Timing Blips, Shudders at Speed... Caused by What?

[kingtal0n]

Can’t everyone just get along?

This is the process I've become accustomed to,


1. He will lie and slander, just make something up throw dirt wherever I post in a thread

I would completely ignore that guy. Few weeks ago he didn't even understand the definition of VE.

https://forum.hptuners.com/showthrea...l=1#post757887



Literally just says whatever he wants, makes up a lie unfounded. And I am forced to defend myself each time. How can I l allow such blatant lies? Clearly I can not stand that and should not be expected to either.

2. The defense article
From 2013
https://www.sr20-forum.com/tuning/!2...75#post!922675

This is due to a dropping volumetric efficiency. Extra timing is safe when the VE (torque) is falling off.

From 2003
https://www.thirdgen.org/forums/powe...ml#post1270941

Yes, peak torque and VE do happen at the same point, but that is because the torque curve and VE curve are the same curve. If your engine ran at 100% VE all the time your torque curve would be a flat line with the same value (ex, roughly 399lb-ft for a 350).

Then they complain about me when I defend by showing evidence that makes them a liar. They know they got caught lying again and its just a habit so they keep doing it, there is no punishment for lies so why stop.

[squeeler642]

Here. If you want to stay GM settings this is the limit. LQ9 knock settings applied. LQ9 is the same block as the LQ4. It's just one table (take a guess). The knock settings are all the same for the Escalade and Silverado SS models equipped with that engine.

Same knock sensor part number as your 2003 Tahoe.

PE settings applied.

Let's see it in a log.

I took this for a ride a little earlier. What do you think of the knock? Real or fake?

Here's the original KR table vs the one from today. IIRC, this is the same tune (timing wise) with your PE multiplier and stock LQ9 knock sensor settings. Looks pretty similar to me.

IMG_20231208_200547.pngScreenshot 2023-12-09 160841.png

[SiriusC1024]

Looks real to me. On the bright side the TIP In KR isn't present.

[squeeler642]

Looks real to me. On the bright side the TIP In KR isn't present.

Yeah I had the same thought. Running around town so I'll let you know how this one goes. Why the sharp dip in the table around the KR area? I would think we'd be bettwe off smoothing out that area of the table instead of putting a trough in there like that. Just curious.

Also... is knock more prevalent after cold start? I didn't save it (fat fingered the save button) but the first log I recorded today had a little more knock than the log I uploaded.

[squeeler642]

Here's log #1.

[SiriusC1024]

That type of dip is common on factory files. Look where GM decreased TIP In sensitivity on the LQ9. Same area we're focused on. Something inherent to the design makes it knock prone here. That we're seeing this reflected in KR is yet another indicator that knock sensors are working correctly, and that we are getting to the limit of your particular build.

Here's a 2006 TBSS Hi table (LS2):
TBSS HI.png

And a 2000 Corvette Hi table (LS1):
2000 Corvette Hi.png

Changes to latest revision based on KR (LQ4+.040+mild cam):
Dyn 3 Hi.png

About the cold start KR I'd need to see it logged to give a good answer.

Sorry about the repost. Images weren't attaching inline correctly.

[SiriusC1024]

Here's log #1.

167F isn't much of a cold start.

[squeeler642]

That type of dip is common on factory files. Look where GM decreased TIP In sensitivity on the LQ9. Same area we're focused on. Something inherent to the design makes it knock prone here. That we're seeing this reflected in KR is yet another indicator that knock sensors are working correctly, and that we are getting to the limit of your particular build.

Here's a 2006 TBSS Hi table:
TBSS HI.png

And a 2000 Corvette Hi table:
2000 Corvette Hi.png

Changes to latest revision based on KR:
Dyn 3 Hi.png

About the cold start KR I'd need to see it logged to give a good answer.

Sorry about the repost. Images weren't attaching inline correctly.

Very interesting. Still trying to better understand how the KR-prevention PE-mult table and spark tables are interrelated. Order of operations seems like it would get you different results based on which table you start setting up first.

167F isn't much of a cold start.

I know... talking about a run I didn't save/upload. Haha.

[SiriusC1024]

Next log include the tune file name with the date. So _Dyn_2, _Dyn_3, etc.

[kingtal0n]

when you see knock like this in the log

find rate
12.28.02 , 3000rpm 44mph

12.32.17 , 4200rpm 62mph

4 seconds in 18 mph

4.5 mph per second, 300rpm/sec

rate and power give heat accumulation. This vehicle have a slow rate and slow power rate of heating. For example power here is in a range where it won't make much difference to rate of acceleration because the vehicle is very heavy and the engine is very weak with no turbo, rate comparisons are more difficult and slight changes to power will have practically negligible influence on rate.


I would safely start with 9* at 3000rpm 0.73 grams per cyl air density. 12* by 3800rpm then back to 11* (the point of accumulated heating and peak cylinder fill through second gear) from 4000 to 5000rpm with the deepest pit at 4800-5200 at 10.5* and ramp in to 12 or 13 by redline. Interpolate vertical, columns so timing drops as grams per cyl increases.

Find new rate through second gear and confirm knock is gone. If rate is the same you are done. If rate is lower then

Increase timing by a degree or two if needed to restore original rate or better and reduce EGT peak and rate.

If knock persists at 9* it could be fake but you will decrease to 5* or 0* or put 105 octane fuel or whatever it takes to confirm the knock is fake.


Quick paint


The engine is designed to take some heat but the timing must be correct for the heated condition with recommended fuel. Twenty or even fifteen degrees in the 3000rpm ranges may not be suitable for such a low 200-300rpm/second rate at whatever compression it is.

[SiriusC1024]

One thing I think we can all agree on is NGK TR6 plugs. They are a heat range colder than factory. TR6 = copper, TR6GP = platinum, TR6IX = iridium. Pick a set and put them in, please. I'd at least opt for platinums.

[squeeler642]

One thing I think we can all agree on is NGK TR6 plugs. They are a heat range colder than factory. TR6 = copper, TR6GP = platinum, TR6IX = iridium. Pick a set and put them in, please. I'd at least opt for platinums.

So... what makes a colder plug help with detonation? Ordered a set of TR6s at O'Reilly's and will pick up today. Have seen everywhere that colder plugs help but am not really sure what the mechanism is.

[SiriusC1024]

Regular copper TR6?

Colder plug is literally colder. A hot spot can light off the charge prematurely. See above where KT is talking about the effect of heat increase during a sustained load. edcmat-l1 mentioned TR6 also. I run them in my HCIE build.

When you get the new plugs look down the ceramic surrounding the electrode and compare to the stock ones. The stock ones will be more hollow, and the TR6's will have more insulator material. That ceramic acts like a bridge to conduct heat away from the electrode to the cylinder head.

If the temp is too cold (don't worry these aren't) then the plugs will eventually foul.

[squeeler642]

I guess the heat causing detonation are the words I hadn't seen put together in this context. Whatever the case is, it's a $40 mod and I can run a little more aggressive timing, so I figure that's worth it.

Got just the regular TR6 plugs. All the other ones are similar... They're either platinum, iridium, or nickel plated over a copper electrode substrate. Nickel is cheaper and plates thicker (takes longer for the spark to eat thru into the Cu substrate) than either than platinum/iridium, and is harder than platinum. Probably explaining why people like them the most. Best bang for your buck, little difference in performance I would think, and lasts longer than the precious metal variants, especially for 2-3x the price over the nickel plated ones.

The way I see it... you pay for a couple microns of precious metal plated over the same copper as on the cheap ones. The cost of the plated metal is cheap, but standing up a plating process to make a smaller quantity of fancier plugs is expensive. Hence the added cost. Textbook law of diminishing returns example.

[SiriusC1024]

People like them for old distributor stuff with weaker ignitions and long wires. LS coils deliver more joules. Another plus is the thicker electrodes don't have a pointed tip that heats up as fast. Anyway, you're right about the plating; copper is the terminology for the nickel plated ones. Where you're mistaken is that nickel doesn't last nearly as long, so expect to change them out like tampons.

[squeeler642]

People like them for old distributor stuff with weaker ignitions and long wires. LS coils deliver more joules. Another plus is the thicker electrodes don't have a pointed tip that heats up as fast. Anyway, you're right about the plating; copper is the terminology for the nickel plated ones. Where you're mistaken is that nickel doesn't last nearly as long, so expect to change them out like tampons.

Bastards!! My order didnt go thru to O'Reilley's when I placed it. Decided to splurge for the good stuff... your tampon comment made me laugh out loud, after all. Figured it was the least I could do. Not sure I'm gonna have time to swap them in today or this week, might have to wait until next weekend. Where should we leave the tune in the meantime?

[kingtal0n]

I guess the heat causing detonation are the words I hadn't seen put together in this context. Whatever the case is, it's a $40 mod and I can run a little more aggressive timing, so I figure that's worth it.

Got just the regular TR6 plugs. All the other ones are similar... They're either platinum, iridium, or nickel plated over a copper electrode substrate. Nickel is cheaper and plates thicker (takes longer for the spark to eat thru into the Cu substrate) than either than platinum/iridium, and is harder than platinum. Probably explaining why people like them the most. Best bang for your buck, little difference in performance I would think, and lasts longer than the precious metal variants, especially for 2-3x the price over the nickel plated ones.

This is how you do plugs.
You buy 3x sets.
2x sets of copper cheapest NGK TRX
1x set of iridium NGK

First set of coppers goes in for tuning. Leave any oil you find in the threads on the head. Try not to touch the business ends of the plugs with your skin.
You tune the engine now how you want it. Tuning will deface and scar the plugs with a history of good and bad tuning efforts.

Once the engine is fully tuned, install second set of copper plugs. Drive vehicle as many miles as possible to accumulate history on the plugs from tuning.
Now after say 3k, 5k to 10k miles, remove all plugs for inspection. If the engine was actually tuned properly they will come out looking almost brand new, looking pretty good. Using narrowband closed loop will brown them up a bit but its fine to see slight tan discoloration in places. The ends should be clean visually. Here is an example of 4x coppers after 10k miles after the engine was tuned. Unbroken black carbon ring, no specks, flakes, spots, no melting, and heat went up the threads. These plugs were run at 15.2:1 idle and cruise which kept them looking newer and cleaner than a narrowband will.


Now that you are sure the engine is tuned properly, you can use the expensive iridium plugs.
There is a special procedure for iridiums.
1. Try to buy the correct gap, you can get a factory 0.027" or .039" as needed out of the box.
2. If you need to gap the plug, do not use metal or harsh instruments, do not hammer the plug. You must bend softly using a plastic tool to not deface the metal or scratch the metal materials on any electrode.
3. DO not touch the plugs with human skin, ever. Use brand new fresh disposable gloves to handle and install.
4. Clean the spark plug threads free from most oil using paper towels.
5. Apply very tiny around 3mm size droplet of anti seize near the top of the threads away from the end as high up on the threads as possible and spread there only near the high up threads. It will gradually ooze down over time and if you apply too much anti-seize here it will contaminate the electrodes eventually.
6. do NOT get anti-seize on the electrodes or anywhere other than the threads of the plugs as high up as possible towards the center of the plug.
7. PCV system must be correct: crankcase pressure must be below atmospheric at all times to keep oil out of the combustion chamber.

If the final set of iridiums goes in clean, no hand salt, no grease, no contamination, correct gap, undamaged electrodes,
They will last 60,000 to 100,000 miles in forced induction applications 600 to 800rwhp ranges. At 1,000rwhp dynojet I would recommend changing them around 40k to 50k miles though.
This goes for LS, RB, 2J, SR engines we all use the similar plugs from NGK and they all go high mileage if this is done correctly.
Point being the plugs should be a one and done thing once you've tuned the engine and switch to the high quality plug.

[SiriusC1024]

Bastards!! My order didnt go thru to O'Reilley's when I placed it. Decided to splurge for the good stuff... your tampon comment made me laugh out loud, after all. Figured it was the least I could do. Not sure I'm gonna have time to swap them in today or this week, might have to wait until next weekend. Where should we leave the tune in the meantime?

Put the Lo table from Dyn_2 into the Dyn_3 tune. Stay out of the power.

[edcmat-l1]

1. He will lie and slander, just make something up throw dirt wherever I post in a thread

I don't have to lie about anything. It's all here in your own words. You wanted to argue the definition of VE.

You constantly promote open loop tuning.

You posted your own tune and it's terrible.

You don't tune ETC cars. You admitted that. So that means you're not tuning and C6s, Z06s, CTS-Vs, ZL1s, LT4s, etc. In other words you aren't tuning anything nice.

You don't know that these engines benefit from oil separators in the PCV circuit.

Like I said and will continue to say, people should just ignore you.

Back to the subject, not sure why y'all are all caught up with the timing and knock retard in this thing. Isn't the combo a dished forged piston rebuild? If it is, deaden the sensors, put 26 degrees in it and let it eat. You aren't going to hurt it. Not a forged piston NA 9.8:1 compression build.

Oh yeah I'd still do a seafoam cleaning of the intake, install a catch can and put TR6s in it.

[kingtal0n]

I don't have to lie about anything. It's all here in your own words. You wanted to argue the definition of VE.

You constantly promote open loop tuning.

You posted your own tune and it's terrible.

You don't tune ETC cars. You admitted that. So that means you're not tuning and C6s, Z06s, CTS-Vs, ZL1s, LT4s, etc. In other words you aren't tuning anything nice.

You don't know that these engines benefit from oil separators in the PCV circuit.

Like I said and will continue to say, people should just ignore you.

Back to the subject, not sure why y'all are all caught up with the timing and knock retard in this thing. Isn't the combo a dished forged piston rebuild? If it is, deaden the sensors, put 26 degrees in it and let it eat. You aren't going to hurt it. Not a forged piston NA 9.8:1 compression build.

Oh yeah I'd still do a seafoam cleaning of the intake, install a catch can and put TR6s in it.

Let me see if I understand your 'logic'.

open loop tuning is 'bad' because its not how the factory does things.

however, Catch cans are 'good' because its not how the factory does things.

So which is it? You talk out of both sides of your mouth.
You call open loop tuning a 'hack' because it is not the factory way. But then you call catch cans 'not a hack' even though it is not the factory way.
Who put you in charge of what is a hack and what OEM way is good or bad?


If I say Catch cans are bad because the OEM PCV system works perfectly fine. And I have evidence.
And Open loop tuning is good because it allows a tune superior to OEM. And I have evidence.
The difference between us is I have LOGIC for my decisions and EVIDENCE for what I say being true. I've only owned 1 LS engine my entire life because thats all I need, its in perfect shape and clean because I know what I am doing, aka EVIDENCE. A stock engine at 600rwhp accumulating a hundred thousand miles and its my first one. Dammmn son I got you good didn't I

All you have is copy and paste from what everyone else is doing. Put a catch can because thats what everyone else does. Use closed loop because its factory and factory is clearly better than anything else. Oh wait that doesn't make any sense...



Seems like you just call something a hack when its not done the way you are doing it. And there is no logic or criterion or evidence. Not even math. I supply evidence and math model for my decisions. Other users have shown using 5-gas analyzer and dyno the same evidence. Yet you refuse to see it and just call it a hack because its not YOUR way. People should ignore you because you have no learning or logical capability and that is a dangerous copy and paste , full of errors.