got extended spark adv v.s rpm v.s map , set @ 34degrees 4000 and up to 6000 , 6000 and up 33.5,(@100kpa) when I datalogged I see 36/37/38 degrees ,at 100 kpa, where did the xtra timing come from?and how can I adj it?

 

might be from the spark correction vs coolant temp.

 

spark correction v.s coolant ? I don't see that on there, mabey it is named something else?

 

spark correction vs MAP vs coolant temp to be exact. its right near the main and extended spark advance.

 

If you truly find where that additional timing is coming from make sure and post. I have not heard of anyone knowing the origins of it.

Ben

 

for giggles......I changes a few values(by very little based on values I found someone else's PCM) in the MAF calibration tables..... diacom showed timing went completely bug nuts. I don't pretend to know the exact relation of one change and it's perceived amount of affect on the other paramenters....but I'd say it's got a great deal to do with it. I'd imagine even minor changes to the airflow (pre, post and IN the MAF) could make significant differences. If the MAF wasn't the key (non-speed density) then the MAF translator and the plus model wouldn't have the affect it does.

 

Doug,

Explain what you mean by this? I looked at some of my old files before and after I calibrated my MAF and I see no difference in added timing. Where I looked on my data, I had modified my MAF by about 5%.

Interesting you should note this as one other person has ever indicated a relationship between MAF and timing.

Ben

 

when I get time to wade through the mass of diacom .gdfs on the hard drive....I'll make available what I saw. I made changes of more than 5% and it's wasn't linear from cell to cell. I wanted to see what individual cell changes would do (since I have little good info on it and had almost zero on it at the time). the car ran sick....at certain spots for the 30 minutes the program was there.....

 

Explain how the maf tables affect timing?

I would imagine that the timing you're seeing is hardcoded somewhere in the ECM. Remember, the tables we can edit with TunerCat and LT1Edit aren't the only tables that the computer uses.
Just learn to tune around the timing.
I've posted a couple of times at what rpm the computer adds timing and how much...but can't remember off the top of my head.
I think it's 2 degrees until 4000rpm, then at 4500 and 5000rpm it adds 3 degrees, then at 5500 and up it adds 4 degrees.

 

Think, man, think!!!!!!

Try and find that post, I would like to know.

 

The pressure is too much....can't....hurting....

No...it's as I posted above.
I'll e-mail you a file and if you look in it you'll see the timing drop from 90-100map and where it occurs. This is exactly where the ECM adds its mystery timing. The file I'm sending you is set up for 34* too.