87/77.5 turbine wheel?

[jeff115]

I never see any one talk about these. How do they compare to the 87/80?

 

[Smokem]

78/87mm is non-clipped whereas the 80/87mm is cast-clipped, the smaller wheel will flow less and spool faster.

 

[Str8jacket]

78/87mm is non-clipped whereas the 80/87mm is cast-clipped, the smaller wheel will flow less and spool faster.

Sorry, do you mean the wheel with the smaller exducer will flow less and spool faster?

 

[Smokem]

Yes.

 

[Str8jacket]

Cheers Smokem. Another question. Given 2 turbines with the same size exducer what are the effects of a larger overall diameter compared to a smaller "clipped" one? Im assuming the larger will spool slower. Would the larger diameter flow more due to the extra area exposed to the volute of the housing? Or is the overall governing factor the exducer size, you would think all things else the same it would be able to push a larger comp wheel or utilize a smaller a/r housing if the volute theory is valid.....or am I paying to much attention to the voices in my head?

 

[Ghostman]

I'm not an expert by any means, but the way I see it is the exducer has more to do with "flow" because it is the last restriction in the turbine stream and is the smallest and the inducer has more to do with "turbine HP" since a larger wheel will generate more leverage, and both need to be sized accordingly.