner than 0.82 lambda.

My car is MAF only with the LTFT's shut off. If you have the MAF tuned correctly, the STFTs can handle it just fine, plus you don't run into the car wanting to add fuel when the LTFTs are lean.

Setting the scanner up correctly is vital to tuning a LSJ-T correctly.

[Area47]

shut off burst knock and try again.

[jrsmith]

Thanks everyone for the replies, I see I have a lot of work to do!