Does anyone know of an equation to predict compression rations at certain boost settings? ie with initial CR of 9:1 with oh 17psi....im sure somehow the bore and stroke come into play...any ideas?

 

Man anytime i post a pic of my car or something i get a million and one dumb comments, but when its a logical question...noone has anything h-t

 

It's not a very help full number.Relating boost pressure to compression ratio is apples and oranges.PSI of boost is backpressure in the manifold not pressure in the combustion chamber.Cylinder pressure is the real psi number of importance.

 

I think he is referring to changes in effective compression.

 

I believe its like 20-1. Ask a machine shop. there is a chart with motor size and boost that give the compression.

 

dont really have any shops to ask. There should be some sort of equation relating the chamber size, original cr, and stroke....i just haven't got a clue how to compile an equation.... :-/
And yeah im going for effective CR...for fuel calculations.