BOV opens up as soon as I start the car
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From: Summerville, SC
BOV opens up as soon as I start the car I've got a JGSPT BOV on my twin turbo kit that I got from 1fastbird. I finally got it to start up and worked through a few other issues and now I find this.
As soon as the car cranks up it slams open. I have it t'd into the wastegates that are fed up to my vacuum block.
I'm trying to get a new oring and see if that helps. Any other ideas?
As soon as the car cranks up it slams open. I have it t'd into the wastegates that are fed up to my vacuum block.
I'm trying to get a new oring and see if that helps. Any other ideas?
Wastegate should have reference from the compressor cover (never sees vacuum) and the BOV should have reference to the intake manifold. Put a heavier spring in the BOV to fix your problem.
The BOV is open at idle because you are pulling vaccum. Its supposed to work like this. When you put load on the engine the valve will close and you will begin to build boost. Like stated the BOV should be referenced at the manifold and the wastegate referenced on the compressor side.
good advise, how much vac do you have at idle? most BOV manufactures have a guide that will tell you what spring you need depending on your vacuum.
you will get it, just keep asking questions.
you will get it, just keep asking questions.
Thread Starter
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From: Summerville, SC
15-20" at idle.
I just noticed that the BOV only has one port. Every one that I've seen or owned had two. I disconnected it and it stayed shut. It's definitely not supposed to be open. It's a huge vacuum/boost leak.
With the vacuum hose connected, it sucks that biatch right open. What size spring should I be running in it and does anyone know where to get them and the o-ring replacement.
I just noticed that the BOV only has one port. Every one that I've seen or owned had two. I disconnected it and it stayed shut. It's definitely not supposed to be open. It's a huge vacuum/boost leak.
With the vacuum hose connected, it sucks that biatch right open. What size spring should I be running in it and does anyone know where to get them and the o-ring replacement.
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We are talking about a BOV correct? It is supposed to be open to release the pressure. It is working properly. A BOV only has one port to be hooked to a vaccum port. When a load is placed on the engine IE driving, the valve will close.
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Most of them are open at idle/part throttle. As soon as you go WOT and the turbo starts to spool, it'll slam shut until you let off again.
No they are not supposed to be open at idle you have too much vacuum for the rated spring. The guy you bought it from probably had a bigger cam that caused a lower idle vacuum. Say you idle at 50 kpa, you want a spring that opens below 40 kpa or so.
Rod, does it shut when you give some gas? It hung open when it idled for me but never was an issue when I got into the gas.
It will slam shut when you give it some throttle. Won't hurt anything the way it is since you don't build boost at idle
It will slam shut when you give it some throttle. Won't hurt anything the way it is since you don't build boost at idle
Thread Starter
11 Second Club
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From: Summerville, SC
It only closes slightly if I blip the throttle. It's a huge f'n hole though. I definitely don't like that. It's pretty loud as well. I thought that my alternator was going out and then I seen that hanging wide open and shut it. The "noise" went away.
I have 2 springs in my jgs BOV on the turbo rat to keep it closed at idle. At boost & the throttle blade closes, you have lets say 15 psi pushing on one side of the BOV & who knows how much vacuum pulling from the intake mani, it flies open in a hurry even with some pretty stiff springs in there.
I had 3 springs that came with my jgs, I used the minum combo that kept the BOV closed at highest vacuum to keep dirt/unfiltered air out.
I had 3 springs that came with my jgs, I used the minum combo that kept the BOV closed at highest vacuum to keep dirt/unfiltered air out.
This is one of Synapse main selling points, the ability to cruise with the bov (diverter valve) open under vacuum conditions while still sealing tight once you get closer to atmosperic and then into boost. There is less restriction sucking through your BOV than through the whole system and finally your air filter.
Your non-Synapse BOV is supposed to be closed under cruise vacuum conditions, you change the springs to suit, they usually have directions as such so don't take it from me, contact your BOV manufacturer and they will tell you themselves. The main reason I chose Synapse is their unique approach, full flow within 100 ms instead of the largest freakin guillotine that anyone makes (however fast it decides to respond...).
Your non-Synapse BOV is supposed to be closed under cruise vacuum conditions, you change the springs to suit, they usually have directions as such so don't take it from me, contact your BOV manufacturer and they will tell you themselves. The main reason I chose Synapse is their unique approach, full flow within 100 ms instead of the largest freakin guillotine that anyone makes (however fast it decides to respond...).