Throttle Cracker Tuning Question {B4309}

Hi all,

I've gotten my tune in a pretty good spot. I've gotten rid of almost all my bucking, surging, hunting, and stalling issues after installing a big camshaft. I'm looking at the throttle cracker table now, B4309. I have attached my current tune and latest log where I was looking at this predefined map for B4309.

When tuning this table, can I do a log, open the B4309 map, then copy/paste it into my tune? That seems too easy. I've been able to manually adjust it where I have bucking issues, but if there's a way to add some automation to my life I'd like to try it.

I've gone through a couple idle tutorials, and neither mentions any adjustments besides making tweaks and trying them. I'm not opposed to this method, but if I can gather data and use that it might make life easier. Below are the tutorials I followed:
https://forum.efilive.com/showthread...ul-Info-Inside
https://forum.efilive.com/showthread...ips-amp-Tricks

I have a 2004 GTO with the 5.7, it has a fairly long duration cam (Summit part number SUM-8700, similar to the ASA cam of the day). It also has an over-the-radiator intake and full exhaust.

From the data log below, I applied a filter to only show operating temperature and no throttle input. Most of the cells in my B4309 map end up being 0.00 or near 0.00. My thinking was modifying the throttle cracker table with values where only the throttle cracker is active and the throttle follower isn't.

I've done RAFIG a few times and it's pretty spot on, the car fires right up and seems like it's getting the right amount of air. I shifted the IAC area table so IACDES_B and DYNCYLAIR are the same at operating temperature when idling prior to completing the RAFIG process.

Throttle cracker data log:
Attachment 22558

Latest tune:
Attachment 22559

I'm looking at this closer... do you have the previous .ctz file so I can see what you did.

Not a problem! I have attached my stock tune below. The big changes are the camshaft and the air intake (not intake manifold).

I'm hoping I can get some direction on how to use the Throttle Cracker map in the scan tool, although any other pointers are appreciated!

Bone stock tune:
Attachment 22572

So I've been trying to do more research. From what I've gathered comparing my stock (or modified) GTO tune to a C5 or 4th gen, some of my airflow decay and/or delay tables are quite a bit different.

I've gone through the tutorials on this forum a few times. I think the next step I want to take is to run back through my spark tables to make sure those are in check. I found a base tune for an LS1-M6 (my combo) with a mild cam and some other minor bolt-ons. I found the tune here at the bottom of post #1: https://forum.efilive.com/showthread...l=1#post129525

Looking at the base spark table, the commanded spark at idle is 1* off what I have, which makes sense. This tune also has much more timing below idle RPM, which would help prevent stalling.

Looking at post 1 of the idle tuning thread from SSpdDmn, seeing some of his posts and Swingtan's posts from a few years ago, the 4th gen F-body airflow tables are a solid place to start. I haven't seen anyone say that about the GTO tune, so I'm a little suspect of it. I have heard negative things about Holden tunes, again adding to my suspicion. SSpdDmn's throttle cracker table is set to 0 around the RPMs where I have some bucking (I'm chasing low-speed driveability right now). Here's his thread: https://forum.efilive.com/showthread...ul-Info-Inside

So I'm inclined to do the following:
1. Try the base spark table from the LS1-M6 base tune, go for a drive and see how it goes.
2. Copy the throttle cracker/follower and their decay/delay tables from that same tune, go for a drive and see how that goes.

Thoughts on that?

Quote:

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Originally Posted by pinstripebob

I have heard negative things about Holden tunes, again adding to my suspicion.

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Yeah, as a Holden owner I can confirm that the stock Holden tunes suck. But let's not dwell on the negatives, lets look at the positives... Holden tunes have left plenty of room for improvement. :laugh:

Quote:

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Originally Posted by pinstripebob

So I'm inclined to do the following:
1. Try the base spark table from the LS1-M6 base tune, go for a drive and see how it goes.
2. Copy the throttle cracker/follower and their decay/delay tables from that same tune, go for a drive and see how that goes.

Thoughts on that?

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Just blindly trying things out is sometimes a good thing (when you see the effect of changing tables, it can help you to learn about those tables)... but remember to always log for KR.

Consider the basics, Throttle Cracker is controlling the IAC valve when you are on the throttle. Throttle Follower is controlling the IAC valve when you are off the throttle. So my first question is in what condition, on throttle or off throttle or both is when the trouble is happening? Next thing to consider is the minimum timing table. What are your low crusing #'s in the minimum timing table. You have to think about this process like leveling a tripod. Air/Fuel/Spark have to be balanced. If one of the three is right but one of the other two are off base you will find the outcome you are describing. I take it you have already performed AutoVE on the MAP and MAF? That's a good start. When scanning the trouble spots keep a keen eye on IAC, Fuel Trim, and Timing.

Statesman, good call on checking for knock! I've been monitoring KR and had to lower a few areas of my high/low octane spark tables.

Doc, seeing that written out and reading it helps out. I think I've gotten a bit of tunnel vision going after the throttle cracker and follower tables. I'm trying to get my low RPM/low load bucking to go away. The condition exists under 2,000RPM, in gear, under light throttle OR under no throttle. So throttle cracker and follower should need some attention.

I've been cruising around 34.5-35.0 degrees, although now that you ask and I look at my log/tune side by side it looks like I should be at 36.89 at .28g/cyl and 1800 RPM (frame 2460 in the log). Although, the spark table does some interpolating between cells, right? Minimum spark advance is still stock, about -12 or -6 at cruising speed/RPM.

I have done CALC.VET and gotten my MAF pretty well dialed in. My fuel trims aren't bad, but my wideband sensor died before I could do more VE table tuning. I got a new sensor, hopefully I can get it put in this weekend.

From my last post, I've done the following:
1. Modified my base spark table, bumped up idle spark a degree, bumped up 600/400RPM cells quite a bit to act as a stall saver (engine liked to try dying doing parking lot maneuvers).
2. Reduced high/low octane tables any time I logged knock.
3. Reduced throttle cracker cells 5% at a time whenever there was bucking and I was off throttle. Also bumped up 400RPM cells to act as a stall saver.

I should note that bucking is GREATLY reduced at this time. I'm a pretty happy camper, it seems like I'm moving in the right direction. I suppose there aren't any good uses for EFILive's preconfigured throttle cracker and follower maps in the scan tool?

Current log, city/highway/city driving:
Attachment 22578

Current tune that generated the above log:
Attachment 22579

There's not enough in that log for me to see what's happening.

Do another log. Log all the things you logged last time and add these PIDs...

GM.IAC
GM.VOLTS
GM.MAFFREQ
SAE.SHRTFT1
SAE.SHRTFT2

And yeah, I don't care if you blow the 24 channel count.

So many channels!!

I should be able to snag a log on my way in to work, no problem.

Sent from my Pixel 3 using Tapatalk

Don't forget to pay attention to the timing as well. Remember the fire triangle. Especially in the low cruising areas you have mentioned. Stock timing cells are pretty high for a bigger cam.