Tory,
Which EFR turbo and trim is being used in the MTNTK kit? (what Map are you showing above?)
Is your system making positive manifold pressure (>14.7PSIa) at engagement?
Does MTNTK have any tables on lb/min demand at consistent manifold pressures for the 800 AXYS engines over the RPM range while pressurized?
It would be nice to see what these engines "need" in terms of mass/flow/pressure.
Also... Have you put a vacuum gauge at the reed vacuum reference point to see what it is reading at idle?
Then see what vacuum is required to begin to lift the CRV... set the spring pressure at just slightly above that
and you, IMO, will have an optimized BOV-circuit for your configuration.
It is nearly impossible to get rid of some flutter when you chop the throttle..but it's good, from a performance perspective, to try to minimize it.
.
They use a 6258 with.64 AR.
According to my boost gauge, it is still reading vacuum at engagement. Granted I have my engagement a little lower than typically seen in turbo clutching.
No they don't. Getting accurate lbs/min would be pretty difficult without a boat load of instruments. If you want to try to guess: http://www.turbos.bwauto.com/aftermarket/matchbot.aspx
Reference at the reed cage is looking for a delta between compressor pressure and post TB, not necessarily vacuum. I talked to BW and Mtntk, they do not offer a lighter rate spring. Mtntk said that they never had this flutter on the Pro kit, but now that they added the intercooler and the 800HO making more power, they get a bit of flutter at higher boost levels.