Need a piece of hose

[bootlegdsm]

Working on my first VW. It's an 85 Jetta Turbo Diesel I picked up a couple of weeks ago. I'm trying to iron the wrinkles out of it. So far new rear shocks, glow plugs, and will need some rust repair, but my issue right now is a piece of hose. Someone rigged up a piece of hose off the BOV back into the intake. It's obviously not the stock piece, and is bent horribly, so that the BOV isn't able to sufficiently let the pressure off like it should. I would like to know if that piece is able to be had anywhere other than a junk yard?

[bootlegdsm]

Ok, well.. how about this:

Can you do away with the return hose, block the hole in the intake pipe, and vent the BOV to the atmosphere without any negative consequences?

[Vincent Waldon]

Actually if you do a bit of searching on "BOV" you'll discover that it's not required and most people simply delete 'em and be done with it. 

[bootlegdsm]

I did a quick search, but I didn't see much. I'm new to diesels, but not to turbo's. It seems counter-intuitive to delete a BOV. I will do some searching and see what I can come up with. Thanks

[truckinwagen]

it really is not a BOV, but an overboost protection valve.

since a diesel does not have a throttle plate, there are no dangerous spikes in boost pressure(that a BOV protects against)

the overboost valve is there to keep boost from getting too high(haha, like that could happen) if the wastegate fails, and since these cars did not have boost gauges, it is hard to tell if the boost is getting too high by yourself.

it is simply a spring loaded valve that opens around 10-11PSI all of a sudden.

if you have a boost gauge you can see if the wastegate fails and boosts too much, and simply get out of the throttle, making the overboost valve unnecessary, and a pain if you want to boost more than 10PSI(and who here does not?)

-Owen

[Vincent Waldon]

I'm new to diesels, but not to turbo's.

Yup... in this case the differences between gasser turbo plumbing and diesel turbo plumbing are a factor.

it really is not a BOV, but an overboost protection valve.

since a diesel does not have a throttle plate, there are no dangerous spikes in boost pressure(that a BOV protects against)

That's a really good way to think of it... not as a BOV that's needed all the time but as overboost protection which on our little turbos is pretty much vestigial... VW themselves deleted the valve by the mid-1990s.

There's lots of chatter about this... I get 40 pages of threads when I search for "BOV"  

This one at the top of the list discusses their merits:
http://www.vwdiesel.net/forum/index.php?topic=5552.0

This one discusses BOVs vs. pop-off valves;
http://www.vwdiesel.net/forum/index.php?topic=27541.0

You can plug it with a chunk of heater hose:
http://www.vwdiesel.net/forum/index.php?topic=781.0

You can also cut down a strut cap:
http://www.vwdiesel.net/forum/index.php?topic=16556.0

Giles had an aluminum disk machined up:
http://www.vwdiesel.net/forum/index.php?topic=18289.0

[bootlegdsm]

Ok, now it makes a little more sense. So it sounds like the "bov" is actually a secondary fail-safe device that serves no purpose other than to be there if the wastegate stays closed. Easy enough. So what happens in these engines when you run too much boost, say a spike, or too much air vs fuel? (aside from pressure related damage) Would it just stall out the engine like it's starved for fuel? Sorry for the newb stuff, I'm learning as I go. I just need a few puzzle pieces to start and I'll figure the rest out easy enough.

I'm sure I'll be playing with the turbo eventually, but for now, I'm doing all the maintenance I can and making sure it's in good long-term drivable condition. My DSM is under major construction right now (or perpetually really) so I need something I can rely on.

[theman53]

I really don't think there is such thing as too much boost for these. Maybe over 30??? I am set at 25psi with the k24 not intercooled right now, but it is highs of 30F since I have done it. I will intercool, but I think 25psi is a safe upper limit for the turbo and the block. I don't hit it every time I boost either, so that my help.

[745 turbogreasel]

... So what happens in these engines when you run too much boost, say a spike,...

Nothing.

But you will for sure notice how poorly it runs if/when that blasted valve pops open!
Pretty much it just feels like you stepped off the gas for a few long seconds till the spring re-seats it.

[bootlegdsm]

Definitely different than what I'm used to. Thanks for all the replies...I have a little more research to do yet. I'm so glad the registrations were opened back up:P

[R.O.R-2.0]

I really don't think there is such thing as too much boost for these. Maybe over 30??? I am set at 25psi with the k24 not intercooled right now, but it is highs of 30F since I have done it. I will intercool, but I think 25psi is a safe upper limit for the turbo and the block. I don't hit it every time I boost either, so that my help.

you can blow the head off one with enough boost..

i had to take my 1.5D up to 40+ psi to lose the head..

[Baron VonZeppelin]

Pretty much it just feels like you stepped off the gas for a few long seconds till the spring re-seats it.

Precise description there, 745.

My first one (TD) was popping open at about 7-8psi.
Felt just like that too.

Libby's method with spacer is good and might produce more allowable boost than just tightening the adjustment screw all the way in/down - on its own.

The last 2 i've worked on i just tightened down the screw and they boost to 11-12 psi now.