Agreed Steve .SteveN said:No, i TOTALLY understand the theory behind it, if you look at it purely from books etc, they are vital.
But NOTHING beats practical testing.
And testing proved to me they not half as vital as they seem on paper.
Paper and reality are two different things, regardless of how complex the books are.
Like said from the start, id never reccomend it as never tried it on GTRs, but tried it on plenty other cars at far higher boost than most GTRs to know that personally id take the risk to see what it was like, but if there no reason to on your car, then dont bother.
From a performance side, many dumpvalves that vent a lot of air can often make throttle response worse rather than better...
DV valves are better than vent to air normally so the recir on the GT-R are a better bet and make a lot more sense. Unfortunately there is now a habit to put BOVs are hybrid valves that dump some air to atmos and recir the rest onto cars for "effect".
As you said you have noticed no problems so far but the damage is usually long term and can show up in differing failures than expected (exhaust side problems as the two sides are connected).
The type of turbo and boost levels etc are the main factors in whether you can get away with. If the turbo blades are strong enough and the pressure difference between each side is not enough to break the oil film with the unequal spiralling side forces, the shaft bending/rebound (all materials are like rubber (quoting Royce) i.e. all bend under stress) during this time etc then it will "probably" do no harm at all to remove it.
Also depending on throttle plate opening/closing during shift times etc and how much the DVs leak and energy lost during recir travel etc it may make little difference to the performance or may even help to remove them (less weight also) in some cases.
My problem is I can't see it being a good idea for normal Joe Public to do so, maybe for a tuner on a car that no longer is anywhere close to the original spec it would be of benefit to try it out but it can be a costly exercise in the long run (to the next owner normally) but may benefit in the short term if you are trying to get good 1/4 times etc.