Here's a picture of a Block Off Plate I made with "extra" vacuum nipples. One goes to the boost sensor and the other to the blow-off valve...

 

What doesn't make sense is that if running woithout a BOV is so dangerous then why are they almost completely absent from nearly all forms of top-level motorsport that allow turbos (endurance racing in particular)? Forget the argument that "they replace the turbo every race"; if such a simple and relatively cheap device could genuinely reduce the chance of turbo damage, they would be far more common. You talk about risk, but if it were genuine it's not a risk teams would take. IMO we're talking about a myth that has been blown way out of proportion, most likely in the interests of selling more over-priced aftermarket BOV's.

Because (a) all turbo'd cars made in the last two decades came with one and (b) for some reason a lot of people are obsessed with making ***** look-at-me noises. If they really were to prevent damage, then maximum flow would be the most important criteria. Instead people ask for (and manufacturers design for) maximum noise. I suspect a BOV engineered for maximum flow would be quieter than most aftermarket ones...

All manufacturers use recirculating BOV's for noise reduction, i.e. to prevent the very sound the OP is worried about. No because this is damaging anything, simply because it's an undesirable noise to most people. It evens states this in the FSM.

My old 12AT had no BOV for it's entire 20+ year life and yet its turbo lasted as long as any can be expected to and was eventually rebuilt for the same reason many are (oil seal). I disconnected the BOV on my RX-7 just to see what it sounded like and ran it like that for months. I swapped the turbo out for an upgraded S5 one recently, and despite never having been rebuild it's in excellent condition with no damage done in it's BOV-less time.

Good to see someone else finally do this.

 

The only reason that I brought it up was I felf that there was something wrong with my car. I took the greddy bov off of my friends 7 wich I know makes a loud noise(letting out air with no surge) and put it on my car. It does not seem like it is as nearly effective on my car. I could care less about the sound it makes or whatever but with the surge issue it just sounds like if the bov was working right maybe I would not have the surge problem. I mean if it was just a little bit of surge maybe I would not worry as much but it seems like it is pretty bad.... maybe not?? The only reason I worry is because the bov does not seem to be doin what it should. Rather than say "well I dont need it anyway" i would like to try and find out why things are not working properly. I dont want to have to "deal" with a surge problem if I dont have to. I guess I want to be better safe than sorry?? Maybe I am wrong tho??

 

Help me guys... there has got to be someone who has had this problem before. Hopefully someone has some ideas cuz i got nothin

 

Ok I have some more info on this problem that I am havin. I might have been lookin in the wrong direction for this issue. My bov is working but just not all the well and loud. Turns out I am only boostin like 5 psi, which i believe is why my bov is not that loud. I thought there was a problem with the turbo because I was told by the guy I bought th car from that it was set a 13psi. I am on a microtech so maybe all my problems can be solved by a tune??? Could there be any other explanation for the problems I am havin?? Tell me what you guys think.

 

Any thoughts at all guys??? I would like to hear anything you have to say about this

 

^^^help^^^help^^^

 

Still lookin for some info guys. Just let me know anything that you think... what are your thoughts??

 

"""Ok I have some more info on this problem that I am havin. I might have been lookin in the wrong direction for this issue. My bov is working but just not all the well and loud. Turns out I am only boostin like 5 psi, which i believe is why my bov is not that loud. I thought there was a problem with the turbo because I was told by the guy I bought th car from that it was set a 13psi. I am on a microtech so maybe all my problems can be solved by a tune??? Could there be any other explanation for the problems I am havin?? Tell me what you guys think."""" Anything?????

 

You mean you don't have a boost gauge staring you in the face?

 

No not untill I put one in I didnt!!!

 

Sounds like the wategate is opening...... maybe you should um, adjust it with a boost controller.

 

Well thats what i am asking... do you guys think that by tuning the car my boost issues will be solved or do you think I have a different problem. The only reason I thought I had a bov issue was if it was boosting at 5 psi I was getting real bad surge.... maybe if I get it tuned to run where it should like 13lbs maybe my bov will work harder and have less surge??? Thats why I ask you guys... you have alot more knowledge than I do on this matter.

 

^^^^^^^...Well do you guys think that 5 psi is enough to cause that bad surge or any surge for that matter???

 

LOL I definitely read this thread title as "boy problems."
You all don't even wanna know what went through my head.

 

if you're running a microtech why not take the car to a dyno and have it tuned?the fuel maps might have been set a a certain level and might run too lean when the boost is turned up.might aswell kiss your motor goodbye when you start fiddling around w/ a manual boost controler w/o a wideband or a laptop to see what the base line tune is.or even knowing if the boost guage is even giving you a accurate reading.

 

Sorry to bring up an old thread, but I was wandering if this problem was every solved? I have the exact same problem. I just installed my FMIC and put the bov between the throttle body and intercooler. But my bov does not make any noise whatsoever. I have the bov connected to the UIM and i am pretty sure the hoses are connected right. When I had the TMIC with an HKS bov and it ran fine. And I am using the exact same source line that I used for that HKS and now the bov doesnt work... Any other ideas besides the ones written?

 

Anyone know what can cause this???

 

Bad bov?

Hose collapsing?

improper source?

turbo fubared and not boosting?

You tell us more about what the car is doing and you might get a responce.

 

Its practically the same as the original thread, but I'll let you know step by step what I did:

Well, I got my universal FMIC kit this past friday. I worked on it all weekend. Finished yesterday (tuesday). It cranked up normal, idle was fine, and so i let it warmup so that I can take it out for a spin. I used the exact same vaccum source that I used with the HKS that I had. I even checked to see if I had vaccum, which I do. Anyway, I let it warmup, and I revved it a little bit and didnt hear the BOV at all. I have an RFL bov btw. Anyway, then I revved it higher and nothing. Took it out for a test drive and it drove fine, boosted fine, but NO BOV whatsoever. So, I have no ideas what else it can be. I hooked up to the UIM nipple, and nothing...

Does this help?

 

Without being there for hands on diag, I would say bad BOV. Again that is assuming you have vacuum to it and the turbo is boosting

 

Is there a way to make sure the diaphragm is bad? Cause I can open it when the car is on, but it would die out. And its pretty easy to pull it up. (its an RFL) but when the vaccum is not connected it is definitely harder...

 

hmmmm..... hook a manuel vacuum pump to it and see if it stays open?

 

Yeah, it definitely doesnt open up at all, when I rev it. I just did it. I also sprayed carb+choke cleaner all over my hoses and couplers, etc to see if I can find a leak anywhere, and nothing... So I guess its gotta be the BOV. My question is, how does a BOV get stuck shut? It doesnt vent whatsoever. What would cause this?

 

Anyone? Well I found out that my wastegate was loose, and I tightened it and nothing... Anyone have any other ideas? PLEASE!