erevos

Greetings from Greece..

I own a Turbo II FC with no mods.

I just installed A Blitz BOV the one with the trumpet/hornet.

here is a url from ebay with the bov:

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2459396972

This Bov is supposed to be loud (one of the loudest in the market) but mine is very quiet!!!!

It has a screw on the top that i think is adjusting the sound.The guy who installed it unscrew this screw almost complete but i barely can hear a sound that sounds like a whistle.

Can anyone tell me why this bov is so quiet on my car???
What should i do to make it more loud????

I thank you in advance.

RETed

Where is the vacuum hose going to?


-Ted

enrique

they aren't that loud like a hks. adjusting the screw will help performance wise and sound wise.

erevos

RETed I didnt understand what u mean....

The Bov came with a flange for the FC and it replaced the stock one.
When it was installed i covered the hole right after the airfilter box that was left uncovered with a screw.

Also with the Blitz bov installed, my boost meter is higher than normal when the car idles.

RETed

All BOV's are trigger via a vacuum hose attached at the top of the BOV itself (typically).

Where is your hose going to?
Do you even have this hose installed???



-Ted

erevos

Yes of course.
On the top of the Bov there is a small <<nipple>> for the vacuum and i installed that.The stock bov was also connected to that little hose.

RETed

Ok, so you did use the old vacuum hose that runs back to the intake manifold right under the BAC valve, right?


-Ted

Aaron Cake

iTrader: (1)

The fact that your boost guage now reads less vacuum indicates that you may have a vacuum leak somewhere. Vacuum hose connected to the BOV? Is it cracked, brittle, etc?

erevos

I think that you are probably right...There are not obvious vacuum leaks but i will check.
Any ideas where to look ot how to find the leaks?

All hoses seem ok....

fc3seeker

listen for hissing sounds is the only advice I can think of.

SpeedFreak03

Yea sounds like a vacuum leak check for hissing sounds. Good luck!

erevos

After two weeks of driving my bov is becoming more loud....maybe the spring was stuck or something like that....

RETed

Oh crap, duh...Blitz BOV.

If you take it apart, you'll notice that there's gouge marks on the bore due to the piston cocking sideways.&nbsp; The piston will jam and not open at all.



-Ted

erevos

Ok...this is an ancient topic but finally my Blitz BOV sounds like a BLitz BOV!!!
The sollution came with the installation of a TID and a HKS air intake.
Now i can hear my BOV loud and clear!!!!
Case closed..

fcs4manila

Where is the stock BOV located in an 87 turbo ii?
I'm kinda confused about something.
Is the wastegate like a bov? or are those things separate from each other?

I'm also thinking about getting a better BOV but I don't know where to begin.
Thanks =]

Bamato

iTrader: (6)

The stock turbo system uses a bypass valve. It's attached to the turbo inlet duct coming off the airbox. And the other end of it connects to the metal charge pipe between the intercooler and turbo.

A waste gate controls the flow of exhaust gasses on the turbo hot-side. They prevent over-boost/boost creep by bypassing the turbine wheel and re-route exhaust gasses directly into the exhaust. A BOV controls the amount of air pressure in the inter-cooler. When the throttle plates slam shut during gear shifts, that pressure needs to go somewhere (as the turbo is still producing boost) so it vents it back into the turbo inlet duct (recirculated system) to prevent the throttle plates from taco-ing. So no, a BOV and a waste gate are not the same thing.

As for adding an atmospherically vented BOV, it isn't recommended on a stock setup for a few reasons. First and foremost, your ECU expects the air to be recirculated into the intake system (post AFM). Without the air, it doesn't know to compensate by decreasing the amount of fuel it injects. Therefore causing a rich condition and other side effects (backfiring, decreased CAT life).

Keep in mind, the stock boost levels are ~5 psi. So you aren't going to get much of a "whoosh" noise anyway.

fcs4manila

Thanks for the reply.
The reason I'm thinking about a new BOV is because I have a modified intake and i'll be getting the cat-back exhaust system later. I'm just concerned for the boost creep.
So as for now, should I just open up the wastegate more? Thank you so much.

Bamato

iTrader: (6)

Modified intake and exhaust or not, my above statement still applies. Until you upgrade to a standalone EMS, the ECU will always expect recirc air post AFM. And as I explained above, a BOV is going to do nothing to prevent boost creep.

As for the boost creep, I'm not sure you'll get a ton with just a cat-back. I can't speak from experience though, as I went full exhaust. However, better safe then sorry, seeing as you're most likely still running a stock S4 turbo, you'll want to port the waste gate if you haven't already done so.

It seems to me that you may still be a little misguided on the differences between a waste gate and a BOV. Although they look very similar, remember, they are two separate control systems on a turbocharged engine. The BOV controls the flow of pressurized intake air, and the waste gate bleeds off excess exhaust gasses. It's the waste gate you need to be concerned with to prevent boost creep.

I'm sure you've done some reading on the forums already on modified exhaust systems. It's the best way to get power on a rotary without major upgrades to the turbo and housings. But be sure to have all your concerns ironed out first. Like I said, I'm not sure how much more flow you should expect out of a cat back, but if it changes enough, you'll need ways to compensate fuel as well. Injectors, Rtek chips or FCD's, etc all have to thought of before you lean the engine out mistakenly. And I'm sure everyone will agree, invest in a Wideband O2 *system*. They are invaluable, and necessary anytime you make adjustments to the fuel control system.