P01 computer on LQ9 Timing Issues

[weinerschizel]

I dialed in my VE and MAF tables. Then put them back into my closed loop tune and loaded to computer. There's some issue though. I built the engine from scratch and used an old P01 Computer from a 5.3L engine. I now have a 6.0L engine with mild cam and basically solid lifters (2116LSR short piston/pump).

I'm not sure what to do here. I got the truck running (though not well) with 5.3L tune and started working from there. I pulled a 2002 Gen III LQ9 w/ P01 computer tune of the HP Repository. I then copied the idle tuning and few other items over into the 5.3L tune along with my VE and MAF tables. Otherwise the engine didn't idle well and wouldn't drive.

I've got it running however, now my issue is spark timing. I copied the spark tables from the LQ9 tune into my tune. I got some knock so pulled timing in those areas and started smoothing the table. It well runs like crap. Cannot even merge on highway. Should a person even tweak timing? I'm following goat rope garage tutorials but he's about the only one I can find with any info on it.

1. How do I get a KNOWN good timing table for Gen III 6.0L LQ9
2. Am I going to blow my motor up if it knocks a bit while I'm adjusting timing? Is this a bad thing to adjust? What are rules of thumb? No higher than 40 degrees or lower than 32? Not sure...
3. Would my camshaft changing timing from stock very much? It's this, 0.578" Intake 213 / 0.587" 220 Exhaust. Lobe separation is 114+4A (custom vinci cam #562)

Attached is my current tune with timing issues. It's a hybrid of the 5.3L and 6.0L tunes.

SPARK R2 K.hpt

[kevin87turbot]

You are not going to blow up anything with that timing table. It's crazy low under load. You'd be better off copying the stock LQ9 High Octane Spark table to both your High and Low Octane tables. Then dial in your VE table. With your high performance cam, you should be able to safely add even a few more degrees ignition timing at lower rpm.

[weinerschizel]

Cool, I am one step ahead haha. I swapped in LQ9 tune from 2003 Silverado SS. Seat of the pants dyno makes me feel a bit under power down low yet as you mention with LQ9 map. However, I'm getting a little knock 2400+ 0.3ish+ (something like that).

Thanks for help. Attached is where I'm at now.

SPARK R3 B (LOW OCT = HIGH OCT).hpt

SPARK R3 B.hpl

I'll fidget some more. I'll make a tune with under 2400 RPM copied from the high octane table to low octane table and use that before I bump up the under 2400 RPM much more. I want to figure out what's going on after 2400 RPM so I know I'm at a safe place to hammer on it and figure more out.

Curious how do you know when you're starting to get into trouble...? I just don't have any experience with this so want to know how to play it safe. Thanks!!

[kevin87turbot]

That's still extremely low timing under a load. It averaged around 13 degrees when you approached WOT. If you're running 87 octane, you can easily add 6-7 degrees. If you're running 93 octane, you can add 9-10 degrees...and still be safe. Before you add timing, lower the torque threshold and TPS thresholds for PE Enrichment. Then add timing. I'll attach an LQ9 file so you can copy the High Octane timing table from it.
2006cadillacescaladejackieeStock.hpt

[weinerschizel]

Awesome thanks @kevin87turbot. Really appreciate it.

Is that 6 to 7 degrees across the map? Or just down low?

At what point (too much advance) do you experience diminishing returns for power? 50 degrees?

I'm curious I registered some knock with the low octane spark table. Do you think knock was due to something else?

Attachment 110775

[kevin87turbot]

Typical timing values for an LQ9 are 16-20 degrees at idle (depending on cam size and application.) Light throttle crusing will be 20-30 degrees, decel will be 35-45 degrees, and at WOT, 20-25 degrees...again depending on application and fuel that's being used.

[weinerschizel]

Super helpful thanks Just pump, 87 octane. Once in a year or less maybe 84 They sell really $hit gas up in the mountains of Canada / Alberta & BC. Not sure why.

[weinerschizel]

So I'm a bit nervous. I keep getting knock. It's somewhat random at where it shows up on each test run. I'd imagine I shouldn't get ANY knock with those factory spark tables. Last engine I built (LT1 / OBDI computer) had ZERO issues with factory tune other than idle.

Leads me to wonder if my airflow (fuel) tuning is wrong. I collected data for the airflow tuning with a 5.3L P01 computer I recycled on my 6.0L build. Long story, I used an old 5.3L config per advice I got online to get it running. It ran like crap but I could drive it and had no knock. That advice was absolutely TERRIBLE to use 5.3L config on a 6.0L engine.

With 5.3L config I got very little power down low even after dialing in MAP and MAF to within 2%. However, I had no issues with knock.

Now per your advice and others I took the 6.0L config and put my VE and MAF tables into it. Now however, I'm getting random knock. Sometimes the computer is pulling 6 and 7 degrees of timing. I wonder these are not issues with spark table but really fueling problems?

I have been logging wideband while monitoring spark. Most cells on VE histogram (datalogging) are within 1% with closed loop (those are averaged over the run). However, there are some as bad as 4 and 5% off. Especially around boundary of data log on chart.

Long story short, is it possible my fuel could be so far off it's creating knock? That I cannot copy and paste a tune created in 5.3L configuration into a 6.0L configuration?

Just super nervous I'll burn out my engine build.

[kevin87turbot]

If you're within 5% error on you fueling, then you've got a good start for VE/MAF tables. It's plenty close that it will not cause knock. It's very likely false knock (possibly caused by a mechanical noise or even a bad knock sensor.)
Does the recorded knock go away when you increase the fuel octane?

[weinerschizel]

Thanks Kevin for the help

I rebaselined everything to the 2003 Silverado SS LQ9 configuration including my MAF and VE tables. I did some test driving. I got a knock on highway after accelerating up to speed but none driving conservatively on city streets. It seems even from prior to tunes it was always around the same area where it pulled timing.

Knock Sensors: I have two brand new knock sensors and wiring harness. Not to say they are good, was just something I replaced with the new engine build. Is there any reasonable way to test them without taking the intake manifold off?

Testing fuel octane: I want to do as you mention. I'm getting low on gas. Next tank I'm going to fill up with highest octane gas station sells by my house (I think it's 93). Then see if the knock goes away. Will report back on that.

Attached below is my current tune file along with that test run.

T01 silveradoSs (LOW OCT = HIGH OCT SPARK ADVANCE).hpt

T01 R00.hpl

[weinerschizel]

Best they had at my gas station was 91 octane for an arm, a leg, and a kidney. I filled up on it. 18 gallons of 91 octane to top of tank that had 8 gallons of 87 octane.

I drove around 20 miles on the tank. Still knocking, however, completely inconsistent with where it knocks at. I could hit the same cells again not to have knock there the next time.

I wonder if... I'm not getting this knock from somewhere else. My transmission likely has 240k on it. Building a new one but not ready yet. Same goes for AC compressor and other accessories (minus water pump).

I turned off the AC then beat on the truck. Drove it like I stole it. But under 30MPH. I lit the tires up from a roll (pretty damn cool), manually shifted transmission, clicked the tow haul button on and off. I hit a BUNCH of the same cells as has formerly registered knock. NONE REGISTERED knock.

Curious, if it's true engine knock, should I see it consistently? Registering in same cells over and over again (engine RPM vrs cylinder pressure).

[kevin87turbot]

Now you're getting somewhere. I agree that it sounds like it is related to a mechanical noise from the AC compressor. Have you had any audible knock? Is the AC compressor noisy?

[weinerschizel]

No audible knock what so ever. However, when I charged the AC system I had some weird noises in compressor. They were especially audible when I put a mechanics stethoscope on it. I got the system to pressure though and couldn't hear them anymore with the stethoscope.

I also noticed with the 5.3L tune, the truck wouldn't run well with the AC on. It didn't register knock per say but at idle w/ brake applied in drive, the AC would cause spark to oscillate 20 degrees until I let off the brake and gave it gas to start moving.

I see there's tables to tune AC stuff... I just copied and pasted them from the LQ9 table, but I wonder if there's more to it than that... and or if my AC compressor is on it's death bed. It's pressures are good, blows cold air, etc, and with good charge doesn't make noise. That said, I can in some instances, turn on the AC w/ truck in gear and brake on and have the engine stumble and turn die.

Long story short, it's FN hot here (110F right now). I may watch and see if I only get the knock with the AC clutch on / engaged.

[weinerschizel]

I may have figured this out...

- Put in 91 octane gas. Knock persisted.
- Tried driving with and without AC knock persisted.
- Saw events starting at 0.48 cylinder pressure, so 0.48 and above I removed nearly 6 degrees of timing and added 5% fuel across board. Knock persisted, magnitude of which remained unaffected.

Next I decided to start logging what gear I was in. Knock almost always seemed to follow shifts. I drove around trying to educe gear shifts after I noticed this. My knock magnitude increased as I did it. However, was surprised transmission temperature wasn't rising. I dug deeper. Selecting 1st gear didn't seem to have any effect on knock. Next forced 2nd gear through VCM Scanner. Applied throttle on slight incline. Once rose above 0.48 cylinder pressure the knock started to come back. And then transmission temperature did rise a little bit. I then forced direct drive / 3rd. No knock.

I suspect my 2/4 band is slipping. Amazed, that makes enough noise for the knock sensors to pickup? I can sometimes feel it in the pedal when it does it. It's a vibration and hesitation to accelerate. I think I may have laid this post to rest.

4l60e clutch chart.jpg
T03.hpt
T03 R01 GEAR FIDDLE.hpl

[kevin87turbot]

Good job figuring that out! It certainly makes sense.

[weinerschizel]

Thanks, I always doubt myself. Will know much better once I can assemble and install my new transmission.