yesterday i tried a bov my freind gave me on my stock t2 s4 with top mount . hooked it up and blocked off the hold in the stock intake tube that goes to the turbo . the bov worked fine but did not hold idle. i also hooked up the vacuum line to bov. so i dont get how many of you put bov on your cars cause i cant find a good write up .

 

you probably have a vacuum leak somewhere, its possible the bov could have a leak. is it a knock off?

 

Stupid question, but did you adjust the valve properly?

 

There has to be an air leak somewhere.

 

hmm my only guess is that the bov was bad . can i try the stock one ? as in like pull it off and block the hole in the intake pipe and see if it holds idle?

edit i forgot wat brand it was , came off my freinds vw .

 

Bad bov. In my experience, when it comes to bov's, get a name brand one. Cover your hand over its outlet, and odds are the idle will come back.

 

stock blow off goes back into the air box, if you dont cap or plug the hole on the air box, your car wont idle, had mine stuffed with a rag in the past and it fell out while i was driving, when i came to a stop, the car stalled.

 

You can't vent the stock BOV to atmosphere. As it's not a BOV, it's a bypass valve. There is a difference.

 

ricer

 

Just be lucky you didn't suck it up and have it take out your turbo.



Is it really that hard to go to the ace, or home depot or something and get a simple pipe plug to put in the hole, then use a hose clamp over the rubber to hold the plug in? You'd be surprised how many turbo pieces I can buy from a place like home depot. My favorite is their thick rubber pvc couplings that are meant to hold up to 40 psi. They fit right on my intercooler piping and hold better than any other couplings I've tried in the past, oh and they're only a couple bucks.


OP, just buy a real atmospheric BOV like a Blitz or an HKS and call it a day. Or, reroute your stock >BAV< into it's stock location and live with it. A stock turbo setup doesn't really make the loud BOV sound I think you're looking for.

 

If your BAV was already working, why install the BOV? For the sound?

 

To add, a BOV on a stock setup won't make much noise. Probably just sound like someone letting the air out of a bike tire...

 

lol yeah . i wanted it for the sound and a lil better look under the hood . but i guess ill try it again and see if the bov is leaking

 

im not venting stock, im running a turboxs bov. was just tring to mention that you need to block the hole once you go aftermarket. the rag was to big to go through the wrong way and it was only for a day or two. i used the cap piece off a nos energy drink bottle and hot glued it on, it fits nice and snug.

also bov on stock sound decent actualy. better than no sound at all, that just seems wrong.

 

yeah the car is wayy to quiet for me stock exhuast and all , just finished fixing a boost leak i had and stuff . car is all original 92k

 

It's been a while since I had a stock airbox, but isn't the AFM after the airbox? If that's the case it wouldn't matter if you stuffed a rag in that hole or left it open as the air would be metered by the afm either way. The only hole that removing the stock BAV creates is the one on the TID iirc THAT should be plugged.

BOV's are NOT rocket science, mount it, find a proper vac/boost source and hook up the reference line. Done.

Even at stock boost a proper BOV will make a noticeable sound. Hell, above stock boost even the stock unit (recirculated) can be heard from the cabin with a reasonable exhaust.

 

The hole for the stock bypass valve is in the TID *after* the AFM. Hence why using an atmospherically vented BOV on a vehicle with a stock ECU isn't the most ideal situation.

 

i've seen alot of blow off valves leak, even the best name brand units.

it's just not a good idea for a stock car if you want to keep it running well. even for performance builds i consider blow off valves an aesthetic mod, it adds zero performance improvement and is a "look at me" mod.

 

You can still recirculate that BOV.

It is SIMPLE. Google image: "recirculating BOV". Even when displayed on other cars, it should still be pretty understandable.

This is a pretty good example of a recirculated BOV: http://www.enginebasics.com/Advanced...circulated.jpg

 

what's the point of recirculating an aftermarket blow off valve to do what the original bypass valve did?

 

There is no point... I am just stating that it must be recirculated on a stock set-up. It seems that no one else brought up the fact that this BOV must simply be recirculated on the stock set-up. OP, this probably has something to do with your shitty idle... You'd be best off using the stock bypass valve.