Burst knock and KR
06-14-2006, 02:49 PM
#21
TECH Addict
Originally Posted by dewmanshu
The way I read it, and this is as lamen as I see it, if the ecm sees (i imgaine from some complicated calculation) that your delta g/cyl is out of its range by what you specify in this table (0 g/cyl to 8 g/cyl) it will pull...er apply knock retard as per the value you have in the Burst KR vs rpm. I guess what its saying (pure speculation) if at any given rpm you (or your truck) can produce more air than what is specified while still in that advance table/cell, it will apply the kr(as per your settings in these tables). I have also read that once the requirements are met to cause burst kr, it is a timed event...all or nothing deal, no attack rate or decay rate. Once started, it exists for the entire duration of whatever parameters the genius' have in mind. It's also supposedly only measured at throtle blade opening. So if you are already on the gas and haven't encountered it, you won't. But if the TPSis 0% and you nail it...the pcm is looking to see if those parameters are met to enact the prescribed bkr.
Whew, take a breath now. LOL I just made all of that up, sounds pretty good eh? LOL
Oh yeh, your first question, Shhh...I zero'ed mine out a month or 2 ago.Hush hush.
Whew, take a breath now. LOL I just made all of that up, sounds pretty good eh? LOL
Oh yeh, your first question, Shhh...I zero'ed mine out a month or 2 ago.Hush hush.
06-14-2006, 03:16 PM
#22
TECH Enthusiast
Thread Starter
Join Date: Dec 2003
Location: Western WA
Posts: 572
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by dewmanshu
oooh if you look at GMC DUDE's tune, he has the extra table for engine run time. Mine doesn't.
GMC DUDE I don't see anywhere in your tables where it would pull 15*, even with the multipliers. Do you have a scan of this "timing pull" ?
GMC DUDE I don't see anywhere in your tables where it would pull 15*, even with the multipliers. Do you have a scan of this "timing pull" ?
Note that there is no actual KR being triggered (that PID does work btw), so it's not seeing any actual knock, just speculating, I guess.
06-14-2006, 04:41 PM
#23
Originally Posted by GMC_DUDE
Yes, attached is a run I did Sunday, you can see in the run-up near the beginning that it goes from about 18ish to 1.5 After TDC. Note that there is no actual KR being triggered (that PID does work btw), so it's not seeing any actual knock, just speculating, I guess.
Note that there is no actual KR being triggered (that PID does work btw), so it's not seeing any actual knock, just speculating, I guess.In your tune look at your spark table (high) at .68 g/cyl to .88 g/cyl in the 800rpm column. Then look at the same areas in your low octane spark table. Now look at your scan (more importantly, the histogram), your pcm is just doing as it is told. As you move your mouse over the trouble spot in the "graph" watch the "histogram #1/spark". It's close enough to commanded spark. Don't forget you need to factor in that whole "when does it go to the next cell" thing.
So if you are two wheel drive, I shall refer you to one of the timing on launch threads to see if you are a candidate for negative timing on launch, if you are 4wd...just add some timing in the areas you like to see more.
Stock Radix tune? BTW off topic, sorta, on your pe tab...goto the bottom and chage that "rate" to "4".
06-14-2006, 09:26 PM
#25
How do I change this text
iTrader: (26)
Join Date: Jan 2005
Location: Behind the TIG welder
Posts: 7,294
Likes: 0
Received 2 Likes
on
2 Posts
I'd raise the table, like dewmanshu said. Plus it looks a bit fat above 4600.
What have you done to the trans to hold up with that Radix and no Torque managment?
What have you done to the trans to hold up with that Radix and no Torque managment?
06-15-2006, 03:10 AM
#26
TECH Enthusiast
Thread Starter
Join Date: Dec 2003
Location: Western WA
Posts: 572
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the help, everyone. I had looked at the spark tables, but my brain was thinking that since I brake stall at about 1600 rpm, that I should look at the timing there. Somehow I didn't think to look at the actual rpm. Checking some other logs confirms what Dewmanshu said. Boy do I feel stupid right now. 
Anyway I will increase the enrichment rate like you said, and will play with the timing at the low end. Yes this is a (more or less) stock Radix tune, the only changes I've made so far was to rip out all the TM, and to tweak the idle speed and airflow settings a bit to improve drivability. The truck is 4WD, so tire spin is not really a problem.
The reason I started really digging into this was because my first time at the track resulted in a wretched 14.8@90, and I know the truck can do better than that, heck, it just "feels" faster than that.
So I guess my next question is: how much timing should I add as a starting point?
Again thanks for the help. I really appreciate it.
Anyway I will increase the enrichment rate like you said, and will play with the timing at the low end. Yes this is a (more or less) stock Radix tune, the only changes I've made so far was to rip out all the TM, and to tweak the idle speed and airflow settings a bit to improve drivability. The truck is 4WD, so tire spin is not really a problem.
The reason I started really digging into this was because my first time at the track resulted in a wretched 14.8@90, and I know the truck can do better than that, heck, it just "feels" faster than that.So I guess my next question is: how much timing should I add as a starting point?
Again thanks for the help. I really appreciate it.
06-15-2006, 04:32 AM
#27
I honestly looked at a bunch of different FI .bins when I first starting doing it, not just copying but trying to understand any similarities in their timing tables. Divide your spark table up into sections...Part throttle, Hauling ***, Launch, and WOT. Work on each section separately, but blending them all together. Add 2 degrees to your launch section add work from there. For example when I first had my Nelson tune the area you are in on mine was like 9*. Now in .68 to .88 on mine it's like 13*. With my stall though I never see that, I always see over in the 1800 column....17*. Just be careful add pay attention to kr and what your engine will like. Remember, she's heavy.
As Wilde asks, you may want to throw a servo or shift kit in the 60e if you haven't already.
As Wilde asks, you may want to throw a servo or shift kit in the 60e if you haven't already.
06-15-2006, 10:11 AM
#28
How do I change this text
iTrader: (26)
Join Date: Jan 2005
Location: Behind the TIG welder
Posts: 7,294
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by GMC_DUDE
So I guess my next question is: how much timing should I add as a starting point?
Again thanks for the help. I really appreciate it.
I have used the on/off controls in the scan program to add spark while driving. I'm not sure if this is the safe, but it is fast.
Thread
Thread Starter
Forum
Replies
Last Post
