ok, im looking at two differant turbos, one being shall we say - large turbo escort - T34 - compressor A/R 0.60, i then look at another T3 variant but this time with a MUCH larger looking compressor with an A/R of 0.50 - so what is this all about then >? this is obviously a larger volume compressor but where and what meaning does the A/R figure have ?

please enlighten me -