3800 Ignition Timing

[GMcarguy]

On a 2000 Grand Prix GTP, can anyone tell me if the ignition timing is retarded at WOT. Sometimes when I am running through the gears it feels like it softens power at the top of a shift. When I go a little less than to the floor, 90% throttle, it seems to shift alot harder. The only reason I can think that it would do that is to soften the blows on the transmission for longer life. Will this be eliminated with an aftermarket PCM (DHP)? I have encountered a similar experience in a 2000 Trans Am.

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[gtphale]

At the top of your shifts you are probably seeing knock. If that is the case then yea you will lose some timing. Therefore causing the lost of power. Proper tuning and mods will fix that problem

 

[imported_Ron Vogel]

Also to add to Hale's point, your car will learn to keep ign timing below the point where kr starts.

 

[BlkJak]

My worst spot for KR is when it shifts into 4th. And it's awful. I have the 104's, but I guess thats what I get for getting a GT. Looks good otherwise.

 

[gtphale]

isn't 104's for a gt a little to cold? Not sure cause I've never modded a gt before or read about them at all.

 

[BlkJak]

Seems to be running fine. Haven't had any trouble... yet. :huh:


At least I hope it's not bad!!!! :huh:

 

[sr71_rgl]

I recently read somewhere that there's a "low octane" fuel table the PCM can read from that has lower timing values in it. Any truth to this and if so how can we stop it?

 

[LP 3800]

Do what I did and just visit charles for a day in the garage and get a happy knob. That way you can crank the timing all you want
P.S. not a good idea

 

[imported_Diavolo]

LP haha :lol:

 

[sweetness]

A tthe shift point the computer pulls out some power (whether through timing or what i don't know) to lessen the blow on the tranny. DHP will rid you of that problem.

BC

 

[sr71_rgl]

Originally posted by LP 3800@Feb 10 2004, 06:21 AM
Do what I did and just visit charles for a day in the garage and get a happy knob. That way you can crank the timing all you want
P.S. not a good idea

I did just that last fall and still see timing values of 12/13* at WOT when the knob is set to 0. When I'm +2 i get 15/16* and +4 gives me 18/19*. Something's not right here....