Initial timing is 7 . After 1500 Rpm car runs awesome but from 800 to 1500 she loss power , no quick acceleration , also cant do a burnout (posi, rear disk brakes)what timing must be on vortec GMPP heads in range of 800-1500-2000 rpm, BLMs seems to be good around 130-132 . 6965 ECM heres some tables that i try on last few days. http://img12.imageshack.us/gal.php?g=vortec3.jpg

 

Maby this table will be better ????, uf vortec dont like big timing then why a stock vortec table that Rbob posted have 45-34 degrees at WOT ib 40-100 KPa . what table is really for vortec ?

 

I think it may have been Fast355 that posted the Vortec table info. However, 40 Kpa is not WOT. The WOT timing is in the 90 to 100 KPa range.

40 KPa being light cruise an engine can use more spark timing. This is because the density of the air/fuel mix in the chamber is much lower. And takes longer to burn.

This thread has some Vortec engine SA tables:

https://www.thirdgen.org/forums/diy-...ark-table.html

With the last post having a link to a thread that shows RamJet SA tables. The RamJet engine used Vortec heads.

RBob.

 

Also is there some free software that can show actual realtime timing ?

 

You would need to patch the ALDL stream with the SA location. Then do some math on the value at the scan tool. In the "Come in for a free tune" thread it is explained. However, the lcoations are only there for the '7747 and '8746 ECMs.

RBob.

 

maby someone have similar engine and can show his SA table ?