basics of tuning delco non $12p

[krusty]

Good stuff Ken. Just remember Ken, lean cruise at 18:1 is viable and completely doable on a cammed and cooled L67. Just have to make sure it's tuned to do so.

Once you get a handle on the RT stuff, a few logging runs with the WB enabled will sort it out. I'd err on the rich side of things on the road and then scale it back to where commanded AFR = actual AFR.

Depending on the set up 18:1AFR may not be achievable so just keep an eye on your knock retard while this is all going on and that will be your warning of the commanded fuel trims being too lean if at all. Doing all of this on a cool night and on a slight up hill gradient is a good way to make it safe. Cold air means more O2 in the intake charge which would reduce lean out if you tune for this worst/ best case scenario.

[sprattzvx]

hey people got a few more questions.

the table open loop vs a/f ratio vs mgc only diplays upto 4800rpm. so, even though maynot be the best way to do it, i guess a way i can add fuel up high at wot is by use of pe enrich multiplier versus rpm i think. ive increased the multiplier value in small increments at each rpm point upto 6400 rpm. something like this.

1.203 4000
1.305 4800
1.406 5600
1.500 6400

the reason for this is ive adjusted my shift points at wot to 5900 and fuel cut to 6000(i may have to go to 6100 as it hits fuel cut before shift finishes), to make better use of the cam. so now im getting knock over 5600 rpm when o2s drop steeply. if im understanding this correctly, the manifold gps is maxed at around 5000 rpm, so its fueling for 245 gps of air from 5000 onwards, and the leanout becomes too much at 5600 then it knocks.
so basically i wanna fatten up the fuel so its real rich at 5000, and have it lean out to a good ratio by fuel cut, just as a bandaid fix until i suss out the maf tables.
hope this makes sense..

flat.xdl

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here is a very short log of what is happening.
thanks.

[krusty]

Ken, you need to use Injector rate constant Vs mg/cyl Vs rpm in AIR FUEL RATIO settings tables mate. I strongly suggest that you put the rev limit back to where it was until you get a better handle on stuff. I like you initiative but it's too easy to chip a piston up in those ranges.

My theory on rev limits in an auto isn't to stretch out the power as many rpm as possible because the more rpm you go to the more inefficiencies come forth imo. What's important is to hit the next gear right before the meat o the usable torque.

If you feel that the car really is making power when extending the shifts at least reduce timing to start with and check out the AFRs carefully. Then play with adding timing by maybe 2 degree incrments in the high octain tables. Also be careful when reducing timing that the value in the high octain timing table doen't actually go below the value for the same rpm vs mg/cyl load point. There must always be a threshold between the high octain and low octain tables otherwise the pcm will just start chopping timing and you won't really have a reference as to why.

On the right track though. Good stuff

[Holden202T]

if your hitting the rev limiter before shifts then you need to adjust the shift tables to shift at lower km's

[sprattzvx]

Ken, you need to use Injector rate constant Vs mg/cyl Vs rpm in AIR FUEL RATIO settings tables mate. I strongly suggest that you put the rev limit back to where it was until you get a better handle on stuff. I like you initiative but it's too easy to chip a piston up in those ranges.

My theory on rev limits in an auto isn't to stretch out the power as many rpm as possible because the more rpm you go to the more inefficiencies come forth imo. What's important is to hit the next gear right before the meat o the usable torque.

If you feel that the car really is making power when extending the shifts at least reduce timing to start with and check out the AFRs carefully. Then play with adding timing by maybe 2 degree incrments in the high octain tables. Also be careful when reducing timing that the value in the high octain timing table doen't actually go below the value for the same rpm vs mg/cyl load point. There must always be a threshold between the high octain and low octain tables otherwise the pcm will just start chopping timing and you won't really have a reference as to why.

On the right track though. Good stuff

Ok im maybe getting ahead of myself abit, i think ill take your advice and chill abit on the original rev limit, before i end up posting an engine death thread.... Ive been adding small increments of timing, seeing around 15d through the midrange tapering of to around 10 by peak revs, its definitely liking the timing. Im only adjusting the 800-850 mgc area.
Ive also increased line pressures at wot and its hitting the next gear pretty hard, which is kinda why im going for the higher shift points, if i get it to rev out cleanly to 5800 which its eager to do, then like you said andrew i can get it to dump hard into the next gear right in the sweet spot . Not sure how adaptive shift works but it maybe working against me here.
202 im tryin to strike a balance with the shift vs fuel cut. Cant help but feel im missing some info from my logs...is there a way to increase the sample rate/resolution when logging in tp?
Sometimes the desired snap shot seems to be between frames, ie fuel cut at 5900, you know you hit it, but last known rpm before backin off in log is 5700.
Thanks guys.

[krusty]

Like 202 said, maybe command gear shift 100rpm earlier. I'd also suggest leaving trans line pressures where they are as they've already had a small increase in the base tune as have the commanded shift rpm.

If the shift command rpm decrease doesn't work another 100rpm earlier again wouldn't be the end of the world. This will also give you an idea of your shift extension, the difference between commanded shift rpm and actual

[sprattzvx]

ok rev limit and shift points are back to original settings. also pe enrinch vs rpm and advance is back as was. ive had a look at a/f vs mgc vs rpm, and considering the difference between the minimum injector rate, and the maximum is around 0.150, this setting is very sensitive and should be only slightly adjusted. The injector rate constant is measurement of opening time in milliseconds isnt it?
anyhow, ive increased the rate from 1.023 to 1.031 in the 600 to 700 mgc from 5200rpm up to 6400, and from 1.031 to 1.039 as it passes into 800 to 850 mgc range. the rest of the fueling is sweet so no need to touch. ill log this tonight and see how it effects the top end a/f. i really need to integrate the wide band to tp, but not worth the risk, if the wideband goes then safe tune goes back in and the interesting stuff stops, so ill just have to go by 02 volt trends up high, all happens to fast to eyeball the w/b.
haha anyway enough with the babble.

[krusty]

The wideband should have it's own stand alone logging with an rpm pick up that you can run from the cam or crank sensor

[Holden202T]

commanding gear shifts is via kph not rpm so just try decrease the kph 1 at a time and see if it makes a difference. you should only need to lower it 1-3 kph to sort the issue.

[sprattzvx]

captains log stardate 13.9.2011 made the following observations from the bridge today during rostered r&r whilst in orbit around orions belt in the Arcadian system opposite the nebulous black whole at approx 21:29 earth time::
ok some strange shit going on, strange to a noob anyways. took a log after adjusting the injectors constants in mc/rpm.
when i drove earlier on after the changes it was still warm, and all seemed peachy o2`s seemed safe as up high around 960 which is rich as i think, wide band was showing good a/f,the commanded a/f in tp was down to 11.2 which ive never seen on this tune before, must be tp recalculating the commanded a/f partly using the inj rate con mgc/rpm table along with the other linked tables. and it smelled a little rich which was great as i could just trim the constants back a bit to get things just right.
but just when for another roost for a log, and now i spied the w/b just before shift, and its shot up to over 11.5. commanded is back to 11.3 also.
when i looked at the log, 02`s where now tapering off again into the 800`s, no knock at all, but not a good place to be wot max revs i'm sure. only thing thats changed is ambient air temp and its not that much.
anyway looking at the injector pulse time, i noticed the pulse increasing gradually with air flow and rpm until around 4500 revs when the pulse time is dropping off in corresponding amounts to the 02 voltages. whats with that, i would assume the pulse time would remain constant after the 245gs ceiling was reached fueling for this volume of air for the rest of the rpm range. pulse time doesn't just go backwards of its own accord does it...it either keeps increasing or maxes out steady until airflow decreases and it drops off......unless theres something commanding the lower pulse time for some whacked reason.
why the fuc%k is injector pulse time dropping? this is the source of my problem? its maxing at around 970 ms then dropping off?
but seriously, any ideas?

00 (2).xdl

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you can see exactly whats happening right at the end of this, just before the data connection drops...