Upgraded DVs vs. BOV experience?

[E30 Racer]

Have any of you tried both, ideally both used in conjunction with an ER charge pipe? Other than the sound, what was your impression? Any difference in lag or oscillations in gears 3-6?

[1speedbike]

Theoretically, you're right. Using DVs to recirculate the air instead of just letting it escape through a BOV should be better for performance.

However, on our particular cars, there is no real consensus. Some people like BOVs better and some people like DVs better.

I've seen other arguments like the BOV will give you slightly better response since the air can escape right away instead of having to be recirculated through the DV tubes. Another argument is that the DVs redeliver the air such a way that it causes extra turbulence in the intake track and that's no good.

Also, if you're driving an automatic, all of this matters even less because you don't really pick up your foot during shifts.

[Freon]

I doubt it matters either way. It is nice to have a valve that is adjustable, though.

[ErvGotti]

I've ran both a Greddy type R BOV with the Z shift pipe and currently Forge DV's on the stock pipe. To me there is no noticeable difference between the two besides the sound. The N54 runs off a MAP sensor in place of the typical MAF sensor so as long as your DV/BOV is holding boost the performance will be the same with both.