this is a question for people with turbo cars or turbo knowledge. i have heard that venting 2 the atmosphere will cause a slight richeing of the fuel air mixture when the bov hits. but wouldn't that not make a huge difference? i have heard it may cause damage but i dont see how. i have also hear that when u vent to the atmosphere that it will may ur turbo stop spinning for a brief moment which will cause some (perhaps minor) damage. i have also heard that if u vent to the atmoshpere then when u put your car into nuetral, as lets say ur pulling up to a stop sign, it will want to die. most of the time the engine will catch itself and not die but i do know of one person with a blitz bov that whenever he puts it into nuetral his car will die. please help me figure out what is better for the engines life and turbo life.
my perdiciment is wether to recirc or vent on my fb project. i really like the sound of the bov but if its going to take years off the life of my engine or turbo than screw that.

i would like everyone with professional knowledge or experiance to help answer this question. aka i wanna hear a lil from blake and the atkins peeps and the unnatural peeps as well.

 

Best to have it recycled. Its definatly a good idea if you have a mass air flow sensor and/or a stock ecu. It will run rich if you have the maf and stock ecu. Good luck!

 

[QUOTE=MWMburton;6982973] i have also hear that when u vent to the atmosphere that it will may ur turbo stop spinning for a brief moment which will cause some (perhaps minor) damage. [QUOTE]

ehm no. that scenario would be caused by a turbo setup ran without a bov, when the throttle plates closed, it would cause a pressure build up which will force the turbo to spin backwards. turbos in reverse are no bueno

 

^^^yah i know that and in that situation it can also backspin which is no bueno either.

but will running a little rich hurt the engine? i have heard that richening the fuel will increase power as long as it isnt too rich. same goes for leaning the fuel out

 

most people open vent with standalone ECU's running a map sesnor. if your running an AFM you'll probably have to recirculate. ive heard of idle problems, etc.

 

JUst vent it to atmoshpere, I ran my like that for two years, always idles fine. Never even shoot flames when shifting under wot. I have never known a rotary to explode or get hurt running a little rich. On the other hand I have seen a few explode running 14psi on stock fuel and a tmic. Those are your important upgrades.

 

One problem with venting to the atmosphere is that when your running under vacuum the BOV is open, meaning you’re pulling unfiltered air through it and you’re bypassing your MAF sensor. It would be wise to recirc aft of the MAF. Or add a air filter to the BOV if you want that blow off sound, but are willing to deal with the engine decel stumble.

 

Absolutely not, The bov is not open under vacuum. It has a heavy spring that presses it close, it takes the vacuum along with the boost spike caused by closing the throttle plates to overcome the spring pressure and open it up. Try spaying it with ether while its idling at -18 vacuum, nothing will happen. If it starts to stumble, you should toss out your bov.

 

agreed.

a bov works off pressure differential. when your on the gas during boost or vacuum you have equal pressure after throttle plates and before throttle plates. when you boost then let off gas you get a pressure differential (more pressure before throttle plates) and you overcome spring pressure thus opening valve.

 

Depends on how much vaccum there is, how heavy a spring you have and wether you have a push or pull type bov.

Push type with a low to mid boost spring under high vaccum ~ 25-30 inhg you will see bypass.

With a push type bov setup for high boost you guys are correct you will never see bypass. - http://videos.streetfire.net/video/4...ee0182efa3.htm

Pull type bov will alway have bypass - http://videos.streetfire.net/video/6...3f0150f005.htm

 

Wow great vids... Nice to see how my HKS works. Apparently the Synchronic BOV is much faster, but I have no complaints whatsoever with my HKS. Very pleased =)

 

i have a tial 50mm, on a stock ecu, and no complaints here. i havent had a problem with it leaking. plus rotoaries dont pull all that much vaccuum either...

 

I'm on the list to get two of those synchronic bov units from the first available batch. I plan on running two, one near the turbo (recirc) and one near the throttle body with a filter. This setup should improve throttle response (improved heel-toeing, mid corner on-off-on throttle, etc)

Plus, later on they will provide an upgrade for over boost protection (popoff valve)! Say goodbye to boost surge.

 

good vids. thanks for the info. aren't almost all bov's ie apex i twin chamber, greddy types, etc. push type though?

 

yea at idle. but on decel you will pull a strong vac. ie 25-30" if your not somethings queer.

 

Correct. Most companies (GReddy, Apex'i, TurboXS, Tial, TurboSmart) make push type BOVs. From what I have read the pull types are better at holding higher boost levels than the push. The push is more likely to leak under higher boost levels (20psi+) unlike the pull type which is held shut by the boost pressure.

 

These are some really solid units. I shipped one out to a customer today. Got to spend some time up close with one, these things are huge!

 

hmm, I wonder where I'm at on the list? You got anymore?

 

so with stock ECU and stock Bosst on '99 spec turbos I am interested in that synchronic BOV. does anyone have there website with more info? The videos were very helpful. My only question is that they demonstrate compressor surge, but at the end of the second video when the s2000 drives by it almost sounds like it to is having compressor surge?

thaks

 

I don't believe it is surging. Sounds more to me like the BOV doing it's job and that is just the noise it makes. Doesn't sound quite like turbo surge... I've heard it A LOT!