first of how do you read a compressor map. then how do you pick a turbo. how are they rated. and how do you tell how big it is and its characteristics from its name.
thanks guys and happy holidays

 

Best bet is to buy a couple of books, one is Turbochargers by Hugh MacInnes and the second is Maximum Boost by Corky Bell..

Or, just find a setup that you like that worked for someone else and mimic that.. There are lots of proven setups out there and all the leg work has been done.. Just buy similar parts and you should be able to experience similar results..

Cheers,

 

first, you have to find your pressure ratio, then find airflow rate, then multiply your pressure ratio by your basic CFM (airflow rate), and that's your flow rate under boost. Then plot your pressure ratio and boosted flow rate on the compressor map, which will give you the max flow the compressor can produce at your pressure ratio, and what efficiency percent it will be at that flow. Surge characteristics should be considered also. to do this, plot a point with your pressure ratio and cfm proportional to the rpm at which the desired pressure ratio is reached, and another at a pressure ratio of 1.0 and cfm at 20% of max. draw a line between the last two, and as long as the line stays to the right of the surge limit line, it's okay. But in order to find all these numbers, you'd be better off to buy a good turbo book.

 

Almost, but when comparing air flow you need to first convert the pressure ratio to a density ratio by approximating the compressor and intercooler efficiency at that point.

 

my bad, you're right