[danielg]

I did this mod about a week ago, completely removing the return tubes from the OEM BOVs and capping off the intake pipes....Sounds good, I couldn't notice a difference in performance...

Now here's the thing.


During partial thottle, nearing the release of the throttle, it sounds like one is venting before the other. I can actually make both go off seperately if I wanted too. It'd a little hard, but I can do it.

Anyone experience the same thing? I've owned turbo cars, but never twin turbo's with dual BOVs...

Feedback?

[danielg]

Someone? Anyone?

I sounds like it stays open until I apply more throttle or release the throttle. Also, I do not have boost gauge installed, so I can't determine if I'm loosing boost. Not sure sure if this is a bad thing or a good thing.

[BoostedBMW]

Why are you running two BOV's? If you remove the factory diverter valves, all you need is a single BOV.

[danielg]

Still running OEM blow off valves, return tubes are disconnected and intake holes are plugged.

[BoostedBMW]

Originally Posted by danielg

Still running OEM blow off valves, return tubes are disconnected and intake holes are plugged.

Ohhh... ok, I see. If you want to hear a BOV then go and buy one. WalkedU on the forum experienced some boost problems where he couldn't hold boost solid throughout the RPM range. You can take a look at his thread here...
http://www.e90post.com/forums/showth...hlight=DIY+BOV

If you want a BOV though, I would just buy one.

[danielg]

Yeah I know, I just tried it to try it, now I see there might be a problem

[A418t81]

I just read that thread and I think there's something else going on other than just letting the piping blow off to atmosphere vs. in the intake tract. BMW knew what they were doing when they designed the intake and any amount of appreciate vac pulled in it during WOT would be unacceptable so I throw out the "pressure differences" theory, besides the fact that I've been playing with these plastic Bosch DVs for 8 years now and thats never been an issue.

[danielg]

What else do you think is going on?

It makes sense that if you have 2 BOVs that they would release at seperate times, otherwise 2 would be useless. What I don't understand is the reasoning for this, and what it does.

I'm hopefully going to get a procede installled at the end of the week, and if all goes right, I'll be plugging these back in.

[533ogetnom]

. . . did you really think that springs were that precise? thats literally whats determining when they go, of course normally it doesnt matter, but it sounds like your just slowly edging them

[A418t81]

Originally Posted by danielg

What else do you think is going on?

It makes sense that if you have 2 BOVs that they would release at seperate times, otherwise 2 would be useless. What I don't understand is the reasoning for this, and what it does.

I'm hopefully going to get a procede installled at the end of the week, and if all goes right, I'll be plugging these back in.

Honestly, I am not sure Still thinking about it. As far as your DVs venting a different times, its highly unlikely thats actually what is happening. The springs are fairly precise, enough so that any minor variation wouldn't be picked up by your ears. Also, can you verify that they are both getting the exact same manifold pressure reference? If BMW does funny things with the DV's pressure signal, that can cause funkiness but I believe that most of you guys hook your boost gauges up to the DV lines and would obviously see if any funkiness was going on.