"C" turbo specs?

i have experience and knowledge in turbocharged diesel engines, but am new to the MV world. my question is what is it about the C turbo that makes it whistle the way it does? also does anyone know the specs on them? such as compressor/turbine wheel size, exhaust housing size, mounting flange style etc... i am just curious (and yes want one on my next diesel project ) thanks in advance

The pitch/size of the blades.

thats what i figured. i want to get my hands on one/take one apart to get an idea of the specs

the exhaust housing of the C turbo is smaller than the D turbo... but what frodo says might have something to do with it...

these threads should give some help

http://www.steelsoldiers.com/deuce/16562-turbo-classification.html
http://www.steelsoldiers.com/deuce/24726-whistler-turbo-vs-non-whistler-turbo.html

awesome thanks! well there goes the rest of the afternoon of productive work! ha ha