How many twin turbo set ups use a BOV?

Extended Power · Jan 30, 2012

After the little time I had running my set up, I would like to add a BOV to the system.
I was looking at BD Powers unit, but isn't there anything else that works without an electronic controller? (I've got enough chit to calibrate as it is...)

Which BOV are you using, and are you happy with it...pictures are always nice too.

opcorn:

Cutting-Edge Diesel · Jan 30, 2012

I dont have one on my compounds but i used one with the procharger set up i had. it was the BD one. Once you had it fine tuned you didnt have to mess with it. I thought it was nice to be able to adjust it electronically because they can get very annoying if they open to much, but that might not be that big of a factor with compounds as apposed to the procharger.

Charles · Jan 30, 2012

If not electronically, how would it work? It's not as if you've got hugh swings in vacuum from an opening and closing throttle valve to use instead.

Secondly, what is the intended point of the relief? I honestly don't understand what it is supposed to do. Why do I ever want to vent manifold pressure to atmo? I'm seriously asking anyone who finds a BOV useful on a diesel.

Extended Power · Jan 30, 2012

I just know with all the "Quick-on" "Quick-off" driving I did, the turbo's barked all the time.
Seems easy enough to hook one up using drive pressure and boost pressure...once you let off the go pedal, the boost is higher then the drive pressure, and walla...relieve all excess air instead of trying to spin the turbos backwards...

I see E.D speaks of one, but it's not on their site.

Do you still have the BOV from the SC/turbo combo, or did it go with the set-up?

Extended Power · Jan 30, 2012

Charles said:
If not electronically, how would it work? It's not as if you've got hugh swings in vacuum from an opening and closing throttle valve to use instead.

Secondly, what is the intended point of the relief? I honestly don't understand what it is supposed to do. Why do I ever want to vent manifold pressure to atmo? I'm seriously asking anyone who finds a BOV useful on a diesel.

It works by using the drive pressure and boost pressure.

The intent of the relief is to protect the turbo's from stalling after a hard run, and pulling my foot off the go pedal, and standing on the brakes.

Cutting-Edge Diesel · Jan 30, 2012

Extended Power said:
Do you still have the BOV from the SC/turbo combo, or did it go with the set-up?

I sold it

Charles · Jan 30, 2012

So you would run drive pressure to hold the BOV closed, then maybe a spring pressure that would hopefully keep the valve seated at light power when drive was low, but boost was getting on up there?

I'm afraid it might be tricky to find a spot where the spring pressure would be high enough to hold the valve shut when at part throttle to moderate throttle/rpm but still open up enough to matter when you lifted and drive dropped even more relative to boost.

91turbogsx · Jan 30, 2012

There was something on CompD I believe about this. Someone made one that did as said using drive pressure and boost pressure. Not sure how it worked out though.

Extended Power · Jan 30, 2012

The drive pressure off the manifolds is quite high until the diverter valve opens up on the secondary....maybe using a 10-15 psi spring would work?
I had the diverter valve set to start opening up at 8.5 psi+ boost pressure...regardless of the backpressure.
With a 10 psi spring, and the back pressure...it would hopefully hold shut most of the time, and just open when really needed. (20+ psi difference between the boost and drive pressures)

Extended Power · Jan 30, 2012

91turbogsx said:
There was something on CompD I believe about this. Someone made one that did as said using drive pressure and boost pressure. Not sure how it worked out though.

That's where I saw it!

I don't want any problems with stalling these turbos...
Forcing the air out a relief instead of back through the turbos and out the air filter seems like a better idea.

TRUBBS · Jan 30, 2012

From my take on it, you run Bp to it to hold it down/shut then when the Bp drops off it allows it to open. I'm still learning how they work on diesels also...

wetnsloppy4x · Jan 30, 2012

Let me preface by saying I have 0% experience with a BOV on a diesel. However, I see the challenges being similar to gasser stuff in the tuning department.

Where were you planning on dumping the BOV discharge? If venting to athmosphere, you are dumping previously metered air which can lead to a tuning nightmare.

OTOH, if you plumb your discharge to post-MAF and pre-turbo, you should be OK in this department.

Sorry if you've already considered this. In the tuner world you see lot's of bro types slapping on a BOV vented to athmosphere on a MAF motor and wonder why they cook their motors so I thought I'd point it out. Not that I think you're a bro type EP. LOL

Worstenemy453 · Jan 30, 2012

What ive always heard is that they are beneficial on a gasser because of the way they are set up. On a diesel i see it like a 6.0L, when you et into real hard and let off it just pushes back into the intake hence the "turbo farts", and ive been told a diesel can hold up to this because of the way they are set-up as opposed to a gasser.

Id be interested to learn more on the subject myself.

91turbogsx · Jan 30, 2012

JGS Turbo is who started making a mechanical BOV recently. I read a whole thread on CompD a while ago. He used a Drive Pressure Particle Trap that I believe he came up with as well.

Extended Power · Jan 30, 2012

Worstenemy453 said:
What ive always heard is that they are beneficial on a gasser because of the way they are set up. On a diesel i see it like a 6.0L, when you et into real hard and let off it just pushes back into the intake hence the "turbo farts", and ive been told a diesel can hold up to this because of the way they are set-up as opposed to a gasser.

Id be interested to learn more on the subject myself.

Yes, a diesel can handle the "farts"....its the turbos that snap shafts when chit happens at extreme pressures. And if nitrous is involved, even more so.