this might sound kinda dumb (dont flame me
) but every1 keeps talking about getting this tune or getting that tune but dosent the cars stock computer tune the car automaticaly to best suit econommy/performance? so when everyone says get a tune ect are they talking about ripping out the stock computer and replaceing it with a custom computer that can be manualy programed? or is it just useing the stock computer with a moddified performance chip put into the computer some how? (can see i wasnt paying attention in computer class:unsure:lol)
in most cases, no. the best way to tune our commodores is with a software called kalmaker, which allows real time dyno tuning of the factory delco pcm (ecu, whatever you would like to call it - the brains of the engine and transmission).
with kalmaker you can change hundreds of the parameters in the pcm and retain a factory "smoothness" which is usually lost when using piggyback or replacement ecu's....plus the delco itself is a great unit, much better than all but the very very expensive aftermarket items.
i think you may be a little confused about how the delco works to self correct itself. it does not automatically adjust itself in a manner like having the engine tuned does. it can make small corrections, but is always limited by the factory set guidelines/specifications in the factory tune.
so, it can pick up a signal from the oxygen sensors that its running lean and needs more fuel and simple things like that - which is how it makes itself run economically.
but when it comes to something like changing the cam, which as i said before changes the whole characteristics of the engine and its power delivery the pcm cannot adjust far enough out of its parameters to suit, plus there is a considerable amount of things that must be changed, like timing for instance, which the pcm cannot change itself.
to answer john's question, you WILL need a tune to suit with a cam change (as you would note from my explanation above). a cam grind can be as cheap as a couple of hundred dollars, thats why i think its so humerous that companies ask so much ($1k+) for a cam and chip package, when you could get a custom cam grind and a kalmaker tune for about the same money and have MUCH better results. :thumbsup:
