Ran The Russk K IDLE but results dont make sense

[JamesLinder]

When you are running short on idle air it is not unusual to see the RPM dip when shifting into reverse. As long as your motor
does not die or struggle to keep from dying then you should be okay. On a cammed motor, you have to have your idle air dialed
in nearly perfectly to avoid RPM increases and decreases when shifting from gear to park, shifting into reverse from forward gear,
etc. More important is the car should not hesitate or drop RPM when you come to a sudden stop! In this situation you still have
some tuning to do.

The adaptive idle settings under the idle-rpm tabs on my tune work quite well for my 230 duration camshaft in my stroker motor.
If stock settings are not working for you when your vehicle is warmed up and you have airflow dialed in, then try the settings
from my file. This is the PID controller you hear about that fine-tunes idle after spark control does its thing first.

[JamesLinder]

oh, take a look at the under-speed timing table values under the spark, advance tabs (bottom left). These are
necessary instead of what GM used when you have cammed motor using this version of their PCM. GM's settings
for a stock motor will not catch rapid RPM drops that can occur with a performance camshaft at idle and when
coming to a sudden stop.

[02pewterz28]

Thanks James, I did an idle log and some light driving and got the maf error values in the histogram. I then loaded them into the vcm and came up with the log below. The thing is when i logged the maf again here I still had error values, they werent at 0 but the trims do look better. Should I attempt to get the maf-ft histogram to 0?

I also lowered got the counts into the mid 20's again and tried to start the car with Russ' tune....No dice no matter what I did it still wouldnt start unless i opened up the set screw then the counts were between 5-10. If I decide to keep the nw would i have to go back and retune the maf and all this again?

Also Russ did the tune effect anything at wot performance wise? Or was it mostly driveability?

maf log 2.hpl

[Russ K]

Ok, you need to get your LTFT's slightly negative (you're 5% positive) and leave the IAC to 5-10. Then after the fuel trims are in line, do a cold start idle scan & post the scan log. Then I can see what tables need changing.

I didn't touch your fueling tables, but I did set up your main spark tables.

Russ Kemp

[02pewterz28]

Ok, you need to get your LTFT's slightly negative (you're 5% positive) and leave the IAC to 5-10. Then after the fuel trims are in line, do a cold start idle scan & post the scan log. Then I can see what tables need changing.

I didn't touch your fueling tables, but I did set up your main spark tables.

Russ Kemp

Ok cool will the ltft's go into the negative then since the stfts are now positive as i drive or do i need to keep logging the maf and plotting the error and retuning?

[Russ K]

Ok cool will the ltft's go into the negative then since the stfts are now positive as i drive or do i need to keep logging the maf and plotting the error and retuning?

No, the LTFT's will go positive to bring the STFT's back to 0%. Just disable the LTFT and tune the Maf to get the STFT's slightly negative, then re-enable the LTFT's.

Russ Kemp

[02pewterz28]

No, the LTFT's will go positive to bring the STFT's back to 0%. Just disable the LTFT and tune the Maf to get the STFT's slightly negative, then re-enable the LTFT's.

Russ Kemp

Ok Russ so I got the new tb in the mail. Went and put it on and after a little more startup airflow in the table it starts just fine and also has a hot iac count of 35 or so. I havent had it cold so well see what happens then. Anyway I made some adjustments to the maf curve while idling and heres what I got this is with LTFT's disabled and just the changes to the maf.

I also did a couple wot runs with the 102 tb and the maf correction factor above 4000 rpm is still 0 just as it was wiht the 92 and the map is also at thre same 98-100 kpa as before. So it shouldnt effect the tune as far as I know since the error was zero and there was no change in manifold pressure correct? So far I actually like the snappier response of the 102 along with the softer pedal the nw has over the fast.

So I suppose now the next step is to get the RAF correct with a cold idle log? I'm still having issues with the car wanting to die when pushng in the clutch especailly at low speeds and also while just blipping the throttle at a stop. This was present with the 92 also so can we correct for that after the raf gets inline? I attached a scan of this also, however it was before the final maf calibration but should still illustrate it fine.


maf log 2.hpl O2pewterz28-1 (1) revision.hpt
102 tb scan 1.hpl

[Russ K]

First off, you need to return the high octane spark table back to the way I had it set up for you. Your going to damage pistons with your over advanced spark.

Your fuel trims will go to 0 at higher rpm because your in PE. Your Maf table still needs work, and a wideband is needed to tune the WOT fueling. And you need to delete unnecessary pids to keep the bytes to no more than 24 to speed up the frames/sec. And your 102 tb scan is of no use as your not logging any of the idle pids, other than the IAC.

Russ Kemp

[02pewterz28]

First off, you need to return the high octane spark table back to the way I had it set up for you. Your going to damage pistons with your over advanced spark.

Your fuel trims will go to 0 at higher rpm because your in PE. Your Maf table still needs work, and a wideband is needed to tune the WOT fueling. And you need to delete unnecessary pids to keep the bytes to no more than 24 to speed up the frames/sec. And your 102 tb scan is of no use as your not logging any of the idle pids, other than the IAC.

Russ Kemp

Sorry russ thats not the one in the car, the one in there does indeed have the max timing set to 24 or whatever it was in the other file. I was copying and pasting and got it mixed up....Tomorrow morning I'll get the logs of whats going on with driveability and delete the unneeded pids.

What areas should I concentrate on for the maf table? As a whole? Or in the lower hz ranges? Would you just recommend I drive around for 20 minutes and try to hit all the low cells? When it got dynotuned for wot with the 92 it had a 12.5 afr all the way. I will be picking up a wideband in the future however would the 102 really change it all that much? I was thinking that since the map didnt change at all and the maf seemed to read about the same it would be ok. What is the effect of the 102 if any then at wot would it tend to lean the motor out causing the pcm to dump fuel and then go rich?

[02pewterz28]

I know the maf cailbration error will never be 0 as the stfts are always changing so do I just drive around logging and then make a general change according to the error then redrive to see if im in the negatives

[Russ K]

Tune the Maf up to 6500-7000 Hz, then in 2D view smooth any bumps or spikes in the Maf curve. Make sure that you reset the LTFT's each time and bring the engine to operating temp before scanning. Also disable the DFCO before tuning the Maf.

Not sure if, or how much the WOT AFR will change with a 102 vs 92mm TB. Just because the WOT Map is the same, there could still be more airflow. But the Maf should measure the extra airflow.

Russ Kemp

[02pewterz28]

Tune the Maf up to 6500-7000 Hz, then in 2D view smooth any bumps or spikes in the Maf curve. Make sure that you reset the LTFT's each time and bring the engine to operating temp before scanning. Also disable the DFCO before tuning the Maf.

Not sure if, or how much the WOT AFR will change with a 102 vs 92mm TB. Just because the WOT Map is the same, there could still be more airflow. But the Maf should measure the extra airflow.

Russ Kemp

Ok sounds good so when you say the maf should measure the extra flow does that mean as long as the calibration up there was correct it should compensate fine? I didn't change anything in front so I would think that the airflow would be limited to the tubing in front which was smaller than the 92 to begin with.

Anyway am I only logging the maf to 7k because that's when wot fueling takes over? Should I only be logging stfts for this or do the combined st+lt? I found this link searching and was wondering if this is a good way to go? Sorry for all the questions Russ just trying to learn and it's definetley a slow process to say the least haha
http://www.hptuners.com/forum/showth...PICS&styleid=4

[Russ K]

Like I said before, the Maf should measure the extra airflow. But I wouldn't bet on it seeing how your tune was. Yes, logging up to 7000 Hz can be done without going into PE. And again I said you can add a user defined LTFT+STFT pid into your Maf histogram, or disable the LTFT's and just use STFT's.

I looked at that link and I'm not sure if it will help you much. Just copy the Maf histogram up to 7000 Hz and paste special multiply by % into the matching cells of the Maf table in the editor.

Russ Kemp

[02pewterz28]

Like I said before, the Maf should measure the extra airflow. But I wouldn't bet on it seeing how your tune was. Yes, logging up to 7000 Hz can be done without going into PE. And again I said you can add a user defined LTFT+STFT pid into your Maf histogram, or disable the LTFT's and just use STFT's.

I looked at that link and I'm not sure if it will help you much. Just copy the Maf histogram up to 7000 Hz and paste special multiply by % into the matching cells of the Maf table in the editor.

Russ Kemp

Hey russ heres the histogram I built using what you said. The log 3 file was the 3rd log I took and the 2nd set of changes after i made an initial run. All runs including this one were made with no DFCO and the ltft's off. I then used the special paste feature and multiplied by % half. The last one labeled maf 4 had dfco off but I enabled ltft's and did a final log. Most of them are pretty close. I didnt change anything over 6800 as that was pretty inconsistent from run to run. I made the same changes using that log.I'm going to do one more with ltft's enabled just to see and make a last correction...thoughts?

maf log 3.hpl maf 4.hpl Maf tuning.hst

[Russ K]

Looks close, but add 2% to the 3625-6750 Hz Maf table cells. And open your TB to lower the IAC counts to under 20. Also add the spark timing back to your .cfg file.

Then your ready to do a cold start idle scan.

Russ Kemp

[02pewterz28]

Looks close, but add 2% to the 3625-6750 Hz Maf table cells. And open your TB to lower the IAC counts to under 20. Also add the spark timing back to your .cfg file.

Then your ready to do a cold start idle scan.

Russ Kemp

Cool thats good news lol. I actually made corrections based on that last file with the ltft's enabled.....big mistake it threw it all off I labeled this "wtf log" lol did it get so thorwn off since i let ltft's start correcting again? Should I leave the ltft's off for good or renable them?

Anyway took the tune that made the log file (the close one) above and added 2% just as you said. Below the one labeled test tune 2 is the one I will load in today which is the one from the log with the 2%. The other is the original one you made so you can see the differnces. Spark is back into the config, and not to question but why do I want the iac lower? I thought the golden range was in the 20-40 range?

wtf log.hpl

O2pewterz28-1 test tune 2 hpt.hpt

O2pewterz28-1.hpt

[02pewterz28]

Cool thats good news lol. I actually made corrections based on that last file with the ltft's enabled.....big mistake it threw it all off I labeled this "wtf log" lol did it get so thorwn off since i let ltft's start correcting again? Should I leave the ltft's off for good or renable them?

Anyway took the tune that made the log file (the close one) above and added 2% just as you said. Below the one labeled test tune 2 is the one I will load in today which is the one from the log with the 2%. The other is the original one you made so you can see the differnces. Spark is back into the config, and not to question but why do I want the iac lower? I thought the golden range was in the 20-40 range?

wtf log.hpl

O2pewterz28-1 test tune 2 hpt.hpt

O2pewterz28-1.hpt

One other thing was I supposed to have VE disabled as well when I was making those logs? I didnt see anything mentioned about it here but other threads with gen iv motors all say to diable the ve's when tuning the maf

[02pewterz28]

maf log 5.hpl

took this on the way home. traffic sucked so i could only hit a few cells i think this looks good though and should be ready for the idle config? this is with your 2% added in russ using stfts here only lt's are off

[Russ K]

Ok, you need to add 5% up to 3000 Hz and your lean at 5500 & 5625 Hz. But I'm sure that your going to lean at the higher Hz cells, so scan to 7000 Hz.

Leave the VE alone, your in Maf mode.

You want the IAC lower to help with cold starts.

Russ Kemp

[rpturbo]

Russ, hey, I just wanted to say "Thanks so much" for the help you provide here. I have been following this thread, trying to learn like so many others. I wanted to ask, is the HO/LO tables in this tune, pretty solid as far as a timing table goes? I have been trying to figure out some of that, but can't seem to find any tables that I can trust to use for a baseline. Thanks for any info, and sorry for the thread whore.