I was looking over a tune supposedly written by a professional programmer that we all know.

It appears that the main spark table has been dramatically increased in the lower rpm and high map region of the table.
However in the high rpm/ high map region of the table it is only an increase of 2 degrees or so.

My question is: is it possible that the stock tune being set at 10 degrees of timing at 95 and 100 kpa at approx. my launch rpm could be causing the Knock retard that I get.

And for that matter could my timing being 2 degrees lower in the high rpm/high map region cause some KR to develope.

Still in the never ending search for knowledge.....I'll probably be there for a while...

 

No. Don't know exactly what is going on other then its dropped because of open loop at wot (can not tell exactly how lean it is) and the more air that goes in (higher map) the more likely it is to have predetonation.

Hal

 

Weak timing would cause weak power, if it says only 10º at high MAP low RPM I'm going to guess this is a stroker on pump gas type tune?

I had to increase timing a good bit at lower MAP low RPM, but getting into the 85+ MAP low RPM range, I had to be carefull otherwise I would ping. Thankfully though you shouldn't really see high MAP like that unless your bogging the car down badly, fixing the timing can improve your MAP as well, of course. As best I can recall my heads/cam car saw a best of maybe 35 MAP cruising on the freeway.

 

Oh now I read your question a little closer. If I remember correctly there are other tables that can add in timing. I believe they are just trying to confuse the matter by using those.

Hal