Any value to aftermarket BOV/DV on 2011 135i with DCT?

[monkeypotomus]

Greetings all knowing gurus!!! LOL
I am new to this forum and to the turbo tuning world in general, so sorry for this noobish question.
I have searched around quite a bit and not been able to find the info I need to make a decision.

If I understand the purpose of BOV/DV (questionable), it is to reduce pressure on the intake side of the turbo motor when coming off the throttle.
This seems like an important thing, however I know the stock DV exists and is doing its job currently.
So, to my question:
Is it worth the expense to get an aftermarket BOV/DV if I have the DCT?
(I do have a chance at a good price on a very good BOV/DV)

I am not coming off the throttle during shifts, so I am not sure how much an aftermarket DV would help. Only additional question:
Will the stock DV hold up if I am increasing boost using one of the many tunes that are available? (potentially after 14, 15..17 psi?)
Thanks for any advice or guidance!

[ErvGotti]

The 2011 135i N55 motor has a MAF sensor instead of the TMAP sensor in the N54. What this means is that you will not be able to run a BOV properly without being tuned for it.

You could upgrade your DV, but I haven't seen anything out yet for the N55.

[shockin330i]

Also, I believe the dv is connected by the turbo...

[monkeypotomus]

Yes, my setup would basically be the first my shop has done on an N55 135i, although they have done a 335 N55 with the same kit, thinking it will be very similar if not the same.
I am really just wondering if the tune compensated for it, and all things were right in the world, would it be worth expense (I could get a good deal, but it is still expensive).
Is the DV really helping a DCT all that much....maybe at higher boosts it will matter....again, really new to this, so just looking for opinions....and appreciate yours!

.....and yes with MAF, I definitely don't think a BOV (diverting to atmosphere ) would work.....

[BerkTechnology]

You will get that cool BOV sound but the car will run like shiet. Not sure how much value is in there. haha

[ErvGotti]

Originally Posted by monkeypotomus

Yes, my setup would basically be the first my shop has done on an N55 135i, although they have done a 335 N55 with the same kit, thinking it will be very similar if not the same.
I am really just wondering if the tune compensated for it, and all things were right in the world, would it be worth expense (I could get a good deal, but it is still expensive).
Is the DV really helping a DCT all that much....maybe at higher boosts it will matter....again, really new to this, so just looking for opinions....and appreciate yours!

.....and yes with MAF, I definitely don't think a BOV (diverting to atmosphere ) would work.....

If the stock DV is anything like the N54 you should be able to hold up to 14- 15 psi. That seems to be the norm for the stock DV's on the N54. I'd say if your planning on going up to or pass that PSI then yes, you should upgrade your DV. As far as helping your DCT, the short anwser is no. The DV is there to prevent compressor surge and an upgraded DV will only allow you to hold higher boost.

Do not upgrade your DV unless your pushing more boost, you will not gain anything by upgrading it with the stock boost.

[monkeypotomus]

OK, that is what I was thinking, thanks for the response!
Now the dilemma is that I will be getting a tune (piggyback, flash, Cobb AP....) eventually, which might put me on the threshold of 15+ psi, so I guess that would be the time to potentially invest in an upgraded DV...
Better to put my first dollars into DP and axleback (and tune).

[Freon]

If you dump MAF metered air the ECU almost certainly has no algorithm to account for that loss, so it isn't even a matter of getting it "tuned" for it. First the logic has to be there before it can be "tuned".

On Subarus, Forge, TurboXS, and Perring made replacement recirculating valves. I wouldn't be surprised to see some show up for the N55.

[pwdrtoastman]

a bypass valve is a pretty generic thing to swap out. I have run open and closed systems on metered air set-ups. I've never had any serious issues at all, and i've monitored the ECU through a piggy back system. The two minor issues, i've seen; a/f went lean for a split second during shift(no knock), and a nice gargling noise coming from the exhaust after shifting.
feel free to upgrade it, i dn't see any issues at all. I would rather have a better bypass valve in there and enjoy a little more of the "whoosh" sound.
You can even buy a bypass valve that doesn't require any tuning, and most blow off valves have recirc kits.
To answer you question yes, its worth the money. A forge bpv cost 130 bucks, provides a better bpv, quicker reaction, and adds more security.

By security, I have a forge bpv set up on my evo ix(500whp). You can set up the valve so it bleeds off boost, almost like a wastegate, based on how tight or loose you make the spring.

[HondaGoneRogue]

The gargling noise you heard was an overly rich condition and that over time fouls your plugs quicker. Not sure how that would work with DI. Also, on some cars the richening is enough to stall the car on rapid deceleration (like pushing the clutch in and letting revs drop). Many tuners and standalone have anti-stall programs just for this reason. So I wouldn't say that running a VTA BOV on an N55 is completely safe and proper unless recirculated. Even then the disruption could cause hiccups.

[pwdrtoastman]

My last platform was DI, its one hell of a learning curve.

[TreDirtyFive]

the n55 DV is electronic right? maybe I'm wrong.