The Nene had a single stage compressor with double sided impeller.subcritical71 wrote: ↑Tue Oct 30, 2018 3:36 pmGood points hurril. I still struggle (for myself) in this case of the nene 10. I could go either way honestly. And if it would be considered a single stage could you then modify one half of the 'stage' so that the pumping characteristics can be shifted slightly to give a better overall operation of the turbo? That would be really interesting.
The Rolls-Royce R also had a single stage compressor with double sided impeller, as did the early Sabre versions.
The trick with the F1 regulations is that not only do they ban 2 stage supercharging, they also limit the turbo to one turbine wheel and one compressor wheel.
For mine, the double sided compressor would be OK so long as the impeller was one piece. If you had two pieces mounted back to back its legality would be questionable.
The double sided compressor may become more attractive if the 2021 rules move ahead with the elimination of the MGUH. For while the current rules favour large compressors (I am guessing they are more efficient), the lower inertia of a smaller, double sided, impeller would improve spool up/reduce lag.