Which BOV to purchase?

[#391]

My BOV (diverter valve) is 19 years old, so I figure it's time to be replaced with something new.

What is the best valve to get, and where? If it matters, my engine/turbo/wastegate, etc. are all stock.

Thanks!

[CJFusco]

I don't think there's any reason to replace the stock unit unless it's failing.

I bought a reworked Bosch BOV off eBay. It has all the stock dimensions, but is built out of aluminum instead of plastic.

[#391]

How do I know if it's failing? I seem to recall something about sucking through the nipple on the top (settle down boys : ), and that you shouldn't be able to pull any air through? Is that correct? It just doesn't seem like a very scientific method of determining whether or not it is good.

I guess I just figured after 19 years it would be ready for replacement. Maybe that's not the case, as long as I can effectively test it.

[nynor]

^that's how you test it. i'd probably replace it with something billet.

[soxnail]

Yup no air flow through it under normal (standard atmospheric) conditions. If you want to test it fully then:
1). Pull it off the car.
2). attach an air source to the side that goes to the hard pipe from the intercooler. (be able to provide 10 psi)
3). No air should go through the valve. If it does then the valve is barfed.
4). if it passes 3 above, then with pressure on the inlet as in step 3 apply vacuum to the nipple only a couple of inches is enough. The valve should allow the pressure on its inlet to be dumped to the outlet (the side that goes to the "J" pipe AKA THE "Alien"). If it does not then the valve is barfed.
Good luck Sox

[#391]

Originally posted by nynor
^that's how you test it. i'd probably replace it with something billet.

Is there a reason to get a billet valve (other than my fixation with shiny parts? )

[nynor]

i *think* they are rebuildable and shiny and more durable

[mfloren]

the stock piece bleeds boost and helps cause lag.

the billet ones pretty much stop this effect. something about using metal vs rubber.

also, the stock ones are only good for about 5 years.
I just picked up a 97 951 with 110k miles for 3k. the owner thought it was screwed up. but 400$ later, including tires, its running like a champ.

the bov is a big problem. id upgrade this and the waste gate. on any stock 951.

[Porschefile]

What Mfloren said. Seriously though, the stock plastic DV's wear out pretty easily. Not to mention, at elevated boost levels like 14-18psi, they can wear out pretty darn quickly to the point where they don't stay shut 100% and will cause more lag. The stock type metal DV's are okay but there is better stuff out there. Forge DV/BOV's are pretty decent too.

[#391]

Just bought a billet one, thanks for all the info guys.

I stuck a short length of vac line on the stock DV and sucked. I got lungs full of fuel-tainted air...so I think I was sucking air through the DV (kinda hard to tell though.)

[mfloren]

I purchased a billet one off of e-bay, 50$, and it works like a champ. no name brand but hey. its only air. right?

[#391]

Originally posted by mfloren
I purchased a billet one off of e-bay, 50$, and it works like a champ. no name brand but hey. its only air. right?

Yeah, that's what I paid. I wonder if it's the same one? I'm glad to hear it works well, thanks!

[nize]

evolution motorsports billet bov. rebuildable with lifetime warranty. $50 from imagine auto;
http://www.imagineauto.com/

[nize]

update: imagineauto has sadly gone out of business.

i've found this same bov elsewhere but the price has gone up to $130;
http://www.aptuning.com/products.php?productid=423

also available directly from evolution motorsports for $130;
http://tinyurl.com/kljqt6

evolution motorsports is here;
http://www.evoms.com

[nize]

here is a forge BOV for $125 in silver, part FMDV007PA;
http://www.velocityfactor.net/wwwroot/Scripts/prodView.asp?idproduct=676

$135 for a black one;
http://www.mjm********.com/catalog/product_info.php?products_id=1294

[trivgar]

I have a samco recirc much like the forge ones. Totally sold on it. Great unit.

[carlege]

Originally Posted by nize

evolution motorsports billet bov. rebuildable with lifetime warranty. $50 from imagine auto;
http://www.imagineauto.com/

will the company honor the warrenty with the place that sold it out of business?

[carlege]

http://www.summitracing.com/parts/SAM-DVA2P001BLK/

is this the samco you mentioned? ($102) Looks like a good one

[trivgar]

<a href="http://www.summitracing.com/parts/SAM-DVA2P001BLK/" target="_blank">http://www.summitracing.com/parts/SAM-DVA2P001BLK/</a><br>
<br>
is this the samco you mentioned? ($102) Looks like a good one

Nope. That's atmospheric. This is mine.http://www.optionsauto.com/prodinfo.asp?number=SAM-DVR-1P-001-SL

[running_cold924]

can you still use the one from summit? it just dumps to the atmosphere right?