How is your bov set up?

[BruceH]

I've always wondered if I'm doing this right. My ebay special bov came today. It has two springs, one 5psi and one 10psi. Right now it's set up with the 10psi and adjustment screw in three turns. It's still open at idle but not as much as it was with no turns.

I'm tempted to back the screw out and add the 5psi spring. My motor pulls good vacuum, -18in Hg at idle and -22 with closed throttle decel.

If I understand the setup correctly I want the bov to shut at anything above idle. Is this correct? Right now it is open when driving at highway speeds but closes when light to moderate throttle is applied. I know because it can be heard from inside the car. I'm setting this up for a centrifigal supercharger.

 

[Stage1]

Sub'd

 

[Taxman]

Sub'd

 

[retfr8flyr]

Doesn't sound right, with 18 inches at idle and a 10# spring it should be closed at idle without any turns. Try it with both springs and 0 turns and see what it does. Doesn't sound like the springs are truly what they say they are.


Earl

 

[CPRsm]

Shut at idle and above would be nice to keep shit out of the engine preferrably. Closed at idle for a centri is a no no. If it pumps too much the idle can raise. Basically I put it tight to assist the pressure from the top even though it's reeeealy not needed. But loose enough to not get surge. Anything else you deal with. Shifting, engine braking, damn near anything can open it.
If open bothers you you can put a bag/filter of sorts over the BOV. There is a device for the turbo guys that keeps it closed all the time except on release. Ur kinda sol w that unless a closed BOG doesnt affect your idle.

 

[8306gt]

Bruce my vortech valve is always open at idle and while cruising around town and on the highway. It does however close as soon as vac drops from any real acceleration. Mine is mounted about 6 inches below the SC and there is enough air going out anytime the engine is running that there is no issue with it injesting any debris.

 

[michschi]

subbed

 

[CPRsm]

W a blower air will always be coming out like he said. Should clarify. My mind's always think turbo lol

 

[BruceH]

The spring ratings are kind of a mystery. They may reference inches of mercury rather than psi. I have a feeling that they aren't precise numbers.

I've had a centri before and used a mondo configured as a bov. It was open during normal driving. Everything functioned fine the way it was set up but I never knew if it was really correct.

The procharger came with a diaphram controlled butterfly valve that will let air pass through even when closed. It has no adjustment and was open almost all the time except for moderate to heavy throttle. The ebay special bov is directing more boost to the intake based on observations.

I'm asking what is the proper setup because every way I can think of setting it up makes sense at times and I'm thinking myself in circles. Even online guides seem to contridict each other.

I'm going to put the second spring in and see what happens. I'll shoot for open at idle and shut any other time.

Thanks for the responses.

Edit:

The ebay special and proflow side by side.

 

[8306gt]

I'm going to put the second spring in and see what happens. I'll shoot for open at idle and shut any other time.

Open at idle is good, but you don't want it closed at all other time as that kind of defeats the purpose of letting it go to atmosphere. You will be creating unnecessary heat by forcing the air somewhere it isn't needed at light throttle or cruise situations, and most likely tuning issues as there will be more air going into the engine than needed at light throttle or cruise.

 

[Marc s]

Open at idle and under cruise is the correct way to adjust it Bruce. When adjusted properly, it will close at 1/2 of your idle vacuum. So, if you idle at 18", it should close at 9". That's how I always set them up.

 

[JeremyH]

Put the 5psi spring in and call it a day. For a centri setup that seems to work best. If its open at idle/light cruising its okay as long as it snaps shut instantly with revs at idle or moderate throttle. Whats the flow on that unit? Is it going to be up to the task for your setup?

 

[BruceH]

Put the 5psi spring in and call it a day. For a centri setup that seems to work best. If its open at idle/light cruising its okay as long as it snaps shut instantly with revs at idle or moderate throttle. Whats the flow on that unit? Is it going to be up to the task for your setup?

The flow? That's a good question. I'd say the air volume at idle is comparable to what the mondo put out on my other setup which is alot.

It's a 50mm and I have a 38mm adapter on it right now. The procharger piping comes with a 1.5" flange for the proflow. The 50mm bov also came with a weld on flange I can use if needed.

 

[bigray327]

Bruce, why did you move away from the Mondo? If your Mondo shit the bed, why not get a new one?

 

[JeremyH]

Bruce, why did you move away from the Mondo? If your Mondo shit the bed, why not get a new one?

I'm pretty sure that went away when he sold the paxton kit. He has the procharger setup now, or should i say for now.... Bruce is on a quest to have every power adder out there for the 3v. lol

 

[JoshK]

Apparently saving the best for last, turbo!

 

[Flapjack]

Sub'd to get my learn on.

I just posted about my chattery BOV. Might want to check out my thread, as there's some good info in there. Mine's a Tial 38mm. I don't think it has any adjustments.... just different springs you can put in.

Sent from my Galaxy Nexus using Tapatalk 2

 

[JeremyH]

Sub'd to get my learn on.

I just posted about my chattery BOV. Might want to check out my thread, as there's some good info in there. Mine's a Tial 38mm. I don't think it has any adjustments.... just different springs you can put in.

Sent from my Galaxy Nexus using Tapatalk 2

Believe you ment tial 50mm there not 38mm thats the wg . Fluttering gate usualy means too stiff a spring for the vac you have. Which in turns means your likely also getting some compressor surge as well be it a supercharger or turbo setup.

I had an 11psi in my tial bov orignaly which was too stiff a for my vac (18-19) and it wasn't opening like it should so I was getting fluttering/compressor surge. Swapped to a 9psi spring (1/2 my vac) and all is well. No flutter, no surge and the bov springs fully open when letting off the gas and then shuts.

On a blower setup you need to take it a bit further than 1/2 your vac since the blower moves alot of air at idle unlike the turbo which is load based. So for a blower a good rule of thumb is 1/3 of your vac at idle.

 

[BruceH]

Bruce, why did you move away from the Mondo? If your Mondo shit the bed, why not get a new one?

The mondo was great. Like Jeremy said it went with the blow through setup when I sold it. Put frpp cnc heads on and went na for a few months. Now I have a d1sc and I'm working through a few things.

I'm pretty sure that went away when he sold the paxton kit. He has the procharger setup now, or should i say for now.... Bruce is on a quest to have every power adder out there for the 3v. lol

I hope not! I'd like to be able to just leave it alone. If I go turbo it will be twins straight from the factory in an F150.

I changed the signal line out today. For some reason it was 1/8" and tapped into the same feed as the mechanical boost gauge and frps (before someone points it out that reason is me not noticing things I should of). Changed to a 9/32 and teed off of the fuel vapor recirculation line right off of the intake manifold. I'll change the spring out for the 5psi tomorrow to get rid of the flutter.

 

[JeremyH]

Speaking of signal lines, thats something often overlooked I think, I know I never really considered it before. I love the fore boost/vac block I have now. It makes sure nothing is starved for signal and I ran 8an line to it right off the back of the manifold between it and the brake booster which is a perfect spot. I run the my eboost2/boost gauge, frps and bov directly off it now. Instead all the t's off the factory frps line like I had before.