My opinion is a S5 hybrid is a better alternative to non-sequential twins if you do not have to pass a visual smog inspection and have a little to spend on a turbo, but not a lot to spend.

More simple and less lag than non-sequential twins.

More lag than sequential twins though, so if those are working...keep them.

Opinion based on owning a 380rwhp S5 hyrbid FC RX-7 and stock sequential FD RX-7.

 

im thinking about doing this also to my new FD. the clearance between the compressor and a TII LIM is next to nothing on most hybrids, so on a FC, a T04B sized compressor is the limit.

But looking at the pics posted, it looks like you could go with a bigger compressor on an FD engine.. has anybody tried this? I think i have an extra T04S cover (4" inlet, 2.5" outlet) i can bolt up to my 60-1 hybrid, i will try it when i get the chance and post it up if anybody is interested

 

do you think bigger = better though compared to the T04B? I don't know personally but I guess you could give it a shot

 

It is a T04B HiFi used on FC which flows 10% less than the full size T04B compressor housing.

Yes, the full size T04B compressor housing fits on an FD or Cosmo motor and BNR has done this (dynoed over 400RWHP).