spark timing and kr issues

[LETZRIDE]

I am stumped on this one I can't seem to get more than 21* spark out of my camaro without getting knock- I don't get it all the time, but I would say about 75% of the time at WOT only with just 21* spark being commanded and I can't figure out why- to me I should be able to put 26-28* into this thing and feel I am leaving power on the table for sure.

2nd part to this is- I notice when I shift, I drop to like 12* spark and it takes a whole second to come back up to 18* and climb again...there has to be a way to make this faster no? that is a lot of hp being dropped off on a shift and spark recovery- what tables would cause this issue?

As far as the kr is concerned, my only best guess is that my steering shaft rubs my headers and MAYBE under WOT conditions this causes KR? But at the same time I doubt it...I have an aeroforce gauge that monitors KR and my shaft rubs on all the onramps/offramps/turns of the steering wheel and I never see KR flashed up on my gauge when that occurs- only ever at WOT...and my gauge is set to flash at me if I get so much as 0.1KR come up.

The car is my 2002 LS1 Camaro

Mods: 1 7/8 LT headers, no cats, corsa exhaust, Lid, 3.73 gears, 3600 stall, Ford 8.8 rear end, and then a bunch of suspension mods.

My Maf is tuned 99% and I have disabled it to dial in my VE tables which are at about 95% completion right now. WOT I am commanding 12.84 AFR until I get up to close to 6000rpm and then it goes down to 12.5s

I am attaching 2 scans and my config files along with my current tune...the other thing that is messing with me is the shift patterns on this car...I was shifting 1-2 at 6190 when I was asking for 6000rpm and sometimes bouncing off the rev limiter...I lowered the shift rpm to 5925 to try and compensate and now I shift at 5600 rpm when my mph is reached... doesnt make sense to me

Camaro SD tuning Sept 2016.hpt
Mikes configuration camaro.Channels.xml
mikes graph layout.Graphs.xml
sept 13 run 3.hpl
sept 13 run 4.hpl

[5FDP]

Both the MAF curve and VE table has some pretty wild spikes in them, they will need to be alot smoother for sure like the factory curves.

I didn't get a chance to load the layouts but when tuning one or the other, remove whatever channels you aren't using. Like when tuning SD, remove MAF channels so it doesn't skew data. I assume you are using an AFR error with the wideband you have.

[LETZRIDE]

I do have the Maf channels removed- P0101, 02, 03 all set to MIL on first fault and maf unplugged.

I know they have some spikes, but I give the car what she likes, they'll smooth out a touch more within the next few days as I finish massaging them out, but once I get within about 1% in all my VE and MAF cells with AFR error, I let that sit as is.

But only being able to have 21* timing when some of the factory ls1 Camaros have 25-26* in the tune repository boggles my mind...

[LETZRIDE]

I do have the Maf channels removed- P0101, 02, 03 all set to MIL on first fault and maf unplugged.

I know they have some spikes, but I give the car what she likes, they'll smooth out a touch more within the next few days as I finish massaging them out, but once I get within about 1% in all my VE and MAF cells with AFR error, I let that sit as is.

But only being able to have 21* timing when some of the factory ls1 Camaros have 25-26* in the tune repository boggles my mind...

Bump- anyone have any ideas?

[dermotw]

Hi,

Well, as 5FDP said, you need to smooth the maf and ve tables for sure, sharp changes increase chances of knock... also, (just my uninformed opinion) your spark table is not typical, try comparing to a few others, usually they are very steep initially, then drop a bit in the high torque area, then climb (a little) as the rpm climbs. BTW I also saw that your retard compared to IAT is much more than mine (and my IATs can be very high).

Err BTW is your car a V6 like your sig says? If so, you are really asking the wrong people! -Repost it...

[LETZRIDE]

Hi,

Well, as 5FDP said, you need to smooth the maf and ve tables for sure, sharp changes increase chances of knock... also, (just my uninformed opinion) your spark table is not typical, try comparing to a few others, usually they are very steep initially, then drop a bit in the high torque area, then climb (a little) as the rpm climbs. BTW I also saw that your retard compared to IAT is much more than mine (and my IATs can be very high).

Err BTW is your car a V6 like your sig says? If so, you are really asking the wrong people! -Repost it...

not a v6- that is the old car I had- my current car I am tuning is a 2002 LS1 Camaro.

my spark tables and retard tables I took from a holden monaro file as I activated Lean Cruise on my car and have been slowly building the spark tables from there. How would the sharp edges in the MAF and VE tables effect anything if they are commanding within 3% of the fueling I am asking?

[dermotw]

Well, the tables are just a guide for the ECU, in a way. the ECU is constantly recalculating and of course it is "between" the points on the tables most of the time, in fact. It's also trying to predict values, same for the spark, so sharp changes in one area are likely to cause sharp changes in another, or overshoot/undershoot of values, it doesn't just step between the values in the tables. The <precise> things it does to decide what values to use are actually unknown to us, of course, at least as far as I know, but I know it's complex! One of the important things I believe is whether or not the ECU thinks the MAF is in "steady state", which is one reason why the MAF curves should be smooth...