Way to increase spring tension on BOV?

[myke_w]

I am wondering if there is an easy way to increase spring tension in the BOV of a 1.6td to create a 15psi Blow off.. Anybody have any ideas?
Would I be better off just using a boost valve on the wastegate side? If so what brand  is best for our application, and how do other folks configure it?

[ezekiel]

blow off valves don't hold boost, typically.  If you try to dial in 15psi and it leaks, then you can possibly crush the can to get more spring tension, but this is a diesel, you don't REALLY need a BOV at all.

Actual boost control is always done with the wastegate.  A BOV only releases excess boost pressure.

[jtanguay]

yea just block off the bov... get rid of it.  once you hit 15 psi it will stay open until your car reaches about 3-4 psi or so... which is un cool.  A wastegate is more precise, and with a boost controller you can hit 15 psi and sustain it no matter how hard you mash the pedal  it may spike up though... but the wg will intervene

[ezekiel]

what's better for a diesel, if you still want a safety net, is an adjustable pop-off valve.

If you don't want any spiking at all, get, say, a 17psi pop-off valve, if you're shooting for 15psi.  This won't help your turbo over boosting any, but if your engine can't take 17psi, for whatever reason, the pop off will save it.  

But once again, it's a diesel, most of this stuff is for fragile gas engines  they have severe engine knocking they have to tend to  

[saurkraut]

The blow off valve is completely useless on these engines.  If you do see more than 15 lbs. of boost, the engine will not instantly explode.  If you use it as part of your booste controll plan, its garunteed to raise EGT.  Go ahead and search for "my diesel blew up because I ran 1X PSI".  If you don't turn up the fuel, you'll never get there either.

There is a thread somewhere on this board that shows how to disable the blow off valve by removing the adjusting screw, and dropping a short allen screw down the hole.  You put the adjusting screw back in and snug it down.

Here's the link: http://www.vwdiesel.net/phpBB/viewtopic.php?t=2554&highlight=disabling+bov

[myke_w]

My BOV is disabled via the screw method.. I am running about 11 psi max with the wastegate only as of now..

I just wondered if it was wise to only use the BOV instead of a the wastegate, obviously the consensus is no.

It seems I am going to have to go the boost controller to the wastegate route. Cutting the metal line from the cold side to the wastegate is not going to be fun at all.. Can anyone recommend aftermarket fittings that are suited for rubber hose? Does anybody have a recommendation on a cheap boost controller valve?

[Baxter]

VW must have realised the BOV was a fairly lame idea as it didn't make it into use on the AAZ.