Charlyne 95 Z28 M6

[meissen]

I tried taking a stock tune and adjusting the injector flow rate to my higher lb injectors, etc just to play with tuning and what not... Stock spark advance numbers were giving me knock, I noticed that right away. Looking at the Stock 95 Z28 (A4) tune I have, I'm seeing spark advance at 27 in the 800/25 cell where my tune has 21... seems too high compared to mine.

The reason why I was curious is I was reading the lt1tuning.com or whatever Tuning Tips and they say to increase spark advance at idle until you see knock, but in my case I see knock with the stock spark advance.

[Boost Addict]

Do you have an LT4 km?

[Fox Slaughter]

Nope. I haven't tried tuning the KS yet either which you can do.

My idle is set at 34* and no knock.

Did you change it on the Main Advance Table or Closed TPS Timing table?

[meissen]

Mine idles around 20 give or take a couple degrees. I'm not sure exactly where it's tuned, I thought it was just the Main Spark Advance vs RPM vs MAP

[Fox Slaughter]

Nope its tuned under Closed TPS Spark Advance Vs RPM.

closedtps.jpg

I hope you don't mind. I copied your Spark tables and she responds much better but she still is picking up some knock in some spots. Highest was 5.5 at 1600rpm 95.2KPA.

I just ordered a LT4 KM. Just to see if it works.

[meissen]

Technically it should be - "I hope Steve from SB Tuning doesn't mind" since it's his tune. You have a cam don't you? If so, yeah that LT4 KM is a must.

[Fox Slaughter]

No cam sir. Not yet anyways. So least I will be ahead for when I get a cam.

Hey I didn't copy the whole tune, just the spark portion of it. Haha everything else is my own settings.

[Fox Slaughter]

Well put the LT4 module in and still seeing spark knock. Now that I think about it I don't think I had retard from before I redid the heads. So the question is would bad valve lash cause spark retard? Like the PCM is picking up the noise and thinking its a knock and retarding the timing?

[meissen]

Could be - but the factors that go into when the PCM detects knock and retards the timing is a complete mystery to me other than I've always heard it's pretty inaccurate.

[Fox Slaughter]

Well its funny because its pulling timing but very rarely is the knock count going up.

What is your Burst Knock table set to? I zeroed mine out.

[meissen]

mine's stock

[Fox Slaughter]

Nevermind those are the plugs for my Saturn. I am running TR55.

I wonder if the knock sensor is on its way out and its just acting weird.

[JoeliusZ28]

I need to work on setting my laptop up so i can participate in this convo.

[Fox Slaughter]

I need to work on setting my laptop up so i can participate in this convo.

Get your ass in this convo and help out!!!

Well I am glad I pulled the valve covers off. I found a piece of cardboard that goes on the end of a spark plug down between the push rods on cylinder number one sitting on the intake gasket. Jeez I can't believe I some how got that down there.

Flashed a new tune lowering the VE tables. As the engine was cooler it seemed the spark knock wasn't there but as it went up in temp the more knock popped up.

[Fox Slaughter]

It seems like everywhere I am getting knock its because of the "Mystery Timing" the PCM adds itself. Everywhere I have knock its higher than what I am calling for in the Timing Tables. I read before the PCM will add its own timing where it thinks its necessary and no one knows why.

Also Brian looking at a datalog you put up of your car I saw as high as 7* of spark retard.