Be gentle with me!

[gto_in_nc]

Hi, All!

I am a new ELILive owner (FedEx delivered my FlashScan V2 Scan & Tune a week ago today) and have just gotten my forum account activated (thanks again, Tordne!) I am the proud owner of a 2004 Pontiac GTO (Quicksilver w/ red leather and a 6-speed, FWIW) and an active member over at ls1gto.com. I currently have a set of Pacemaker tri-Y headers w/ cats and a K&N intake (and 275's in back) but more mods are in the near future as the car comes off warranty this month. Next will be WBO2 (very soon!), probably followed by a little "pssst" since it is sort of low-hanging fruit (plus Nitrous Dave makes a sweet little hideaway switch plate for the GTO!)

Anyhow, just wanted to say "Hi!" :cheers:
Brian

[joecar]

Brian, welcome to the forum... :cheers:

Joe

[Doc]

Hey Brian,
Have you had a chance to check out the tutorials yet? Custom OS #5 works great for the Psst!

[SSpdDmon]

Welcome...

[Redline Motorsports]

Welcome to the board! I also recommend the tutorials as well as many nights snooping the forum. The support on this site is fantastic!

Howard

[gto_in_nc]

Hey Brian,
Have you had a chance to check out the tutorials yet? Custom OS #5 works great for the Psst!

I've been looking through the tutorials but haven't spent much time on the custom OSes. Until I get WB, I am doing little but logging, although I have been nudging VE up in accordance with RPM vs MAP LTFT mapping. (Boy! The stock tune was WAY conservative, huh?)

I've also been looking closely at odd bits of KR that I am seeing that I think are spurious - looks like it will pull a small amount of timing if both banks happen to be at a trough in their oscillation when the throttle is stabbed.

I think I am ready to pop in a wideband and get serious! :beer:

[gto_in_nc]

Welcome to the board! I also recommend the tutorials as well as many nights snooping the forum. The support on this site is fantastic!

Howard

I've actually been lurking for some time and have been spending far more time on the forum than I care to publicly admit for the last few weeks! I am quite favorably impressed by the level of knowledg and the friendly willingness to help to I saw here. This was, in fact, a significant part of the decision-making process for me in selecting EFILive over its competition! I look forward to learning from the multitude of people here more knowledable than I am, and I hope to be able to contribute in a positive way myself in the not too distant future.

[TAQuickness]

Welcome to the forum. As soon as you're ready, start asking away. As you've noticed, there are a lot of folks here that like to help.

[gto_in_nc]

OK, let me ask THIS one, then! ;)


I've also been looking closely at odd bits of KR that I am seeing that I think are spurious - looks like it will pull a small amount of timing if both banks happen to be at a trough in their oscillation when the throttle is stabbed.

Am I correct? (Or close?) I'm talking about in closed loop, when the O2s are going "rich-lean-rich-lean", and then I quickly roll in throttle and see a small KR spike. It looks to me like the PCM sees both banks showing low voltage and says "Uh-oh! I'm lean!" and starts to pull timing, only to immediately roll back out of KR...

[TAQuickness]

this is on an otherwise stock engine/tune?

[gto_in_nc]

Yes. (Well, with headers and a K&N but otherwise untouched.)

[gto_in_nc]

Here's an example, from one of my very first logs (before I changed ANYTHING!) The inspector is on the moment right before it kicked in about 4 degrees of KR.

http://forum.efilive.com/attachment.php?attachmentid=1371

[TAQuickness]

are you sure the headers are not banging or touching anything?

[gto_in_nc]

Hmmm... That's definitely something I need to look into.

Here's another example, from just a few minutes ago. This one shows that it pulled only 0.6 degrees...

[SSpdDmon]

Knock retard is timing pulled based on feedback from the knock sensors, not the O2 sensors. If you see a lean condition and a small amount of KR, chances are it's the lean condition causing a slight amount of ping that triggers the knock sensors. That's assuming potential issues like a banging exhaust (as mentioned above) are not present. You could try to richen the mixture to see if the problem goes away. However, here we are dealing with closed loop, which means the PCM is in control of the AFR by trying to maintain 14.63:1. If this is something you see rather consistently, I'd back timing off a little in that region (keep in mind the interpolation that occurs).

Don't confuse this with burst knock and it's settings. Burst knock is timing pulled based on changes in airflow in the anticipation of knock. IIRC, burst knock retard does not show up under the GM.KR pid. If you stab the throttle and are seeing knock, you could try playing with the burst knock tables to see if that helps some. But, only after having dialed in the fueling so your not band-aiding over a lean tip-in issue.

That's my $0.02 at least...

[gto_in_nc]

That makes sense, SSpdDmon. I will get the car on a rack at a muffler shop soon to see it it looks like I may have contact. In the meantime, more monitoring! (And I think my personal sense of urgency for wideband is increasing...)

UPDATE: Just visited the guy who put my headers on. We put it on a rack and see no signs of contact nor places where contact seems likely. That's one thing eliminated. This KR is infrequent and small so I'm not going to obsess about it (especially since it probably isn't anything new...)

I've decided to order an LC-1 right away and have him install it for me as he is familiar with them (and he reminded me that I already have an extra pair of front bungs.) I'm gonna have him put the car on the dyno after the WB is in place and do a WOT tune. Then I'll start working on my partial-throttle/CL.

BTW, thanks for ringing the clue-phone, SSpdDmon, about burst knock retard not showing on gm.kr. I think I knew that but wasn't getting it.

UPDATE2: WB ordered.

[gto_in_nc]

Hey Brian,
Have you had a chance to check out the tutorials yet? Custom OS #5 works great for the Psst!

So, would OS5 work on my PCM??? I've got OS 12587604.

[joecar]

See post #48 of this thread: showthread.php?t=2599&page=5 (http://forum.efilive.com/showthread.php?t=2599&page=5)

You would need to change OS to 12212156 and then change to COS5.

There was an updated .cal file, see post #114 of this thread: showthread.php?t=2599&page=12 (http://forum.efilive.com/showthread.php?t=2599&page=12)

[gto_in_nc]

Perfect! Thank you, joecar. Not there yet but...

I think my plan is as follows:

WB in service within next two weeks
Iterations of logging & AutoVE until :D occurs
:beer:
Turn attention to spark
Return to step 2 :)
:cheers:
Decide what to do next (maybe OS5 followed by dry shot...)

[gto_in_nc]

I am now approaching step three, above (OK, actually, step two would be done by now if I hadn't occasionally slipped into step 3 prematurely but there's this place down the street with 110 beers and a "world beer tour"...)

On a 50-count minimum, my BEN is now mostly in the 0.98 to 1.02 range. What is most surprising & telling, I think, is what my injectors have done. Prior to tuning, the thing was pig-rich, with injectors hitting 85+% at WOT at redline. Now they are just under 75%. Crispness is substantially improved, too. I think a long cruise this weekend ought to give me the data to finish this round of VE tuning.

What should I do next? Look to MAF tuning? Follow the plan above with :beer: followed by spark tuning? Play with lean-cruise, perhaps? (My '04 GTO is a Holden at heart, you know...)

Suggestions???

[SSpdDmon]

MAF next....yes. Based on your current mods, it's probably off by about 5% on the top end. So, I'd increase the stock MAF table by 5% from ~5,000Hz on up and blend in the change to the lower range (ie increase 4875Hz by 4.75%, 4750Hz by 4.5%, etc.). Then, dial it in using the BEN factors. The tricky thing I noticed is, you only need about 65~75% of the BEN correction. So, if you can alter it before you apply it, that might not be a bad idea. ;)

With exhaust being your only mod, there's not usually a whole lot of timing adjustment needed. Ideally, you want to do WOT adjustments on a dyno after you have your AFR dialed in. IDK if you have the same stock cam that my '02 had. But if you do, chances are you're not going to be able to run more than 22~23* before peak torque, 18~19* at peak torque and 23~24* on the top end.

[gto_in_nc]

The '04 GTO had the same came as the '01-'02 F-bodies so your guidelines should apply for spark, I think. (BTW, I think maybe I want a new cam... :D )

MAF tuning it is, then! (Once VE is close enough to call "done" for the time being.)

Thanks!

<scurries off to do research on MAF tuning>

BTW, I'll just set up a little Excel transformation pre-paste to reduce the weighting for the MAF adjustment. I did that with the AutoVE routine to allow less frequently hit cells to still have a small contribution to the adjustment in the first couple of passes.