Turbine sizing -- how small is too small?
Thread Starter
Staging Lane
Joined: Sep 2004
Posts: 73
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Turbine sizing -- how small is too small? I feel like I may be overlooking something completely obvious, but I'm trying to figure out what the downfall of having a small turbine side is. My first thought is that it will create too much backpressure in the exhaust, but with a very large wastegate (or two), couldn't backpressure be controlled? The turbine works based on the pressure difference from the turbine entry to exit, but I don't think that a smaller turbine requires a larger pressure differential. If anything, I would think it would be smaller. With an adequately sized wastegate, couldn't you theoretically release enough exhaust to keep the exhaust pressure as low with a small turbine as you could with a large one?
What am I missing? Is the mass of the compressor wheel so much that sizing the turbine differently wouldn't help significantly? Would balancing become such a large issue that this isn't a possibility? I'm guessing that I'm overlooking something simple, or else there would be more people with T3/T88 hybrids and incredibly large wastegates. It seems that the best approach to choosing a turbocharger would be to size the compressor accordingly, then to use the smallest turbine possible and the largest wastegate.
Where is the error in my train of thought? Although I really hope that I'm not mistaken, i'm pretty sure I must be because nobody seems to do this -- thanks!
What am I missing? Is the mass of the compressor wheel so much that sizing the turbine differently wouldn't help significantly? Would balancing become such a large issue that this isn't a possibility? I'm guessing that I'm overlooking something simple, or else there would be more people with T3/T88 hybrids and incredibly large wastegates. It seems that the best approach to choosing a turbocharger would be to size the compressor accordingly, then to use the smallest turbine possible and the largest wastegate.
Where is the error in my train of thought? Although I really hope that I'm not mistaken, i'm pretty sure I must be because nobody seems to do this -- thanks!
