| BOV only releases at high psi & high rpm... - Click HERE for Original Thread |
| AdamP |
I just installed a Blitz SS BOV on my S13.
I have a few questions regarding the tuning.
I rev the car just standing under the hood and looking down into the BOV.
Loose setting:
Mild revving, the is a deep rattlesnake-like whoosing in the pipe. The blow off valve piston is not moving at all.
Medium revving results in some more whooshing (surge I believe) and the BOV is still not not moving.
Some harder revving releases the blow off valve but only a little bit.
Medium setting:
Mild reving - the whooshing in the pipe is more of a continuous sound, the BOV piston isn't moving here.
Medium revving results in a louder whooshing sound with a bit of resonance inside. BOV piston isn't moving.
Hard revving opens up the valve. Loud.
I've adjusted the screw from very long (loose) to very short (tight) and I have no idea what the correct setting is.
Shouldn't be BOV piston open up a little bit even if it's making like 2-3psi boost at the time?
Could there not be enough vacuum? On this particular vac line I have the fuel pressure regulator and the BOV. On the SR20DET how many vacuum lines do I have and which ones can I use?
When driving (under load):
When I rev the car up hard under load in 1st gear up to 6000RPM+ the BOV opens up and is loud.
Continuing onwards, there is about 1s lag (foot to the floor) and in 2nd gear. At 6000RPM+ the BOV is barely releasing any air. I am running full boost (7psi) because I am WOT and I can definately hear it spooled.
From third gear, WOT and letting off there is no BOV sound. I just hear a deep whoosh. Any ideas?
My ARC Super BOV also behaved in the same way so I think it may be a weak vacuum.
I am going to get the recirculation kit as soon as I can find one for this BOV but for now I want to know why it isn't opening at very small psi? Maybe if anybody has any vacuum hoses kicking around I might pick those up to replace a few of my lines. |
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| ChromeDragon |
Testing the BOV with the car in neutral is pointless ... unless it's an SRT4. Those things set off the blow off valve when you turn the engine over.
Was there no manual with the BOV? |
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| AdamP |
| Manual? No, I bought the BOV itself. I mean all you have is a flange to mount, vac line to connect and a screw to adjust. |
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| baker_jeff |
| It should go off if there is boost in the system. It's possible you have a leak somewhere, maybe a problem with the BOV? |
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| JustinL |
| Check your vacuum level. IMHO the proper setting for a BOV is that it should be open at any vacuum above the idle level. If you have a vacuum leak though it may not have enough pull to overcome the spring tension in the valve. Another thought is to change out the spring if you can open the valve up. |
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| crazyrx7 |
quote:
Originally posted by ChromeDragon
Testing the BOV with the car in neutral is pointless ... unless it's an SRT4. Those things set off the blow off valve when you turn the engine over.
Was there no manual with the BOV?
Thats the funniest thing I've heard in a while:lol: .
R.K. |
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| DSM |
quote:
Originally posted by JustinL
Check your vacuum level. IMHO the proper setting for a BOV is that it should be open at any vacuum above the idle level. If you have a vacuum leak though it may not have enough pull to overcome the spring tension in the valve. Another thought is to change out the spring if you can open the valve up.
Why would you want your BOV to open under vacume? |
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| JustinL |
quote:
Originally posted by DSM
Why would you want your BOV to open under vacume?
When you snap the throttle plate shut on the manifold, the engine is still pulling air. This creates a vacuum or suction that opens the BOV and lets the boost escape instead of slamming into the throttle plate and stacking up.
A BOV should only open under manifold vacuum conditions i.e., throttle plate closed; if your manifold is seeing boost, then the throttle plate is open and you want that BOV closed. |
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| Soulfly |
I didn't read the thread... But...
EDIT: .. THIS IS ONLY FOR VEHICLES THAT USE A MAP (Manifold Absolute Pressure) Sensor!
Your BOV SHOULD be Open at idle.. or.. with more than 10hg vaccum... around -7 and more.. it should be open.. around -3 to -5 it should be closing or closed... if Its not.. tighten it up more....
This will have it ALWAYS open on throttle Lift.. Which is what you want..
If it's too tight.. and it's closed at idle.. or -10 to -15 or so... then It won't Blow off Properly Thus Giving you some Cool Compressor surge.. or.. a surging BOV.. Or both..
Hope that makes sence. Just drive around .. get up to temperature..
then adjust it... so it's open at idle.. ;)
I did this with mine.. and Haven't had a problem since.. and it got louder aswell.. :thumbup: :thumbup: |
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| impact |
i had the same bov on my old rx7. and it did the same thing.
so i took it a part cleaned it and re lubed it.
after that it seemed to work a lot better. |
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| Flip |
| Your BOV definately should not be open at idle. It opens between shifts when the vaccum combined with the pressurized charge pipe causes it to open. If your BOV is opening at idle, you have problems, especially if you're venting it to the atmosphere sucking in unfiltered air, or if you are running a MAS system and the air it brings in is unmetered. |
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| Soulfly |
quote:
Originally posted by Flip
Your BOV definately should not be open at idle. It opens between shifts when the vaccum combined with the pressurized charge pipe causes it to open. If your BOV is opening at idle, you have problems, especially if you're venting it to the atmosphere sucking in unfiltered air, or if you are running a MAS system and the air it brings in is unmetered.
Some people have different opinions.... |
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| ylfcm |
quote:
Originally posted by Flip
Your BOV definately should not be open at idle. It opens between shifts when the vaccum combined with the pressurized charge pipe causes it to open. If your BOV is opening at idle, you have problems, especially if you're venting it to the atmosphere sucking in unfiltered air, or if you are running a MAS system and the air it brings in is unmetered.
i am on side with you
my car would never idle if the bov was open under any conditions but letting off the gas. |
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| Soulfly |
Honda = MAP
others... MAF...
MAP FTW! :P
anyway.. I'm not so concerned about 'Unfiltered air'.. because it's not sucking much air... and the chance of it sucking in anything harmful.. is VERY SLIM. (In my setup)
And also.. Yeah.. if you have a MAF.. don't pay attention to my above posts... because it will have an adverse affect on your car.
I forgot about the MAF's.. Sorry boys... :dunno: |
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