No. You have assumed that ignition occurs at TDC. It occurs at a certain number of degrees before TDC. The amount varies based on the engine and it's tune.

To truely describe what happens would require a full lesson. Much more then I can describe here in a thread post. There is a lot of physics going on there with a number of inter-related things happening at once. Everything from the octane in the gas to the volumetric effeciency of the combustion chamber. But, the goal of it all is the same...

The idea is to ignite the fuel at such a time where the flame front from the spark plug will impact the top of the piston right at the moment that it begins to move down on the power / combustion stroke. In order to do that, you have to light the spark several degrees before TDC to give the flame front time to move from the plug to the piston. Some engines ignition timing is as much as 70 degrees before TDC.

 

i dont know not one of them damn answers halfcent and i can still figure out hptuners :P

 

That's because you have god-like powers beyond the normal man, Eddie.

 

What Halfcent is saying is that just don't expect to get the program and install it and then viola instant results. I've been practicing with HPTuners for over 6 months now fairly frequently and it still amazes me with all the parameters that can be changed.

For instance, I just learned when and where timing needs to be added in relation to a dyno graphs output. The numbers derrived from the graph point you in the right direction, however you need to know what rpms and what airmass (g/cyl) you need to make the corrections at. I also just learned a few things about how methanol will affect your a/f ratios and how you can get your nice a/f ratios back that you had without it by adjusting timing or the PE tables. My local tuner is a wealth of information and just spending 4 hours with him a couple saturdays ago exponentially increased my knowledge about tuning.