What AFRs should I aim for under partial throttle? I know there was some real know in that log. The actual spikes where knock ADC hit 200s was real.

 

I shoot for 5 psi a 12.5-13 then 12.5 at 10 psi and by 15 psi 11.8

 

Wow, those are 'high' values in the threshold table (knock load in yours). Are you still capturing actual pre ignition events with those values? Also a significant increase in the multiplier. Did you change either of the adder tables?

Yep, you get into the 9's for part throttle spooling. I can even improve the knock by leaning out from 11.5 to 12.5.

Raptord, thanks, I see the octane line in evoscan now. Just never went down that far. I have a ton of logs I did over lunch, I am putting together with some images.

As Jamie and JCSBanks point out in the above linked threads, my knock too, is kind of irratic. Sometimes 9's and sometimes nothing, and then 3's. It makes it difficult to work on, but trying to tune it out has been pointless, even on 100 oct, so I am getting to be pretty sure its noise. Now the trick is how far to adjust the knock tables and what method to use.

What method did you use to arrive at those values in the tables John? Did you have a session that goes until MBT, so that you identified the max timing and then adjusted the knock tables to zero out knock sum? Or did you use a DetCan setup and tuned until you heard knock and then adjusted the knock tables to zero out knocksum just before actual pre ignition?

 

^ That. I also go with that basic slope, and modify according to if LS is disabled or not, and with what intensity its set at. I tend to set it up slightly leaner without LS enabled.

 

Its only 125 load (theoretically 125kpa) so its not that high. If it were capped at 159.4 it turns it off, knock control still works well with it set like that. I dont recommend those settings for those that dont know how to tune an Evo or dont already have a good idea of where timing needs to be.

/disclaimer

 

OK this may seem backwards, but I believe I can derive the knock as mostly not actual pre ignition even by going from 100oct to 91oct. From 91 oct to 100oct it was just not conclusive as a reduction, but not an elimination, but still a difference.


This is a 100oct tank showing the maximum values. More 'knock' in cruise and this example at least is as bad as any example I ever had on 91 oct. A couple of counts on the end of peak torque.


This one is 91 with a few decent pulls on it also showing maximums. So comparing this to the above 100 starts to identify octane is not helping. Not only that, based on these numbers its actually backwards. This is actually only supporting the comments JCSBanks made in the other thread, that the behavior is slightly unpredictable, and in my case very much so. As I was pulling timing to get rid of it and richening up too, the results got better, then worse, and back.


Lots of 2s as a maximum...where is all the knock?


Here you can see lots of cruise data that results in these 3s.

For the above all of the knock threshold tables have been set back to stock. Ironically in that entire session of 91 there was effectively very little knock. That is driving me nutty, because if I only had 2s and 3s I wouldn't even be posting an issue.

The ROM with the 100oct is actually slightly richer with the knock I am talking about, and I have tons of 91oct logs prior to that with similar knock (other threads as well)
I will post the excels in a bit.

 

I go a bit leaner than that. These are my rough targets:

PSI	AFR
0	14.7
5	13.5
10	12.5
15	11.9-12
20	11.6

 

fireroasted. i'll take a look at your logs tomorrow. long day. stayed after work to help the boss pull tin of a harley and it wasn't the most fun. want to help you out as much as possible. and to answer your question about det cans, I've read good reviews about these and they should show up this week hopefully. The company is called Phormula and they are based in the UK. I ordered mine last week and was told they wouldn't show up til the end of Feb however they'll be here Thursday according to FedEx.

My octane level is up to 98! I'll work on leaning out my rom a little. Hopefully that helps. LS is Disable btw

Aaron would you recommend running the multiplier you pictured? I'm not sure if 19 was high enough for my noise, however I'll lean my car out regardless.

As always you guys are awesome for helping.

 

You really improved knock by leaning the motor out?

 

Short answer: yup

 

Yes, too rich will sometimes induce knock. Not sure of the combustion chamber physics, but it has to do with flame front stuff.

You will also read here that too little timing can send you on the way to knocking as well. The orderly combustion of the gases in the chamber and the reciprocating speed of the engine all need to line up nicely to produce the most efficient extraction of 'work' from the energy in the fuel and air. Step over the line or too far back from it and you will get knock.

If I go to 10s I will induce knock counts. Well, in my previous stock engine where the knock sensor was predictable and I tuned from it. With this setup who knows, I could have 2 counts and then 15 and nothing has changed.

 

EvoScanDataLog_2013.01.29_12.27.44.bin

EvoScanDataLog_2013.01.29_11.24.49.bin

EvoScanDataLog_2013.01.29_11.13.47.bin

.bin to .csv

Here are the logs from today. All on 91 with all the knock values I could check in my version of evoscan. I have somewhat of information and data overload on this, so I will just put this up and see if it sparks interest in more data. Again, today ironically the 91 oct produced relatively little knock compared to my normal issue, and that has been one of the difficulties with this. (10s, 2s, 5s, all in back to back pulls on the same road in the same cells)

 

Damnit, my previous posts with logs sucks. Looking through those you would think I essentially have no knock with stock knock sensor settings on 91.

Just to make sure you guys see the actual scenario, here is a log on 100oct with 9s and 8s in the cruise load. For these logs I didn't record any knock values except knocksum.

change the .bin to .csv
EvoScanDataLog_2013.01.20_17.12.13_100oct.bin

 

Yes there is such thing as "rich knock." Definitely work on leaning out your fuels.

 

Wow man.. I just read through all 4 pages of this thread, and you are running in to the EXACT same problems I had. I tired everything to verify it wasn't real knock that my car was having. In the end I determined it was indeed false knock, and just dialed back the knock control settings and left the car on a super conservative very safe tune. I ended up selling it shortly after because I wanted to buy a house, and the guy that bought it has had nothing but perfect luck with the car.

I had some similarities in my setup too.. I had a BR short stubby BS eliminator kit, as well as some GSC S2 cams. Aside from all of that, I was doing 10:1 comp 2.1L on pump gas, and had fully built head, etc... I had so many variables, it drove me nuts for a long time!

I am a very big advocate for stock ECU tuning on these cars, but for me when you get to the point you are at and I was at, I almost feel safer with the idea of running an AEM or similar unit to be safe. I don't feel all that comfortable with dialing back the knock sensor and having the car run fine under the circumstances. One thing can change, and your car actually starts knocking and the ECU doesn't see it because the knock filters have been played with and it's only a matter of time before it pops.

I wish you the best of luck, and if you need any 1-on-1 help, feel free to PM me.