Question about trim and housings

[Actual_Ben_Taylor]

Right, so I understand that trim is to do with the relationship between the size of the inducer and exducer of the wheel, but if you change the trim of the compressor wheel do you also need to alter the compressor housing to match? Or does the compressor housing just have to match the size of the exducer?

Cheers :)

[TurboDynamics]

Hi Ben,

You are correct in that trim is the relationship between the inducer and exducer of the compressor wheel. You can compare different trim sizes of the same exducer, you cannot compare trim sizes of different exducers as both the inducer and exducer will be different.

The profile of the compressor housing is carefully matched to the shape of the compressor wheel and is machined to a clearance tolerance. Anytime you change a size on the wheel (inducer or exducer) the profile will become wrong - it may become "gappy" if the inducer shrinks or it may "rub" if inducer grows. In a similar fashion changing the exducer will alter the shape of the profile (and may even have a different tip height further complicating things).

I don't fully understand what you are asking as the exducer of the compressor wheel sits in a recess in the bearing housing not in the compressor cover. I suppose in simple terms the answer is yes you would have to modify the compressor cover profile if you changed the trim size.

i hope this helps and makes sense...

Matt

[Actual_Ben_Taylor]

Makes sense, thanks for taking the time to answer :)