Ignition retarding

[ScoobyDuck]

Hi all,

Any advice on whats going on with silly (1/2 throttle, low-ish boost ) ignition retards? (cel light - as thats set to 4 degrees).
Looks like its occuring on lift off but also it has already occured (not captured unfortunatly) and still retarding Cyl4 before the larger spike.
Am i just too high on gain ?

thanks
Steve

[stevieturbo]

Screenshot tells little.

Cannot see logging rate, cannot see base timing, cannot see whether knock control is doing much other than that on 4 etc etc It would seem the threshold has been clipped for this retard to happen, but we cannot see where your thresholds are set.

As for how any timing appears ( in seconds, not ign timing ), again logging rate can vastly affect what you see on screen when trying to relate things together.

In short, not enough info.

[ScoobyDuck]

Ok thanks stevie. Will post the log when back at the pc. IIRC the knock is 50hz retard degrees is 10.
Should have said it's not retarding on others but similar noise present on knock cylinders.
It's only got the basic knock in the ecu.

Steve

[ScoobyDuck]

log file uploaded

logging is set to what I call my everyday one. this wasnt done specifically for this even.

Steve

[ScoobyDuck]

Same file, screen shot for explaining what i mean @17:52:48
Dropping ~10degrees for a reason i cant see ! maybe this is the logging not fast enough to catch indiviual cylinder changes? Could be cyl 4 with ~6 knock retard and -2 cyl correction ? no wonder its not happy - hardly smoth

Whats the general idea of retarding each cylinder -2 degrees (cyl4), where others are 0 ? Just more det prone?

thanks
Steve

[stevieturbo]

Logging rate for "knock" seems to be 1000Hz, very good for listening.

But most of the retard that is in place, has been in place long before that particular log. But in general all cylinders seem very quiet ( yes gain and other settings can affect that though, but I doubt there's a problem ) . Where the additional retard is occurring, and boost/rpm etc...it's probably nothing at all and just the base knock threshold tables need lifted a little on that cylinder.

Not sure what parameters are available to the restoration of timing with the basic after things have gone quiet again though. I only ever used the basic years ago on a friends and it did exhibit the same behaviour, but we upgraded to the full knock to give full control over the removal and then restoration of timing.

But some engines through design, some might feel some cylinders want a little more or less fuel, or a little more or less timing. That's up to whoever is tuning it and how things sound/feel at the time etc and based on the engine/build.

Would you actually feel it pulling 5, 6 deg etc on a single cylinder ? probably not.

it is showing final ign timing much lower than base in a few other random areas, but it isnt logging anything that would identify why it is doing that that I can see.

[ScoobyDuck]

Stevie

i've checked the scfg that i put on the car and its 50hz

yes the 5degrees was before this but for some reason there was no log for that, even though its set for 2500rpm + 25% throttle. It cant be happening before that!?
I've looked at what else could be affecting the ign regtarding and almost all the maps are flat 0 at the values (BAP =103 = -0.66degrees : ACT1 = 29.2->28.6 = both 0 )
There is no Fuel pressure ,gear adder, load adder tables with anything in.

Basic knock you cannot do anything with how much to take or give back, it just does it. Settings are gain, throttle % enable (40%) ,engine speed (2000) & knockbase, which i've never really undersood to be anything but a 'level' ?)

Code: Select all

7.20215	14.0381	21.1182	27.6855	34.4238	41.3086	54.5654	68.0908	81.8848	95.0195	95.0195
7.49512	15.4297	22.6807	30.1514	37.4268	44.9951	59.8145	74.5605	86.4014	95.0195	95.0195
7.10449	14.1357	21.1182	27.8809	34.6191	41.4063	54.8584	68.3838	81.8848	95.0195	95.0195
6.93359	14.3799	22.0459	29.5898	37.0117	44.3359	58.8379	72.998	86.4014	95.0195	95.0195

The point i might have been focusing (incorredtly?) was the swing of ignition . This may not be the case as it may be cylinder 4 thats low every cycle and so more constant per cylinder. I'll have to up the logging rate for Ign (only 10hz currently for IgnFinalPri1)

Anything else you can suggest I log to get a better picture of this?

thanks for the input
Steve

[stevieturbo]

Knockbase is the threshold level, it's a lookup table, little different to a fuel table, ign table etc etc.

SCfg may not always allow you to log the knock threshold at any given time with the base knock config, but on the other configs with full control it is there and you can load this into the basic ecu. But you need to do it from file each time, rather than pulling the config amending then re-sending it back to the ecu.
No idea why that is. Obviously it's not essential to log this, but when you have both on the same graph it just makes visualising it all much easier.

So if you lifted the values in the first cell or 2 of cyl4 on knock base ( event level detection ), that is lifting the trigger threshold for control to do anything around the noise levels the ecu is recording ( ie 7.3 in that case it would seem ) ( ie, so first cell is 5, second 10...your lookup threshold value is in the middle of these. )

And your knock levels are being recorded at 1000Hz according to the log file. Base/Final at 10Hz. Likewise corrections at 10Hz.

Just lift the threshold up, I dont see a problem. If in any doubt, manually listen with det cans etc.

[ScoobyDuck]

Stevie

ok thanks. Will have a look and see what the values are on the car. I cant see how you can see what the logging frequency is in the log. Am i just being blind ?
I have a feeling the old cfg was set to knock even logging @ 1khz, so may be that is still there.
I'll also add the knockbase to the logging fresh.

I will raise those first 2 cells. As its so quiet (although that depends on gain i guess (curerntly set to 1.231))

I wonder if Syvecs are still doing the 'upgrade' (I thought it was free at one point? or was i asleep again ).

thanks
Steve

[ScoobyDuck]

yep, knockbase isnt there which is odd becasue it IS there in some older logs! (current ver = 1.74.2)