[chiefsotos]

Hello, three months ago while i was trying to install a boost gauge, i broke up the Y connection (the one which connects the boost solinoid coming from engine and ending at diverted valves). I took it to bmw dealer and because he didn't have Y connection, put me a T connection and made the connections as they appeared in diagram no: 1. Furthermore one day layter i installed a procede v3 and 2 cones filter. After that when i stepped of the gas pedal the blow off valves made a very nice sound (woooosshhhh). I thought that this was normal because of the 2 cones filter. The maximum boost spikes (when i step off the gas pedal) i saw at dataloging were 18.9psi
About one week ago the T connection between the blow off valves broke. This time i ordered from the Bmw the original Y connection and i made a correction in all the solinoid connections as they appear in diagram No: 2.
Now when i step off my foot from the gauge pedal the blow off valves doesn't make any woooshhh sound (i don't hear it at all). The dataloging now shows only 16.8psi boost spikes, when i change gears.
My questions: 1) Is it normal for the blow off valves to not hear them(i remind you that i have 2 cones filter)?
2)I noticed that the holes of Y connection are a little smaller than the holes of T connection i had from boost gauge. Is it possible that the blow off valves doesn't opperate correctly and make a damage to my turbos? Or they worked wrong with my previous connections(diagram no: 1) and that was the reason i heared them make the wooshhh sound?
Guys with 2 cones filter please tell me if you hear them made the wooshhh sound in the car with close window.

[Sniz]

I doubt the Y vs the T would make much a difference. One thing, check both the Y and the T you have installed right now and make sure you can blow air through the connectors in all directions. Twice now I have had those little pieces clogged by fautly manufacturing, causing ill effects.

also, when datalogging, dont pay attention to the boost spikes at throttle closure, rather pay attention and monitor the sustained boost you are seeing during full throttle runs.

As long as your T and Y connectors can pass air, your fine.

[chiefsotos]

My subtained boost via dataloging is under 14psi. I noticed that the holes of Y connection is a little smaller in diameter than in the T connetion i used to have. But now i don't know which situation was right: the one that i am now(the blow off valves doesn't make any wooshhh sound) or the one i was for about three months (pretty strong wooshhh sound from blow off valves).
Please people with dual cone intakes and a tune enlight me about the sound!!!

[GGreek5]

You should be hearing the sound from the Diverter valves. Especially since you have the dual cones, the sound would be louder. Do you have aftermarket Diverter valves or the stock ones??

[AlpineG05]

I'm running jb3 with the single log filter pretty much the same as dual cones and I always have that woooosh when letting off the gas. sometimes its louder all depends if you were punching it or not. I suppose u should hear the turbos sucking in air and then the woooosh.

[Mr. 5]

I don't think it would matter.

[chiefsotos]

I hear the turbos spooling when accelarating but not the wooshhh sound when let it of. I wonder if the blow off valves doesn't close completly because i noticed that the Y connection holes are a little smaller in diameter than the T connection i used to have. In that case my turbos spin harder right?
I saw maximum 15 psi boost in the gauge but in datalogin it is only around 14psi. If something blocked the solinoids which connect the blow off valves and do not opperate corectly shouldn't i have been in a limp mode? Because when the T connection broke and i had a leak in these solinoids i had also a limp.

[ac2]

I installed a boost gauge few days ago, and it hooked up like the diagram 1 shown above. The result is compressor surge.
My car sounded like this car in this video. http://www.youtube.com/watch?v=OuNTnA5A2Fo
Afterward, I reconnected the boost gauge like the diagram 2, then the compressor surge sound went away.

[Ilma]

I just checked my boost gauge connection today after reading your post.

It is identical to your diagram #2 and I hear the whooshing sound of my diverter valves all the time with my dual cone intake.

If I were in your shoes, I would definitely make sure that air is flowing freely through the T and Y connectors as others have already suggested.

[Ilma]

Originally Posted by chiefsotos

I hear the turbos spooling when accelarating but not the wooshhh sound when let it of. I wonder if the blow off valves doesn't close completly

I would think that if the valves aren't closed completely then you would hear a whoosh sound constantly since they would be bleeding boost.

IF you are not hearing the blow off sound, then its probably more likely that the diverter valves are NOT OPENING when they should.
They work on the concept of pressure differential before AND after the throttle body. So when you close the throttle, a vacuum is induced into the intake manifold which signals the diverter valve to bleed off the building boost on the other side of the the throttle body.

That vacuum signal is carried by the vacuum line you connect your boost gauge to. So another thing to watch out for is whether you are getting a vacuum reading on your boost gauge when you close the throttle. If not, then the vacuum is not reaching the diverter valves and your T connector is probably clogged and blocking that signal.

[scalbert]

A Y or T do not matter. There is no measureable flow and the pressure changes will be identical.

[Ilma]

Originally Posted by scalbert

A Y or T do not matter. There is no measureable flow and the pressure changes will be identical.

There is definitely flow to the diverter valves.....you can hear it.

You must be referring to the boost gauge connection I hope.

[scalbert]

Originally Posted by Ilma

There is definitely flow to the diverter valves.....you can hear it.

You must be referring to the boost gauge connection I hope.

Not to that side of the diaphram. The control signal does not have flow. The process side does; the intake piping.

[Ilma]

K...makes sense. So the vacuum and boost pressures are static once acheived?

[scalbert]

Originally Posted by Ilma

K...makes sense. So the vacuum and boost pressure signals are static once acheived?

Correct.

[chiefsotos]

Originally Posted by Ilma

I would think that if the valves aren't closed completely then you would hear a whoosh sound constantly since they would be bleeding boost.

IF you are not hearing the blow off sound, then its probably more likely that the diverter valves are NOT OPENING when they should.
They work on the concept of pressure differential before AND after the throttle body. So when you close the throttle, a vacuum is induced into the intake manifold which signals the diverter valve to bleed off the building boost on the other side of the the throttle body.

That vacuum signal is carried by the vacuum line you connect your boost gauge to. So another thing to watch out for is whether you are getting a vacuum reading on your boost gauge when you close the throttle. If not, then the vacuum is not reaching the diverter valves and your T connector is probably clogged and blocking that signal.

When i Close the throttle the boost gauge indicates the correct vacuum so today i will check the Y connection. When you disconnect completly the vacuum line the blow off valves remains constantly open or close?

[scalbert]

Originally Posted by chiefsotos

When you disconnect completly the vacuum line the blow off valves remains constantly open or close?

Closed.

[chiefsotos]

After two hours of changing the connections betwwen the vacuum line, boost gauge and blow off valves (about 6 variations) and testing the car i think i find the solution.The "loud" wooshhh sound i used to hear for 4 months now (i hear it preety loud even with windows closed) was only when i made the connection as in the diagram no 1 (in my first post) and only when i used the faulty T connection(You can see it in the photo bellow).
When i used the Y connection and a good T connection the blow off valves make some woooshhh sound but you can hear it only with windows open.
So for months now i used in a loud wooshhh sound and now replacing the faulty T connection with the proper one i thought that something was wrong with the blow off valves. I think that was the reason why in dataloging i saw 18.9psi boost spikes (with the faulty T connection) and now with the new ones i saw only 16.5psi.
Now i wonder two things: 1) Was the loud woooshhhh sound i used to hear cause of that blow off valves didn't open when they should to and suddently when the presure in the manifold exceed a certain psi level opened violently? 2)Or this loud whoosshhh sound was something else?
3) I hope while i drove the car, all these months (about 5000Km distance), under these conditions i didn't messed the engine parts a lot...

[scalbert]

It could have been blocked or had a restrictor in it.

[branabolic]

does it really matter whether it is hooked up like diagram one or two? i think mine is like diagram one and i have never really had problems but i am also stock tune and div. valves.

[chiefsotos]

Originally Posted by branabolic

does it really matter whether it is hooked up like diagram one or two? i think mine is like diagram one and i have never really had problems but i am also stock tune and div. valves.

After several experiments i make with T connection i realized tha if the airflow is good then there is no problem no matter how you connect the T connection. I had problem only with connection like diagram 1 only when i used the very faulty side of T connection (you can see it in picture 2)