Darth_V8r

iTrader: (4)

Your VE table matches a stock LS1 F-Body, which I see you noted. I don't think that is helping at all. I know it's a MAF only tune, but if the MAF fails, the VE tables are the backup. I also think that the timing table is hurting you at mid-load. Here is a tune that was done by a very reputable tuner on my car when it was basically cam-only. Should give you an idea what the timing and VE maps should look like. This was a "safe mode" tune, so the timing is not as high as a typical tune would be.

Honestly, you should look through much of this tune for a really good idea of what should be different and what should match stock. You can get a stock F-body tune off HPT website to use for compare purposes.

Lastly, here are some simple mechanical checks: spark plugs - if they are not TR6, try a set of TR6 plugs. Is your Y pipe catted? Are you sure the cats aren't plugged? Is your PCV bypassing a lot of oil? Those three items can be the cause of detonation as well.

RonSSNova

iTrader: (3)

His tune is also set for a max KR of 4 degrees when in PE mode.
I think that's why it see 4 deg of retard all the time.
But the setting is stock.

Thanks for trying my suggestions.

You need to set the low octane table to be the same as the high octane table. You car is running on the low table, I see it at 23 degrees right before it begins knocking.

And good you went to the new scanner. It's better! I see your AFR is now much more believable. :-)

I don't see any issues with your MAP sensor. And changing your PE Pedal back to stock is worth a try. It will get better economy, but I don't think it's the issue.

Ron

2MCHPWR

iTrader: (10)

wow . thats crazy. i had no clue but thank you. I will definitely try that ASAP.
Along those same lines, i hear a rattle near the muffler. I assume its the heat shield under the gas tank. Been wanting to remove that shield but just wanna confirm gas tank won't explode Do you think that small rattle could be heard all the way up there and could be reason of the KR?

2MCHPWR

iTrader: (10)

hi again - i do have a stock 98 camaro tune off the repository for comparison purposes.
I will put new TR55 plugs in (sitting on shelf); you noted TR6 but i thought tr55 was the standard.
Y pipe is not catted (off road).
I have the valve cover vent holes (pass and driver sides) going to a single catch can; haven't checked it lately but i will. thanks!!!!

Darth_V8r

iTrader: (4)

I don't know the answer to that question. I would doubt it. But a Y-pipe contacting the heat shields up front I could certainly see being "heard".

One other "nuclear option" type thought. I once had a cam that was ground 9 degrees off (advanced). That caused tremendous KR issues that weren't possible to tune out completely. Have you considered verifying your cam is properly degreed in?

RonSSNova

iTrader: (3)

He didn't change the timing
Needs both tables changed.

ddnspider

iTrader: (26)

The other thing I would do is change the knock decay rate. Stock decay rates are ridiculously long that you cant correspond to what timing cell or rpm knock is actually occurring at. I usually set my stuff to .25 so as soon as knock stops, it doesn't pull timing any longer.

RonSSNova

iTrader: (3)

Agree

Also just read that if you download the latest 3.0.18 as of today, you will get double the data speed. :-)

Darth_V8r

iTrader: (4)

TR55 is the stock standard, but for a cammed car with higher cylinder pressures vs stock, even a mild build, a colder plug is beneficial. That's why I suggested TR6

2MCHPWR

iTrader: (10)

hi - i have the stock 98 tune from hp repository in front of me and it is the same exact values are what mine is. The one you posted on the bottom looks closer to the z06 stock tune i have. Are you sayinng to paste the z06 numbers in my table? I wonder why the z06 has high levels there (more aggressive cam? ..550 lift in 2004 z06).

mine which is same as stock 98 camaro i'm looking at:

6 5 6 6 6 5 7 6 7 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 9 9 8 9 8 8 8 9 8 8 8 8 8 8 8 8 8
8 4 5 8 7 8 7 7 6 7 7 8 7 7 8 8 8 8 8 8 8
7 4 5 7 7 6 7 8 7 7 6 6 7 7 8 8 8 8 8 8 8
6 4 5 6 6 8 7 6 6 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 8 6 7 7 8 6 7 7 7 7 8 8 8 8 8 8 8
8 5 5 8 7 7 7 6 7 6 6 7 7 8 8 8 8 8 8 8 8
9 4 5 9 7 6 7 8 8 6 7 7 7 7 8 8 8 8 8 8 8

and here is the stock 2004 z06:

11 11 11 11 11 11 11 11 11 10 10 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11
11 11 11 11 11 11 11 11 10 10 9 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 10 10 9 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 10 10 10 10 10 10 10 10 10 10 10 10 10
11 11 11 11 11 11 11 11 10 10 10 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 10 10 10 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 11 10 11 9 9 9 9 9 9 9 9 9 9

2MCHPWR

iTrader: (10)

do you mean .25 or .025? because the stock values are closer to .025 range. See below stock tables, mine are same as stock:

0.010009765625 0.010009765625 0.012451171875 0.012451171875 0.014892578125 0.014892578125 0.015625 0.015625 0.015625 0.015625 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125

changing to .025 is doubling the value but .25 would be way too high. right?

Darth_V8r

iTrader: (4)

Won't quote good on my phone. Those I posted are the stock 1999 values. If still say give it a shot. Cammed cars naturally make more noise and tend to need KS a bit less sensitive

2MCHPWR

iTrader: (10)

hi - i made some changes tonight. Log files are short because its friggin snowing but i'm still getting kr. Went back to the original tune and made these changes:
-lowered KR sensitivity by inputing a higher numerical value – copied from 2004 z06 (spark – knock sensors – RPM vs Cyl)
-changed PE back to stock

There is no oil in my catch can.
I still want to change my plugs (TR55 on shelf).
I will check the rattling but I really don't think that is it.

Max value of the KR in the log is less than last night. Keep in mind last nights changes to the tune were made it richer (high 11's), and low octane table was higher than the high octane table. I reversed both of those and just started with the base tune since those changes did nothing. Tonights a/f was mid 12's.

does the jagged STFT and LTFT have any significance?

joecar

There is a known problem with 1998 knock senors reporting a constant 4* KR... the GM Tech Bulletin says to replace both KS's and the subharness and quotes GM part numbers.

If you think this applies to your situation, check what KS's and subharness you have (are they GM or ACDelco).

ddnspider

iTrader: (26)

.25. It is knock decay rate. If you read the table description (at least in EFI Live) it specifically tells you that this table is for when knock has STOPPED. You don't want it pulling timing after the knock has stopped. I have a buddy who has the same issue that Joecar describes below on his 98 TA where it will always pull 4 degrees of timing at WOT.

RonSSNova

iTrader: (3)

So it sounds like new knock sensors are in order.

2MCHPWR

iTrader: (10)

already done:

joecar

Only GM/ACDelco KS's will work properly.

RonSSNova

iTrader: (3)

I've heard this as well.
Also should prob torque them properly......

gagliano7

I heard if you over torque them they might not work so torque to proper specs. I think i was next to you during the fall by the healey chevy in Middletown. Your car sounds good.