Thinking about adding a BOV......Is it Worth It?

[HotRodV6]

I got to thinking that most of your factoru turbo cars have some kind of BOV or bypass valve to relieve the pressure when you get off the gas, but the SyTY does not have anything like that and i have always wondred why?

I want to add the aluminum hard pipe between my turbo and IC and was thinking it would be a good idea to add in a BOV, but i havent seen many post talking abou this, so do these not do any good on our trucks? With a basically stock motor, but with build plans down the road will the addition of a BOV make any differeance? Other than the cool sound they make?

 

[BigBadSmoosh]

Re: Thinking about adding a BOV......Is it Worth It?

sure, add on.. it can't hurt..

if you let off the gas on a sy/ty you can hear the air in the intake box "flutter" sounds like a bird is stuck under your hood.

 

[MikeRenz]

Re: Thinking about adding a BOV......Is it Worth It?

it might gain you another 10,000 miles overtop of the 500,000 miles the turbo should last. Its not really worthwhile imo, and is just asking for boost leakage.

 

[MikeRenz]

Re: Thinking about adding a BOV......Is it Worth It?

if you let off the gas on a sy/ty you can hear the air in the intake box "flutter" sounds like a bird is stuck under your hood.

yes its flutter, but its not in the intake box.

I'm pretty sure the flutter sound is the turbo trying to push air into your closed throttle body....but not being able to.

So you let off the gas, rpms start dropping....and as the turbo starts spinning a bit more slowly, the pressure its building against the closed throttle body makes the turbo balk, or stutter. Thats what you're hearing.

Adding a BOV doesn't fully get rid of the turbo flutter. At least i can still hear it on the couple trucks i've been in that had them. Helps, but not completely. Again...i'd be more worried about the turbo eating plastic/rock, and that it was getting clean oil/water before i worried about the flutter.

 

[Windedv6]

Re: Thinking about adding a BOV......Is it Worth It?

I never had one on any of my builds and would agree with Mike...until this past year when I was running 30# of boost. I started blowing off lines and hoses. After screwing with this several times and having my motor pop and bang after something comes loose...I put on a BOV. Solved the problem.

John

 

[HotRodV6]

Re: Thinking about adding a BOV......Is it Worth It?

Guess ill spend the 200 bucks on somethin else for the time being and worry about it being a needed item down the road.

Thanks for the great input.

And yes i can hear the flutter everytime i let off the gas.

 

[It's just a six]

Re: Thinking about adding a BOV......Is it Worth It?

If you look atfactory BOV's they do not vent to the atmosphere... they recurculate it back into the intake plumbing, on my wife's Jetta it recirculates just before the turbo inlet.
It would be better to recirculate it before the intercooler, so it will have chance to cool it down again.
With a BOV that vents to the atmosphere, all your boost pressure is lost & it will take longer to build up boost again, the factories I think have the right set-up... they just need to replumb the vented excess boost pressure back to before the intercooler. :2cents: :tup: :tdown:

 

[SyTyJedi]

Re: Thinking about adding a BOV......Is it Worth It?

If you look atfactory BOV's they do not vent to the atmosphere... they recurculate it back into the intake plumbing, on my wife's Jetta it recirculates just before the turbo inlet.
It would be better to recirculate it before the intercooler, so it will have chance to cool it down again.
With a BOV that vents to the atmosphere, all your boost pressure is lost & it will take longer to build up boost again, the factories I think have the right set-up... they just need to replumb the vented excess boost pressure back to before the intercooler. :2cents: :tup: :tdown:

This is only on MAF equipped cars to prevent a stumble from running too rich via venting the air to atmosphere. You don't have to worry about losing boost when changing gears in an automatic either since there is always a load on the motor. Running a BOV actually helps keep the turbo wheel speeds up when changing gears (manual) or getting in and out of the throttle (auto) since the air is not going back thru the turbo, against the direction that the wheel is spinning and slowing it down.

I have 2 HKS SSQ BOVs and I wouldn't do another build w/o a BOV. It's only 200 bucks including flange, not going to make or break the future of the truck.

 

[bdydrpds10]

Re: Thinking about adding a BOV......Is it Worth It?

If you look atfactory BOV's they do not vent to the atmosphere... they recurculate it back into the intake plumbing, on my wife's Jetta it recirculates just before the turbo inlet.

Yes.. but it is called a Diverter Valve.

 

[sy#2921]

Re: Thinking about adding a BOV......Is it Worth It?

Diverter valve, bypass valve and blow off valves are all the same in operation. blow off are normally know for venting to air and both diverter and bypass normally vent back preturbo but post maf. BOV are bad for cars with a maf due to the fact that air was read by it already and will cause a rich condition as stated above.

The function of all that everyone is missing is the surge factor stated as "flutter". It would help to have a BOV but main thing it will do on an auto like ours is turbo life. Instead of having the throttle body close and have boost build and nowhere to go it releases excess pressure so it doesnt try to actually spin the turbo backwards. So you are saving the turbo from uneeded forces it doesnt like. Now i did say auto earlier since auto cars are less harsh on turbos then manuals because of a few reasons in my opinion. Manuals benefit more on a bypass system of some sort because it helps keep the turbo spooled inbetween shifts because the air isnt backing up on itself. Granted stock syty's have gone tons of miles with no bypass system but a lot of them were driven nicely but even the ones that were didnt have too many problems. But we are talking most of the time in high performance apps. but no matter what you are doing it is a good idea to have one on a vehicle with any form of forced induction.

 

[SY2932]

Re: Thinking about adding a BOV......Is it Worth It?

This subject has been discussed several times on here. Consider that the stock turbo spins at 130,000 to 140,000 RPM's under full boost, that's 2166 to 2333 revolutions per second. Now, imagine that compressor wheel fully spooled producing 14.7 psi and then the throttle blades close. Where is that pressure going to go? The answer is, it gets "backwashed" through where it came from. I know of one member on here who actually had the nut that held the compressor wheel (big after market turbo) spin off as a result of the rapid deceleration because of this...

I took quite a bit of flak from my buds when I installed my HKS BOV four years ago. The only time that I have gotten flutter with mine is when it is very cool outside. I still have the factory intercooler so, the volume that it has to "depressurize" is relatively short. On trucks with air to air intercoolers, they seem to get quite a bit more flutter. I'm convinced that is is due to the additional volume of the piping that causes this. You could adjust the BOV to open quicker but, you may experience boost leaks at higher pressure doing so. Is a BOV necessary on our trucks? NO. Could it possibly aid in the longevity of the turbo? YES. Basically it comes down to personal choice. My truck will always have one as long as I own it.

 

[wantingasy]

Re: Thinking about adding a BOV......Is it Worth It?

What's the sound difference with a BOV? Is it a noticeable sound?

 

[wantingasy]

Re: Thinking about adding a BOV......Is it Worth It?

Anyone?

 

[cloneman315]

Re: Thinking about adding a BOV......Is it Worth It?

they do sound kool i had one on my old build, but i will not use one on my new build,u really dont need it i dont think. if u ease of the gas u will have very little fluter its just another thing to mess up.

 

[It's just a six]

Re: Thinking about adding a BOV......Is it Worth It?

When I talked to Anthony , the owner of Greedspeed which works along with Neuspeed, they both do not want to vent the excess boost pressure to the atmospere, they say the best thing is what the stock factory VW's did , reroute it back into the intercooler plumbing :2cents: :rotf:

 

[cloneman315]

Re: Thinking about adding a BOV......Is it Worth It?

that might be because they are mass air cars they are working with?And it needs to go back into the motor

 

[It's just a six]

Re: Thinking about adding a BOV......Is it Worth It?

:roll: That's true....but what about all those rice burners...? Do they use air mass systems? Hondas, Mitsubhi, Toyyotas??? and so on?? I don't follow those too much.

 

[cloneman315]

Re: Thinking about adding a BOV......Is it Worth It?

yeah most of the newer ones do ,but ricers dont care its all about the bling bling and shit right

 

[It's just a six]

Re: Thinking about adding a BOV......Is it Worth It?

Fo sho :tdown:

 

[MikeRenz]

Re: Thinking about adding a BOV......Is it Worth It?

What's the sound difference with a BOV? Is it a noticeable sound?

um...you here a "pssshhhht" sound when you let off the throttle...or during shifts on a manual tranny. Just a quick release of compressed air. Its very noticeable. The motor will not sound any different.