Is there a ratio between the two that works best?

Good question , would'nt this be the 'holy grail'? , am i right in thinking the calculators for determining DC are hit & miss? , the way i see it static CR is meaningless , it all hinges on IVC , so are we looking for a specific DCR across the board regardless of SCR?

Well I waited till the weekend to throw this one up here, I know its a very general question to a very involved process but there are a lot of swift guys on here that have have probably plowed thru the math and have come up with some base line results, A lot of it is trial and error or field test results but some one must have come up with sort of a rule of thumb that has value

Trial and error is right. Just think of all the variables that effect the amount of air coming into the cylinder before that intake valve touches the seat.Carb.size plenum volume,runner distribution variance,runner entry shape,taper&size,valve size,lift rate,seat angles,port shape& flow,chamber shape,valve shrouding, piston acceleration rate&velocity,brand of beer consumed while assembling the engine,etc.etc. It boggles the mind.

I see your point, I was leaning more toward fuel requirement at the inception of a build with a some what general VE target

This one has been pretty close from my experiences
http://www.rbracing-rsr.com/comprAdvHD.htm
I think many engine builders aim at 185 max with aluminum heads for 93 octane? I ran my old motor at 195 (193 to 202) on sunoco 94??
Iron heads maybe 160 and attention to any sharp high spots that can glow is a must!
Tryng to get this JWD closer to 190 I'm at 160 low now and 170 high was at 150 low and 160 high so advanced the cam 4 more degs??

Is there a chart or calc for dynamic ratio and fuel requirement?

There must be somewhere as depending on how brave you are 200 with aluminum heads seems to be the upper limit with pump gas but most seem to say 180 to 185 with pump gas and aluminum heads.
You TQ is also a factor as the higher the RPMs the less octane needed as air fuel mixture burns at a constant rate and things happen quicker at rpm.
So as an example a car with a 2500 stall loads at 2500 and may ping till 4500. put a 5000 stall in the same combo and it loads at 5000 beyond the detination as the piston gets over the top much quicker before air/fuel can expand enough to detonate/ pre ignight~!!!

KB calculator similar results on the dynamic compression but not exactly the same heard this is most acurate
http://www.kb-silvolite.com/calc.php?action=comp

Found this number
DCR of 7.8:1 - 8.5:1 for pump gas with aluminum heads
think it said 7.5 to 8.0 for iron heads?

Correct , it seems everyone's looking at static compression for fuel requirement when most race engines dont operate at low rpm, I make 220 psi static with 12 to 1 and according to the calcs I range between 9.8 and 10.2 DCR , the engine load starts at 5k to 7k , I am more interested in fuel requirement using DCR , it seems that could be done on a chart?

I searched and could not find one??

This is around the point where the swift guys are suppose to help out

Good question, in theory the intake valve has to be closed, so the on line calcs vary , but what about valve lash, lobe ramps, solid compared to hyd cams it all effects DCR by exactly when the intake seals the chamber

They vary slightly but it is a good general guide. tight lash compression goes down loose it goes up ever so slightly!!

I used some online calcs using a known combo for giggles. If I use the instructions my DCR is 9.44,when I sustitute the the more accurate closing point I get 9.14 DCR. I don't spend much time playing with DCR calcs,I haven't found any magic in them.

in theory the intake valve has to be closed

Actually, the stoppage can be from the closed valve, or simply the difference in pressure between the inertia of the intake flow vs. the lower static pressure of the charge in the cylinder ATDC.
At low speeds, there isn't enough inertia to get flow to enter after the piston changes direction, and flow not only stops at the valve but reverses.
At higher speed, inertia keeps it going until IVC.

DCR is useful to estimate how knock-prone an engine will be a low to mid speeds, but (as said above) at high RPM the full stroke length is captured and compressed (not just the stroke after IVC) at the beginning of the torque range and DCR becomes irrelevant.

So if your stall is below peek torque the DCR numbers will help at lower rpm & if your stall is high in the rpm range DCR is not too inportant , ok I was just trying to figure a better way of setting total advance with different fuels without pulling the plugs and looking all the time, a chart would be nice but I now see