I see counts, on datalog recording, I playback I see a bunch at X rpm, how do I know how much timing to pull? do I pull a little and drive again? is there a rule of thumb?

 

depends on severity... if the ECM pulls 3* or less, it's something you can work out slowly.

if you see it max out the retard, like 15* or so, then you should move in large steps...

but i have taken it out .35* at a time and gotten to the point of no knock at all within ~10 burns where there used to be 4-5* guaranteed with the right amount of EGR and a locked TCC.

 

yeah for my car, i've seen 2-3 deg pulled, so I just pulled 2 deg and most of it went away. If its pulling 1 deg or less thats usually ok, but you can start taking alittle bit out at a time. Knock sensor's sensitivity can be adjusted alittle with the ESC attack rates and decay rates.

 

is it not "insurance" to leave knock sensor sensitivity at factory settings? why would I artificially, "call and knock not a knock? what benefits? is it not better to work out all the Knocks and call it a day?

Besides I think even "stock" cars will knock given the right situation i.e. bad gas, hot temps, automatic being in the wrong gear,or driver lugging the stick car etc. hence the safeguard of sensor induces spark trimming? correct?

 

The biggest problem with our cars when modded is identifying real knock from false knock. Letting the settings alone may have it pulling timing when it hears noise that is a similar frequency to knock but isn't actually knock. Also, even if it is knock, it will pull way more timing than needed and keep it out for way longer than needed. Best to tune it so you get very little or no knock retard. Yes, you can leave the factory settings but if you have it tuned so that it is getting very little or no knock retard, set it so the max knock retard is like 3 or 4 degrees so that if it gets bad gas it will pull some timing, but it won't pull 15 degrees due to hearing a touch of false knock from a header or roller rocker or something.

 

Like said, you can have false readings from other things. i had them with header/ypipe hitting the frame of the car. I get them when doing a burnout. My turbo car will sometimes pull 7-9 deg during a burnout for some unknown reason but during my pulls thru the same boost range and rpm range, I get nothing.

You can adjust how much timing is pulled. Stock settings are like 15 deg which is ALOT. Rarely does it ever pull that much but it can and that can really limit power. I just set mine to about 4-5 deg. I tune it slowly til I see 1-2 deg of spark retard and then i back off a bit. Its better to be conservative with timing until you can be 100% sure that a knock count/spark retard is false. If you can prove its false, then you can play with the max amount pulled and correct the mistake.

But being conservative and tuning all the knock counts out is the best way to do it. AFR's dont need alot of timing advance anyway, so you should still make power with somewhat conservative timing.

 

Question on KC's and subsequent retard. If I disconnect 12V reseting BLM to 128 I presume it also erases any knock SA reduction that occurred prior. Is that correct? If so is my SA permanently effectively changed as the ECU retains that K retard?. Or on key off does ECU erase prior KC's and use the SA table fresh for next restart?

My personal experience is that my attempt to eliminate KC's, I reburned bins with less SA in that cell. To no avail they always came back. That is mechanical so I reduced the max SA retard to 2 degs and called it a day.

I will take a look at KC attack rate and I believe it might be beneficial if I reduce it and increase the decay rates.

 

For me, spark retard that occurred at certain spots went away when i pulled some timing out. Usually if i saw say 2 deg being pulled, I'd reduce my spark advance 2 deg in that spot and I'd never see it again.

If it keeps coming back and doesnt respond to timing changes, it could be a false knock/false retard. Hard to say.

If its just overly sensitive, reducing the attack rate can help alittle. Same with increasing decay rate to allow full timing back in once that spot is passed.

On code $59 I have read that once you pick up a hint of detonation/knock, it will pull timing and not put that timing back in through out the WOT run. I've seen this on my setup where I'd have a hint of knock at lower rpm during launching, and see 4 deg pulled throughout the rpm band with no response to timing changes that I've tried.

I eventually found the spot that was causing it and was able to eliminate the retard.

I dont think 6E/8D codes have any of those problems. From what I remember with my L98 and 383 HSR, i'd pick up spots of spark retard, and as rpms pulled, it would decay out. By limiting the attack rates and increasing decay rates, timing was retained. I didnt get to play with the timing as much as I would have liked. I set it and forget it on that setup because I was happy with how it drove with about 35 deg timing basically locked out for all part throttle ranges. That spark table mimic'd a carb car basically. Idle was one thing and by certain rpm it hit max timing. Only idle and WOT I played with alittle bit back and forth and that didnt take too long. It was happy with 28 at idle and 34 at peak torque all the way to redline.

 

Heres some useless info. I only get knock counts when the back tires are spinning. If it hooks, no knocks. Slick, are you getting knock counts all the the time, or just sometimes ?

 

enough time and info has passed this thread for me to work out most of the knocks, as far as false knock I, started the motor from a stall on the intersection one time and saw around 39?

crazy... anyhow, have not "hooked up" the clutter of gear as of late in the car, as archaic as it may seem " I have not heard anything lately" and I do punch it to "test" it on some open stretches, I even backed off on the max retard a bit, as per the help given here, and no ill affects yet.

I am not tuning with a vengeance per se, just popping a chip in every time I have to run an errand or something, and let my wideband,"best-friend" lately, and my butt meter and my listening and watching do some caveman dataloging.

so far fun and effective, I get a better, faster, more fuel efficient, tamer, car to drive... what a hobby....only if other things went as smooth, if you can call this smooth...

so far, cruises at 14.8, open loop, then with gentle acceleration drops to 16, a little more gas and it goes back to stoich, this is just driving with the flow of normal street traffic, you know topping out at 40mph or so.

should I do some enriching on the MAF at .55 volts? or I pretty much zero'd the AFR coolant temp at "operation temps" left a just little enhancement before 180 degrees, to help it warm from the "cold soak".

I have thinkin AFR VS. LV8 I could bump that up for the load area I am going lean on mild acel, or????? thoughts?

 

If you got some lean spots in normal driving you can do one of 2 things...

Change the MAF table values or maybe the AFR % change vs LV8 for open loop. Either one is fine. I liked MAF tables.

Sounds like you are playing with table 2 and maybe 3 for normal driving. Try to note what the MAF grams per second value is at those lean spots. Then go into the table and find where that grams/second value is. Add abit more to the two cells that you are operating between to richen it up abit. This is abit harder to do because you need to quickly watch the datalog and your wideband gauge. its handy to try and mount the gauge near the screen if possible

Tunerpro doesnt datalog MAF volts so you can just simply note those values and change the table. Thats the way it should be but doesnt work that way. You need to note what the air fuel is for a given grams/sec flow. Make sense??



Or just note the LV8 in which your abit lean and go into the open loop AFR vs LV8 table and add few more percent in that spot and see what happens. Thats a global change so you can fine tune cruise air fuel from there.


If under mild throttle increase, its going lean and seems to hesitate or just feel weaker than you'd expect, it may need more acceleration enrichment. There is an AE enrichment table vs change in LV8. Say you go from 64 LV8 and quickly depress throttle so now the LV8 is 96. thats a change of 32. The table has delta LV8 values of 0, 64, 128, 192 and 256. So you'd want to increase the 0 and 64 cells slightly to improve the change of 32. AE has other settings like TPS % I believe to enable it, so it may or may not be coming on. More than likely on smaller changes like that the MAF is doing most of the work. AE is something to check just in case. Its really helpful on WOT mashes from off idle or light cruise where change in LV8 is large and rapid.