2MCHPWR

iTrader: (10)

awesome. thanks so much! i made these 3 settings and will try to log tonight. Gonna hit a mustang dyno friday afternoon.

-copied high octane to low octane,
-smooth function to MAF table,
-changed MAF Airmass Filter to 0.09144 (from 0.1016)

JakeFusion

iTrader: (7)

I see COW in the line of your tune... is this a ChuckCOW special?

Darth_V8r

iTrader: (4)

dude, that's funny, and yet, how many motors HAS he blown?

2MCHPWR

iTrader: (10)

yeah its from chuck.
so the pulls tonight were the best yet. barely any KR. can you look at this log?

smoother MAF graph like you predicted. Is a cammed car ever going to have a totally smooth maf curve? does the jagged maf curve impact the KR?

its a full on 3rd gear pass on the highway and then another in 4th to 125mph.
questions:
the 3rd gear pull gets .4 KR almost as soon as i mash the pedal. why? only 2800 rpm. but quickly goes away and doesn't come back for the whole pull. what makes KR happen when you mash it?

in the 4th gear section: 1.6 KR at 2800 rpm again? is 2800 a magic area for KR or something? it goes away but comes back at 3800 RPM but only .5 KR this time. quickly goes away and doesn't come back for the full pull to 125 mph. I would have thought if there was an issue that there would be KR at the top end which is under more load.

timing is extreme and a/f looks solid.
thoughts?

outkast6991

iTrader: (34)

Is it burst knock? That would be at heavy throttle transitions

Darth_V8r

iTrader: (4)

I can't see the log until I get home on Friday. Glad to hear you're making progress.

The MAF line won't be completely butter smooth, but shouldn't jump too much. The wide swings in MAF readings will cause momentary under fueling, which can easily cause knocking.

You're actually most prone to knocking near peak torque. Highest cylinder pressures.

Burst knock is a great thought. Also, now that you're not getting KR under all conditions, you might just need to pull 1 degree out at 2800. If you pull 1 degree and get the same KR, I would strongly lean towards burst knock

You could also put the MAF filter to .0898 to match the stock Z06 setting and smooth out the MAF even further.

statesman

It can, but only if everything else in the tune is right.

2MCHPWR

iTrader: (10)

so i can lower timing at 2800 to see if that helps.
but also since car is a 98, this is the only burst setting I see. Should I experiment with lowering it and/or zeroing it out?

outkast6991

iTrader: (34)

I'd zero out the burst knock and see if the problem changes. Burst knock is simply timing being pulled in anticipation of a situation that COULD result in a knock condition.

ddnspider

iTrader: (26)

burst knock is useless on a highly modified car, zero it out.

2MCHPWR

iTrader: (10)

awesome. thanks again. stuck at work but will change it and log it tonight.

2MCHPWR

iTrader: (10)

is this true? i found it in old thread. If its true, then what i'm seeing isn't due to burst knock because there is KR. I think what it is saying below is that burst KR won't affect KR but instead will just lower timing. truth?

is there a burst PID in hptuners 3? i don't see it.

joecar

There is no BKR pid that I could find...

2MCHPWR

iTrader: (10)

i couldn't find it either.

I zero'd out burst knock but i don't think that affected anything because...


first WOT burst was in 4th and got .8 right before 100%tps but went away.
Look at the attachment with the extra data on right side. it's right when PE kicks in and the PCM is calling for 12.7 but actual is 14.4! So seems like that is why i got the KR right before WOT. what can richen that mixture up during that transition to the PE table?




Then a 3rd gear hit, 1.3 KR at 3700 rpm, .96g airmass, timing shown is 20.0. But took it to 5100 RPM with zero KR and 22.5 timing before I let out of it.
But AF is mid 12's the before and after the KR so different situation than the 4th gear burst before.


so i'm gonna drop the timing by 1 degree from like 2200 to 4000, and by .5 degree from 4000 to 4800 and log again.

thoughts?

joecar

Are the PE Enable Delays zeroed...?

2MCHPWR

iTrader: (10)

this?

PE delay 1500 RPM so shouldn't impact what i'm seeing, right?

Darth_V8r

iTrader: (4)

I hesitated posting this, but I guess I'll ask it and learn something.

The point of VE at lower rpms is for that throttle transition, so when you open the throttle, there is a secondary calculation to account for the air going into the cylinder, but the delayed reading at the MAF. I know there's more than that, but that's the background thoughts for the question below:

So, could the MAF only nature of the tune be causing under-fueling during throttle transition, leading to KR?

JakeFusion

iTrader: (7)

The VE is used for throttle transitions below 4000. That's true.

However, I've run a 100mm MAF only for a while and you can't tell once it's dialed in. If anything, the MAF is more accurate at WOT than the VE table since it's reading actual molecules of air. But it you're part-throttling it, there may be a delay in PE kicking in. But look at your tune, anytime WOT is done with the MAF or SD, there's a momentary lean-out until fueling catches up. That's part of the fuel transient tuning.

One other thing to remember is that cylinder temps/pressure rise pretty significantly if the OP is rowing through the gears before 4th gear causes a problem. This makes the car more susceptible to pinging, especially under real-world load conditions you may not see on a DynoJet.

Darth_V8r

iTrader: (4)

I don't disagree about the MAF being more accurate at wot. I guess I was wondering if the VE would predict higher air during a 2800 rpm throttle transition vs the MAF and fuel accordingly. Seems like just getting the KS sensitivity and filter settings has helped.

2MCHPWR

iTrader: (10)

made some progress.
lowered timing by 1 degree between 2k and 4k RPMS.
Lowered timing by .5 degree between 4000 adn 4800 RPMs.
Didn't get any KR during WOT but again got KR during the upshift from 3rd to 4th. 3rd gear pull was great all the way to 6500, then i let go of gas and upshifted. at about 9% TPS, 35.1 degrees advance, KR started at 0.2.
It maxed at at 59% TPS, 18.5 advance and KR at 3.9 @ 4950 RPMs.
by the time i was at 100% TPS, KR went down to 1.4 @ 5038 RPMs.
It was completely gone @ 5272 RPms, 23 degrees timing.

ANy more ideas why this is happening during the shift?
i don't know why but the channels box isn't showing the same data as the graph; graph seems more accurate.
Is the timing during ramp up too high? See that it is 35.1 degrees advance when KR starts .

Log and image attached. Thanks!