[Vwdiesel] turbo boost & compression ratios

[Roger Brown]

Harmon Seaver wrote:
> 
>    Does anyone know of a formula for figuring out how much a turbo raises
> compression ratios?

Compression ratio of the engine doesn't change when adding a turbo.  You are changing the pressure (or density or amount) of the intake air by the amount of boost that the turbo gives.  That increased pressure is essentially magnified by the existing
compression ratio to give you a higher combustion pressure.  Here's a few interesting pages from a Google search of the subject:
	http://www.teknett.com/pwp/drmayf/comprato.htm
	http://www.smokemup.com/auto_math/pressure_ratio.php

-- 
   Roger