First is the power rating. It depends usually on the inducer size, mostly. Inducer size is the inlet hole into a turbo, which sucks the air in. It also refers to the smaller portion of the compressor, in front. Major is the overall size of the compressor/exhaust wheel. Look up on the dissected pics to see what I'm talking about. Housing is the cover/chamber where air is pressurized/flows, does not affect power ratings on the compressor size. Trim is the ratio of inducer
verall compressor wheel. It also affects power, for ex: t3/to4e 46vs 50vs57vs60 trim. The power ranges from 400to500 whp in that order. Honda people like 57 for some reason. Also t3 or t4 housings affect spool up of the turbo. Generally t3 will spool up quickly but will not be as impressive on the top end, depending on app. and engine size. A/R of turbo is also responsible top end/spool tradeoff. Usually companies calculate hp powetial of a turbo by multiplying its maximum flow in lb/min by 10. It is approximate and will depend on your setup. It also means that no matter how hard and how many psi you will push, your setup is going to be limited by compessor flow. Pro racing does this by limiting inducer size on the turbo, like in WRC. So, a v8 car running the same turbo is gonna produce about same hp as 4cyl with the same turbo, when pushed to the max, but with less psi and probably more tq. But with lager displacement you can utilize bigger exhaust housing A/R and wheel, making it more efficient.
What is your setup? Type of engine, displacemet, max rpm, maximum desired hp, response vs top end power required? How built up your engine is gonna be? Those are teh factors that decide turbo size.
Linear Mode
