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HanSolo71 HanSolo71 is offline
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Default Someone School Me On Why You Install a BOV on the N54 Platform - 05-20-2017, 08:38 AM

I see a lot of builds with BOV added, even with stock turbos. What is the advantage of this over the stock system?
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Cloud9Blue Cloud9Blue is offline
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Default 05-20-2017, 10:38 AM

None. The stock DV is perfectly fine for the job, even under high boost


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HanSolo71 HanSolo71 is offline
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Default 05-20-2017, 10:41 AM

What about aftermarket turbos like the MMP Stage 3?
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Cloud9Blue Cloud9Blue is offline
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Default 05-20-2017, 10:52 AM

Does your dv have a broken diaphragm (you would not hold boost if you do)? If not, there is no reason to change to a BOV unless you want the sound. Just change out the stock charge pipe with a metal one instead like the one bms sells.


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HanSolo71 HanSolo71 is offline
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Default 05-20-2017, 11:49 AM

Quote:
Originally Posted by Cloud9Blue
Does your dv have a broken diaphragm (you would not hold boost if you do)? If not, there is no reason to change to a BOV unless you want the sound. Just change out the stock charge pipe with a metal one instead like the one bms sells.
Nope, just curious.
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ShocknAwe ShocknAwe is offline
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Default 05-20-2017, 04:06 PM

My plastic DVs were leaking boost slightly. That wont happen again soon with the tial valve.


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Cloud9Blue Cloud9Blue is offline
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Default 05-20-2017, 05:05 PM

Quote:
Originally Posted by ShocknAwe
My plastic DVs were leaking boost slightly. That wont happen again soon with the tial valve.
how do you know it is the DV?

the stock DV actually hold its boost by equalizing the pressure on both side of the rubber diaphragm through the rubber vacuum (which is actually under positive pressure during load) line running from the manifold. so unless your diaphragm is torn or your vacuum line is kinked or leaking, there is no reason why the stock DV is the source of the boost leak.

these aftermarket BOV and DV uses springs and heavy pistons to hold boost and typically have a much worse actuation speed than the stock design after trying those out and compared the logs myself.

anyway, stay with stock DVs, they are cost significantly less to replace, perform better, and more reliable (no metal to metal contact). don't believe in marketing BS that some vendors have spread over the years.


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Last edited by Cloud9Blue; 05-20-2017 at 05:10 PM..
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Velocity26 Velocity26 is offline
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Default 05-20-2017, 07:49 PM

Quote:
Originally Posted by HanSolo71
I see a lot of builds with BOV added, even with stock turbos. What is the advantage of this over the stock system?
They make the cool noise when they bleed off the pressure on a throttle cut.

That's about it, unless you are building more boost than the stock DV's can handle.
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ShocknAwe ShocknAwe is offline
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Default 05-21-2017, 06:36 AM

Quote:
Originally Posted by Cloud9Blue
how do you know it is the DV?

the stock DV actually hold its boost by equalizing the pressure on both side of the rubber diaphragm through the rubber vacuum (which is actually under positive pressure during load) line running from the manifold. so unless your diaphragm is torn or your vacuum line is kinked or leaking, there is no reason why the stock DV is the source of the boost leak.

these aftermarket BOV and DV uses springs and heavy pistons to hold boost and typically have a much worse actuation speed than the stock design after trying those out and compared the logs myself.

anyway, stay with stock DVs, they are cost significantly less to replace, perform better, and more reliable (no metal to metal contact). don't believe in marketing BS that some vendors have spread over the years.
That's nice. It was definitely the DVs according to my logs before and after part swaps. Lines were fine. It's not BS, but glad you've had luck with yours.

For whatever it's worth, the stock units held up fine for me until I started targeting north of 15-17 psi.


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Cynical Cynical is offline
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Default 05-21-2017, 09:32 AM

Quote:
Originally Posted by Cloud9Blue
how do you know it is the DV?

the stock DV actually hold its boost by equalizing the pressure on both side of the rubber diaphragm through the rubber vacuum (which is actually under positive pressure during load) line running from the manifold. so unless your diaphragm is torn or your vacuum line is kinked or leaking, there is no reason why the stock DV is the source of the boost leak.

these aftermarket BOV and DV uses springs and heavy pistons to hold boost and typically have a much worse actuation speed than the stock design after trying those out and compared the logs myself.

anyway, stay with stock DVs, they are cost significantly less to replace, perform better, and more reliable (no metal to metal contact). don't believe in marketing BS that some vendors have spread over the years.


I love reading complete lies.
Oem dv are plastic. They leak with stock boost and anything above stock. Are there exceptions to the rule? Ofc.

Aftermarket offerings you are mentioning must be cheap ebay reps. Try buying a quality product. They are all adjustable.

Please keep your alternative facts to yourself. Put them in a jar and bury them in the yard
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Cloud9Blue Cloud9Blue is offline
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Default 05-21-2017, 11:23 AM

Quote:
Originally Posted by Cynical
I love reading complete lies.
Oem dv are plastic. They leak with stock boost and anything above stock. Are there exceptions to the rule? Ofc.

Aftermarket offerings you are mentioning must be cheap ebay reps. Try buying a quality product. They are all adjustable.

Please keep your alternative facts to yourself. Put them in a jar and bury them in the yard
Ah yes, calling my statements lies while offering no facts to back up your own statements. It is folks like you are the reason why we have alternative facts in our vocabulary these days. It would be a waste of time to try to have an actual discussion with you, but I will type up my "alternative facts" below for people actually want to learn something

Yes, the valves are plastics. No where do I mention they aren't. If they are leaking at high boost, they must leaking from the connection between the charge pipe and valves. This is why a metal aftermarket charge pipe that uses clamps are better than the stock connector that uses twist lock and some skinny o-rings.

The aftermarket parts I tried are turbosmart, which is far from a cheap eBay knockoff, they operate the same as all the other aftermarket BOVs and DVs. These pneumatic valves use the delta P between the manifold (which will be under vacuum after throttle closeure) and the charge pipe to operate, so you really want them to respond as quickly as possible after the throttle is closed. The spring actuated pistons in these aftermarket designs takes significantly higher delta P to actuate than the stock one, which leads to boost spike.


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klipseracer klipseracer is offline
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Default 05-21-2017, 12:09 PM

Our cars use a MAP(TMAP) sensor so there is no harm in using a BOV. Diverter valves are more than sufficient if you upgrade them.
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Beemin Beemin is offline
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Default 05-21-2017, 01:18 PM

I have to agree with cloud9. The stock DV's are underrated. It's a great design and mine are holding just fine at 25psi.

I've read comments online from people that say their DV's are leaking but I think that's more due to people blaming leaks on them because it's convenient. Being around n54s a lot I've never seen a failed stock DV. I'm sure there are real cases with leaking DVs (like shockanawe's) but I believe it's the exception, not the rule.

If you just want the wooosh pull the hoses off.
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rkreimer10 rkreimer10 is offline
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Default 05-21-2017, 02:58 PM

I relocated my intakes to the hotside. Does not make sense to try to install stock diverters because there isn't an option to reinstall them.

This is why I chose to go with a tial Q.
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Cloud9Blue Cloud9Blue is offline
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Default 05-21-2017, 04:51 PM

Quote:
Originally Posted by rkreimer10
I relocated my intakes to the hotside. Does not make sense to try to install stock diverters because there isn't an option to reinstall them.

This is why I chose to go with a tial Q.
Could have just put one these on the stock DVs instead.

https://www.knfilters.com/vent.htm


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ShocknAwe ShocknAwe is offline
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Default 05-21-2017, 05:08 PM

IF you pull the hoses off the stock DVs, you'll want breather filters. Unless you just really enjoy cleaning oily spatter off engine bay components that is.

Went through a few different configurations on my car before settling with the 50mm CP/Tial valve. Now, if you just want loud woosh pulling/capping the recirc and putting filters on the DVs will get you there.


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Default 05-22-2017, 04:57 AM

I put a Synapse BOV on mine and it works great. Very fast actuating.
I think you are very close to me (Hospital and Cooley), let me know if you want to check it out?
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bnk bnk is offline
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Default 05-22-2017, 05:50 AM

Quote:
Originally Posted by Cloud9Blue
Ah yes, calling my statements lies while offering no facts to back up your own statements. It is folks like you are the reason why we have alternative facts in our vocabulary these days. It would be a waste of time to try to have an actual discussion with you, but I will type up my "alternative facts" below for people actually want to learn something

Yes, the valves are plastics. No where do I mention they aren't. If they are leaking at high boost, they must leaking from the connection between the charge pipe and valves. This is why a metal aftermarket charge pipe that uses clamps are better than the stock connector that uses twist lock and some skinny o-rings.

The aftermarket parts I tried are turbosmart, which is far from a cheap eBay knockoff, they operate the same as all the other aftermarket BOVs and DVs. These pneumatic valves use the delta P between the manifold (which will be under vacuum after throttle closeure) and the charge pipe to operate, so you really want them to respond as quickly as possible after the throttle is closed. The spring actuated pistons in these aftermarket designs takes significantly higher delta P to actuate than the stock one, which leads to boost spike.
This.

Generally people don't understand that it is not the DV that is leaking, but the connection.

Have you upgraded the connections, or are you just buying the stock parts when the leaks appear? How often do you do need to do the maintenance? I know you track your car, so an average Joe should not need to replace the DV-hardware that often.
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Tony@VargasTurboTech Tony@VargasTurboTech is offline
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Default 05-22-2017, 05:54 AM

Using a BOV has nothing to do with how much boost the stock DV's can hold. You are looking for proper venting, with proper response designed to eliminate compressor surge. THE ONLY THING A BOV IS DESIGNED FOR IS TO ELIMINATE COMPRESSOR SURGE. Not to sound cool, not to look cool, not to hold more boost. Some of those may be a side effect, but they are installed to eliminate surge, any one who tells you differently has no clue what they are talking about. If you want some real information, not a bunch of internet warriors, look up articles by Tial, Turbosmart, people that actually make the valves, lots of good reading. For the platform, we put together this simple article to help people understand why a BOV is a great upgrade. http://www.bimmerboost.com/showthrea...Surge&p=758037


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Default 05-22-2017, 06:05 AM

Quote:
Originally Posted by Tony@VargasTurboTech
Using a BOV has nothing to do with how much boost the stock DV's can hold. You are looking for proper venting, with proper response designed to eliminate compressor surge. THE ONLY THING A BOV IS DESIGNED FOR IS TO ELIMINATE COMPRESSOR SURGE. Not to sound cool, not to look cool, not to hold more boost. Some of those may be a side effect, but they are installed to eliminate surge, any one who tells you differently has no clue what they are talking about. If you want some real information, not a bunch of internet warriors, look up articles by Tial, Turbosmart, people that actually make the valves, lots of good reading. For the platform, we put together this simple article to help people understand why a BOV is a great upgrade. http://www.bimmerboost.com/showthrea...Surge&p=758037
Class dismissed.


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Cloud9Blue Cloud9Blue is offline
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Default 05-22-2017, 08:10 AM

Quote:
Originally Posted by bnk
This.

Generally people don't understand that it is not the DV that is leaking, but the connection.

Have you upgraded the connections, or are you just buying the stock parts when the leaks appear? How often do you do need to do the maintenance? I know you track your car, so an average Joe should not need to replace the DV-hardware that often.
I am using the bms charge pipe, so the stock dv are clamped down to some high temp 3-ply silicone ***** I got off McMaster, not a fan of the cheap rubber hoses that come with the pipe. I did run into problem with leaking connection at high boost, but a few more turns at the hose clamps solve the issue right away
I have no reason to believe the rubber diaphragm will ever leak though. I will probably just put some breather filter on these if I go single turbo down the line. There really is no point wasting money on a new charge pipe and BOV. The stainless steel pistons inside the turbosmart DVs were scratched up quite a bit after just two weeks on my car, even though I l lubed the thing thoroughly before installing. So I doubt these metal piston design will last as long as the factory ones.


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Last edited by Cloud9Blue; 05-22-2017 at 08:19 AM..
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NoQuarter NoQuarter is offline
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Default 05-23-2017, 09:43 AM

Quote:
Originally Posted by Cloud9Blue
The stainless steel pistons inside the turbosmart DVs were scratched up quite a bit after just two weeks on my car, even though I l lubed the thing thoroughly before installing. So I doubt these metal piston design will last as long as the factory ones.
Depending on how "thoroughly" you lubed them perhaps grit stuck to the lube and then caused the scratching?
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Default 05-23-2017, 10:13 AM

The DV's on our cars are very similar to the ones used on many VAG and Porsche turbo cars and they work just fine for most applications. I specifically chose my Cobb charge pipe to retain the stock valves. I ended up venting them to atmosphere because of my MR5 setup but didn't intend to originally. I'm 17psi all day long. Now that they are venting to atmosphere, I get all the cool kid ricey noises now too so my scene points are mad yo.


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Cloud9Blue Cloud9Blue is offline
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Default 05-23-2017, 11:15 AM

Quote:
Originally Posted by NoQuarter
Depending on how "thoroughly" you lubed them perhaps grit stuck to the lube and then caused the scratching?
Why would I go through the trouble lubing them and just get whole bunch of abrasive particles stuck on them during the process...


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NoQuarter NoQuarter is offline
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Default 05-23-2017, 11:25 AM

Quote:
Originally Posted by Cloud9Blue
Why would I go through the trouble lubing them and just get whole bunch of abrasive particles stuck on them during the process...
Wasn't implying you got abrasive particles stuck during the process of lubing them. Just that the lube itself may have allowed abrasive particles from the engine bay/air to stick over the course of a couple weeks.You didn't say what lube you used.
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