ive learned that 11.5 cr is the most you want to go on a street car and pump 91 cali octane. But is this for static compression or dynamic compression?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondaIntegraR &raquo;</TD></TR><TR><TD CLASS="quote">ive learned that 11.5 cr is the most you want to go on a street car and pump 91 cali octane. But is this for static compression or dynamic compression?</TD></TR></TABLE>

Static. Static compression is basically what you have withot calculating the cam lift/duration. If you start to bring in cam lift/duration then you will have dynamic compression. Hence why large cams recommend increasing static compression beyond a certain point... because the dynamic compression is going to be much lower.

 

so if my current compression is 11.5 and my cams bring it down to 10:1, i should have gotten pistons which yielded 13:3 in the first place?

 

usually when people say they have a 12:1 comp or what ever ration they are refering to the static ratio... i would say that 63% of people dont even know that dynamic and static compression have anything to do with VE

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1SlowB16EF &raquo;</TD></TR><TR><TD CLASS="quote">usually when people say they have a 12:1 comp or what ever ration they are refering to the static ratio... i would say that 63% of people dont even know that dynamic and static compression have anything to do with VE</TD></TR></TABLE>




Pretty much!

 

Of course if you can figure out ways to greatly increase the intake air velocity over stock, then it will increase the dynamic compression without having to touch the static compression. Then the issue becomes cams as too small a cam won't allow enough of the air in, thus lowering dynamic compression to less than it would have been with the stock setup. Lot of fluid dynamics theory in this, I'll spare the details.