Still Knockin'

[tatasta]

Well, I am at the end of my rope. Still getting KR while rolling on the throttle all the way to WOT.

For reference, I am using EFI Live and custom operating system COS5.

I can stand on it from a stop or stand on it at a given speed and generally won't get any KR but gradually increasing load (as in the attachment), I get it often.

I dropped the timing values in the high octane spark table by 4-5* and will still get 4* KR. The highest is always 4*.

I have NEVER heard the knock or any type of valvetrain chatter, ever. I have to wonder if it is real or some type of resonance.

I have attached some images to review.

Thanks for any help

[Aloicious]

Well, I am at the end of my rope. Still getting KR while rolling on the throttle all the way to WOT.

For reference, I am using EFI Live and custom operating system COS5.

I can stand on it from a stop or stand on it at a given speed and generally won't get any KR but gradually increasing load (as in the attachment), I get it often.

I dropped the timing values in the high octane spark table by 4-5* and will still get 4* KR. The highest is always 4*.

I have NEVER heard the knock or any type of valvetrain chatter, ever. I have to wonder if it is real or some type of resonance.

I have attached some images to review.

Thanks for any help

I JUST read you post over on LS1tech, heh. do you have that log file you could post up? its kinda hard to tell from those screenshots, but it looks kinda goofy, I wonder if it is a false knock, or bad sensor type problem.

[GAMEOVER]

Have you tried to richen up your AFR @ WOT? Command PE? Tables B3618 & B3647
12.90 AFR is a little lean for my taste....

[tatasta]

Yes Sir,

A couple different logs comin' up!

Thank you!!

The two Version 3 logs are from the tune posted in the original post. The other is from a recent tune.

I feel like I am chasing a ghost. I will get knock with 28* of advance, drop the area where it occurs by 6* and fade it out to -2* in adjacent cells and still get in almost the same amount in the same areas.

Thanks

[WeathermanShawn]

Have you altered your 'Spark IAT table' B5911?

Those are some high IAT's for WOT.

A lot of people will adjust the B6203 & B6207, Knock Attack Rate and Knock Recovery Rate to lessen the usual amount of spark being pulled.

If it is resonance, I would try to find a different stretch of road or track and see if it is just an exhaust pipe banging around. Sometimes you will register knock on a highway ramp that actually had a decline in it, but never will on a flat stretch.

I never had much luck with the 'try higher octane gas' answer. If it is real hot outside, I just do not run as much timing.

[Aloicious]

Have you altered your 'Spark IAT table' B5911? My tune would pull spark with those IAT's. Those are some high IAT's for WOT. It would be interesting to try it in 40F air and see if you still get some knock.

A lot of people will adjust the B6203 & B6207, Knock Attack Rate and Knock Recovery Rate to lessen the usual amount of spark being pulled. Maybe you have already done that.

If it is resonance, I usually try to find a different stretch of road or track and see if it is just an exhaust pipe banging around. Sometimes I would register knock on a highway ramp that actually had a decline in it, but never did on a flat stretch.

I never had much luck with the 'try higher octane gas' answer. If it is real hot outside, I just do not run as much timing. Higher cc heads, just get hot.

Always a tough one to figure out. Hope you find the answer.

..WeathermanShawn..

I just got my internet working again, I'll try to take a look at those logs and see if I can see anything

I have adjusted the knock recovery rate in my tune, this allows it to still pull the needed timing for KR and safety, but it recovers quicker, rather than dragging out the KR longer than needs be. it'll get you back to normal faster but still won't fix the knock itself. I'd say work on eliminating the knock first, then worry about the recovery rate.

[Aloicious]

okay I looked over your logs, and both the newer tune, as well as the other tune you posted in your other thread. I noticed a few things off the bat, first off your new tune spark map doesn't look like you lowered the spark maps much, in fact your new map looks even more agressive in areas than the old one. secondly, your KR max is only 4* when in PE, this means you're maxing out the PE, meaning the PCM may *need* to retard the timing even more, but it isn't allowed to. try this tune out, I lowered your spark map in the problem areas and smoothed it out a bit, I also raised your KR limit to 15* at any point, this should allow you to see ALL the KR that it needs to retard. I also raised your KR recovery rate so that when you DO get KR, it will return to normal faster. from the looks of your log and tune, its really looking like you DO have spark knock to me. so this should help

so load up this tune and do some more logging, and post up your new logs. don't be surprised if you still have some KR, it SHOULD be less than before, but since you were maxed out on the KR previously, there is a little possibility that you could get more.

[tatasta]

Aloicious,

Thank you for working over the tune. I understand what you have done and it certainly makes sense. I know I am always too concerned about pulling timing, thinking that lowering timing will equal lost performance. I simply don't understand the intricacies of these engines yet. It is a bit confusing looking at dozens of different tunes and trying to find the "silver bullet".

Will an LS1 make max HP/Torque at a setting of 20-24* advance at WOT? Obviously there are endless combinations that require different values but should I get "the more the advance, the better the performance" thought out of my head?

Thanks again and I will load this tune in a few days when I am off of work.

Robert

[Aloicious]

Aloicious,

Thank you for working over the tune. I understand what you have done and it certainly makes sense. I know I am always too concerned about pulling timing, thinking that lowering timing will equal lost performance. I simply don't understand the intricacies of these engines yet. It is a bit confusing looking at dozens of different tunes and trying to find the "silver bullet".

Will an LS1 make max HP/Torque at a setting of 20-24* advance at WOT? Obviously there are endless combinations that require different values but should I get "the more the advance, the better the performance" thought out of my head?

Thanks again and I will load this tune in a few days when I am off of work.

Robert

more timing can be better for performance, to a point, but not when you're getting KR. and higher isn't better when its causing problems. knock is bad, if you're getting knock at 24*, or 12* (and its spark related) you need to lower the timing, period. detonation will destroy performance and engines, much more than reducing the timing a few degrees. Ideally you want to get on a dyno and tune the spark there. that tune I posted is just kinda preliminary, if you run it and find the KR is totally gone, rock on, then you can experiment, try lowering the AFR, and increasing the spark a little bit at a time, doing logs in between, when you see ANY KR, back off the timing a little, until its gone, then an extra ~2* for safety.

[WeathermanShawn]

I make more power at 22-24 degrees of timing at WOT, than 27-28 (Dyno Tested).

A lot depends on your Heads, Cam, CR, etc. I was also doubter for a long time than less timing could produce more power. I have made more power gains just keeping AFR from 12.7-12.9 at WOT with zero ping, or knock (unless it is 100F+).

The 22-24 degrees of Timing was still 2-4 degrees less than my knock threshold.