25-09-2012, 01:57 PM
Boost does equal flow... It's efficiency that affects things...
When you're spinning a baby little t2 to make 30psi with 28lb/min, you might have a chance of moving that air, but then you consider that the shaft speed would be something like 350,000 you've maybe got 30% efficiency... It's predicted compressor outlet temperature is probably close to 300*c... So in actuality because the air is so thin on the output, you'd only receive quarter of that due to the heat... Then after intercooling you might regain a little, if you're lucky up to a half...
You need to understand the relationship between boost, flow and shaft speed... The higher the shaft speed, the higher the heat, the more work the turbo does, the less efficient... However drop the shaft speed too low, you'll run into surge... Push the other way, you're into choke... It's all a fine balance... But it all boils down to efficiency. If you're in the turbos peak efficiency island, you don't have to do much intercooling, its an easy life, and gt2052s and 2056s are slap in the middle at about !60-180hp
When you're spinning a baby little t2 to make 30psi with 28lb/min, you might have a chance of moving that air, but then you consider that the shaft speed would be something like 350,000 you've maybe got 30% efficiency... It's predicted compressor outlet temperature is probably close to 300*c... So in actuality because the air is so thin on the output, you'd only receive quarter of that due to the heat... Then after intercooling you might regain a little, if you're lucky up to a half...
You need to understand the relationship between boost, flow and shaft speed... The higher the shaft speed, the higher the heat, the more work the turbo does, the less efficient... However drop the shaft speed too low, you'll run into surge... Push the other way, you're into choke... It's all a fine balance... But it all boils down to efficiency. If you're in the turbos peak efficiency island, you don't have to do much intercooling, its an easy life, and gt2052s and 2056s are slap in the middle at about !60-180hp
