Cadillac Powertrain Control Module (PCM) Tuning Discussion, LT1 B/D PCM tune vs LT1 F/Y Tune in Cadillac Engine Discussion; Something I have noticed, all the B/D cars have a 20 degree offset on the timing table, and the F/Y ...
Something I have noticed, all the B/D cars have a 20 degree offset on the timing table, and the F/Y cars don't.
I think I found out why.
The Timing tables can go from 0 to 110 degrees. But there are some places in the timing table that GM goes negative in the B/D tune at a couple places in the timing table. The F/Y tune does not go negative.
I guess what I meant is why would a car go below zero in timing, moreover, is it good?? Must be since my car still runs good! I just don;t have the slightest clue what a timing table is. My old pickup I know you have initial and total timing, that I understand. Is this the same?
They have it set to do it in odd conditions like super low vacuum and low rpm. Like engine start. If you get very high at that condition you can get starting pinging.
My 454 sees 0 degrees timing factory at high load conditions. Even negative timing. There is initial timing in the PCM tune, but it is the closed throttle timing now, and the timing maps handle it all now. There isn't "advance" like in a distributor anymore...