[sleepydsm]

Ahh, thanks, that does help. I did have a basic understanding about the exhaust A/Rs, but how do the compressor A/Rs affect things? I thought the more important number on the compressor side is the diamater of the wheel ( i forgot if it was inducer or exducer) and for some reason it seems the diameter of the wheel has some relation to how much air (in lbs/min) a turbo can flow. (ie a 100mm wheel can flow about 100 lbs/min). Please set me straight if I'm wrong!