7AGZE Ideas

[Duk]

Cheers for joining in and sharing your set up and ideas, Nick!
The best thing about the twin screws is their ability to deliver higher boost pressures than the roots SC's, that are still within the efficient areas of their compressor maps.
I have been keeping an eye out for ex-Mercedes M62s, partly because an M62 would be an ideal size and because the Merc M62's used a clutch and I believe they used a blow thru TB set up. I've got nothing against draw thru TB, but the pure plumbing volume between the TB and the inlet manifold causes the typical 'difficult idle speed' problems that the GZE donks suffer from and I'd had enough of that before my SC12 died, so I'm keen to do a different job next time.

[maj]

Personally I think if you are building anything more than a worked 4A, you should ditch an SC1* for something better.

Eaton TVS/Harrop is the ideal SC I think, keeps with the roots SC principle but modernised, so less shortcomings that would steer you towards twinscrew.

[AE25]

Noise is a known problem without the throttle upstream which acts as a baffle plate. Could possibly do a double throttle layout.. just make sure the upstream one flows more or opens earlier so to maintain control from the main throttle. The supercharged Estima van even has an expansion chamber on the sc14 outlet pipe.
I remember an article on a supercharged prius on autospeed. The end result was the induction howls were not bearable.
oh found it.. http://www.autospeed.com/cms/article.html?&A=112194

there's more room under the 20v inlet with the vacuum hoses moved, than an oem 16v inlet.

Im sure you know that a bypass valve is mandatory with throttle after roots SC. The poppet or butterfly style valves work better from being progressive rather than the instant release from a piston type bov.
The merc M62 uses a butterfly recirc valve as does the bypass on a nissan ma09ert.