Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[socal1200r]

The restrictor is in the vacuum line that controls the BPV diaphragm.
Remove the whole line & replace it with a new piece of vacuum line, it's old & won't flex much anymore.

So I'm going to assume the vacuum line is the smaller rubber hose at the BPV?  Yeah, that sounds like a better idea to just replace the whole line...

[NomakeWan]

The restrictor is in the vacuum line that controls the BPV diaphragm.

Wait, it is? I couldn't feel any restrictor in that tiny little vacuum line. I did end up replacing it anyway because it was stiff and cracked, but are you sure? The elbow from the BPV to the intake has a plastic thingy inside it that sure as hell looks like a restrictor...

[socal1200r]

I don't see how there could be a restrictor INSIDE that vacuum line, it's too small.  Makes more sense for it to be in one of the larger hoses that go to the BPV body.  I'm guessing that small vacuum line is about 2' long, so I'll get a new length of hose for that, and reuse those larger ones on the body. 

It does look like a fairly simple thing to replace, just hope the hoses don't fight me when I try to take them off to swap BPVs.

[socal1200r]

Got a 3' section of Tygon yellow hose to replace the stock rubber vacuum line, that way I'll know that line's been replaced.  Rec'd the Kayser BPV today, so I'm going to attempt to install it tomorrow (Sat).  Hopefully, the combination of new BPV and removing the restrictor will make those darn moo cows go away!

[socal1200r]

Installed the Kayser BPV, and that was an experience.  Removing the stock BPV was easy, and I removed the whole thing, including the two large input/output hoses and smaller vacuum line, so I had the whole thing off.  I found the restrictor in the bend of one of the larger hoses, and there was no way I was going to be able to remove it.  It felt like the hose was formed around that plastic restrictor, so it was a good thing that I had to get new hose anyway.  The yellow Tygon line (5/32 ID x 3') was long enough to replace the stock vacuum line, and fit VERY snug at both ends.  This was good because the stock pinch clamps were too big to work on the much smaller OD of the Tygon line.

Where I ran into problems was with the input/output hoses.  The fittings on the Kayser BPV are much larger, requiring new hoses with a 3/4" ID, so the stock BPV hoses would not fit onto them.  Went to two different auto parts stores, trying to find some hoses to fit over the BPV necks, and ended up finding what I needed at a Napa auto parts store.  I didn't want to make another trip out, so I bought four new hose clamps for the larger diameter hose for the Kayser BPV. 

I ran into a problem when I went to fit the new larger hoses onto the stock BPV metal fittings.  These hoses were just too big, so I was stumped on what to do next.  Luckily for me, the OD of the stock BPV hoses fit inside the new larger hoses, so I used them as a reducer to fit onto the old BPV metal fittings.  One thing I had to do differently was orient the new BPV sideways, because I didn't want to have two 90-degree bends (like the stock BPV) with the larger diameter hose.  So the lower hose goes straight into the bottom of the new BPV, then goes 90-degrees into the upper hose connection.  I figured this should still work, since the BPV operates with pressure and a spring, and should work in just about any orientation, so sideways should work just fine, and so far it has. 

Anyway, if anyone uses one of these Kayser BPVs to replace their stock BPV, just be forewarned you'll need to get larger ID hose to fit, and figure out a way to connect the larger hose to the stock metal fittings.  Using the ends of the stock BPV hoses as reducers worked just fine for me, so that's an option. 

[NomakeWan]

I probably should have posted this before you began your project, but hindsight is 20/20 and to be honest I'd forgotten about its existence: http://www.roadraceengineering.com/323gtxtech/boschbovinstructions.htm

So, is the cow well and truly dead?

[socal1200r]

I probably should have posted this before you began your project, but hindsight is 20/20 and to be honest I'd forgotten about its existence: http://www.roadraceengineering.com/323gtxtech/boschbovinstructions.htm

So, is the cow well and truly dead?

The cow is truly dead, stick a fork in her, she's done!  Only sound we hear now is the occasional "whoosh" of the turbo working, especially when driving thru a tunnel...

[socal1200r]

I probably should have posted this before you began your project, but hindsight is 20/20 and to be honest I'd forgotten about its existence: http://www.roadraceengineering.com/323gtxtech/boschbovinstructions.htm

So, is the cow well and truly dead?

So I made the mistake of doing a search on BOVs, and now have a question about this Kayser BPV.  Can this BPV be turned into a BOV, or is it not up to the task?  From my limited searching, it seems like IF it was up to the task, all I'd have to do is unplug the hose on the Kayser BPV that goes to the front hard pipe and cap it there, put a filter on that end of the BPV, leave the rest of the BPV alone, and that should do it?  But the big question is whether or not the Kayser BPV can be turned into a BOV?  Since it's a stock replacement, I've read that the stock BPVs don't fully close at idle, and won't work as a BOV because of their weaker spring?  But this Kayser BPV is supposed to have a stronger spring, thus its ability to eliminate the "mooing" sound, so maybe it can work as a BOV?

Here's a pic of the Kayser/Bosch BPV I installed:



So IF this BPV could be used as a BOV, I would leave the large upper hose that goes to the intake manifold and the smaller vacuum hose connected; disconnect the larger lower hose and leave it off the BPV "neck"; cap where the other end of that hose went at the hard pipe; and that's it?

[NomakeWan]

Generally it's recommended not to PM someone if you asked the same question in public, but as I replied to your PM before seeing this post, I'll go ahead and answer the question here for everyone's benefit as well.

A BPV is part of the metered air system, and is designed to be open at all times except boost. If you disconnect the output hose, you'll have a massive vacuum leak as air leaks straight out from the side of the intake plenum through the BPV. Under throttle you'll be fine since the BPV will then close and everything will be gravy, but the moment you let off again and it opens, sure you'll get your PSSSH but you'll also go back to leaking air. This will cause your engine to idle like absolute crap, and will also throw a Code 13 as you run much richer than the computer was designed to run the engine.

A BOV has a manually-adjustable spring inside it that forces it shut at idle to try to counteract that leaky idle condition. Set improperly it does the same thing as the BPV and you get a crappy idle, or it's too strong and doesn't open after boosting, causing compressor surge which can be very bad for your turbo. Set correctly a BOV can work, but you'll still run rich and throw that Code 13 as you let off metered air. It will never run as smoothly as the stock BPV system, but if you want that 'pssh' sound that's the trade-off you'll have to make.

[socal1200r]

I probably should have posted this before you began your project, but hindsight is 20/20 and to be honest I'd forgotten about its existence: http://www.roadraceengineering.com/323gtxtech/boschbovinstructions.htm

Now here's something interesting...I went back and read this link, and unless I'm looking at the picture wrong, it would appear that I installed my BPV backwards?!  In the one pic in this link, it shows a picture of the black Bosch/Kayser BPV installed, and it looks like the neck on the side of the BPV is going towards the turbo, and the neck at the bottom of the BPV is going up towards the intake manifold?  I have mine installed the opposite way, and it seems to be working just fine.  From the other link on the first page, where they compared a Forge BOV and a couple of Bosch BPVs, the side neck is for incoming air from the manifold, and the bottom neck is for outgoing air to the turbo or to atmosphere?  If that's correct, then it would seem that the pic from Road Race Engineering shows it installed backwards, or am I just looking at that picture incorrectly?

Here's the pic from the writeup done by RRE:



I'm assuming the bottom of the valve is plumbed up towards the intake manifold, and the side vent goes to the turbo?  This is the exact opposite of how I have mine plumbed.  I got a reply from Mike Welch of RRE, and apparently either way will work.  But what's the RIGHT way to plumb this BPV?

[NomakeWan]

As I posted in the other thread, the short answer is it'll work both ways, and the long answer as to how its operation changes based on orientation is here: http://www.audizine.com/forum/showthread.php/464477-Recommendations-Diverter-Valve?p=7150740&viewfull=1#post7150740

[socal1200r]

Got it..."factory" versus "reversed" orientation.  On a stock engine, either way will work without harming the engine or turbo.  I guess I'd have to actually see how this valve works to figure out which way I want to have mine go.  Since it seems to run fine the way it is, I'll leave it that way for now. 

But just for my own education, when you're looking at the side neck on the valve, it's "blocked" (open?), so I would imagine that area "closes" and opens up to allow excess pressure out the bottom neck based on the vacuum and spring tension?  If that's the case, it would seem to make more sense for the side neck to be the outlet instead of the inlet?   

[socal1200r]

I "reversed" the plumbing I had on this BPV, so the excess boost coming down from the intake manifold goes into the bottom of the valve, then goes out the side to get recirculated.  After reading some other things and watching some videos on YouTube, I think I finally get this.  With the "factory" plumbing, the vacuum line is doing most of the work in pulling the valve closed to let the excess boost go by.  With the "reversed" plumbing, the vacuum line is still pulling on the valve, but the excess boost is also pushing on the valve as well.  This seems to make more sense to me, so I'm going to leave it as reversed.  It idles fine, and my initial impressions are that it seems to boost sooner, harder, and stays on boost longer.  Definite improvement over the "factory" setup I originally had.   

[Btown]

This what I used, no plumbing require and some PTSHHHH too
https://www.ebay.com.au/itm/161516565108