Ebay RESPONS TMS GFB Dual Port BOV - "EFB"

JohnnyTightlips

JohnnyTightlips

Motorhead
Greenie N00B Member
Greenie Member
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I purchased and installed the ebay knock off GFB dual port from here http://www.ebay.com/itm/New-Mazdasp...ash=item4aefa1cf54:g:WvIAAOSwYHxWISBE&vxp=mtr I offered them 105$ and they took it.

I have been running this valve for 6 months with no issues at slightly higher than stock boost levels "VT OTS map".
I will include some pictures when I get more time. @SharksInSpace also owns this valve and got it for around 85$.

Quality - Looks good, adjuster is hard to turn but smooth. Trumpets are thinner metal but won't crush too easily. Valve looks like GFB looks to be machined well. Spring is heavy duty. Not sure if GFB whistle trumpet fits.

Install - Very straight forward install. I used their gasket as well with no issues. Remove the stock BOV and install this one. I had a longer vacumm line on hand and used that, can't recall if I for sure needed it.

Adjust - Once it was installed and set for about 50/50 vta I started to adjust it.
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I used that video as a reference.

Happiness - 10/10 sounds great and no issues at idle, even set for 100% vta I just get an occasional backfire but no idle issues.

Mine says xs power on it, @SharksInSpace got one without a decal and it was a little cheaper. It appears to be the same valve. He also took it apart to turn the vacumm port which I did not do and hopefully he can comment on this.

Sounds!!! - RICE RICE BABY! 35% VTA

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Pics -

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UPDATES!!!

The GFB Whistle Trumpet fits this valve. @SharksInSpace has included a video.
https://www.rallysportdirect.com/pa...-valve-whistling-trumpet-attachment-low-boost

Low boost attachment works well with this as you are not doing 100% vta.

gfb_5702_1
 
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My 'EFB' looks identical except for the XS Power decal missing from the top; it's just a blank lid (for now, I may decorate it myself) and I grabbed it for $80.99 shipped from China (still showed up in only 3 days - ordered on Tuesday and delivered on Friday). It was on discount when I bought it, looks like it's now back to the normal price of $89.99 but they might accept a lower number if you make an offer. The item descriptions between this and johnny's are literally a copy/paste job, so I fully believe they originated from the same manufacturer and are just coming through different distributors. http://www.ebay.com/itm/Dual-Port-D...996471?hash=item2cb6c61777:g:AjQAAOSwax5Yyql1

I installed the valve yesterday and am so far quite pleased with it; I have the bias at roughly 50/50 and it sounds great, and is giving me zero issues with rough idle or stumbling (there is a nice popping backfire when I shift, though, hah). Spring seemed pretty well adjusted out of the box but I did give it another turn or two just to make sure it wasn't opening too early. I'm on a 93 octane Freektune targeting 21.5psi and hit 22.3 this morning, so it's holding at higher than stock boost levels for sure (maybe I need to back the spring off slightly to avoid overboosting?). Going to wait until I have my CS turbo installed and tuned to see if it holds at the pressure levels that demands before I offload the CS BPV that this EFB has replaced, but I don't foresee any complications at this point in time.

My vacuum line is not long enough to be able to reach while the port was facing the same way as the bypass outlet, which is how it's oriented from factory and on johnny's setup, so I removed the top and rotated it 90* to work for my configuration. While I had it open, I popped the spring out to take a look at it: it is rather hefty, quite long and has a lot of tension behind it; took a lot more force than I'd anticipated to squeeze and hold everything back together in order to start the bolts back in. The piston inside also seems to be of high quality for the price, and right now I feel like this valve is quite a steal for anyone who is considering the GFB but balking at their $280 price tag. I would be curious to do a side-by-side comparison between the EFB and a true GFB in regards to quality of material and construction; my assumption is that the real GFB is a much more polished product in look and feel, but at the moment I'm not anticipating any issues running this valve.
 
How far can it be adjusted on the lighter side ? Can you set it to be easily opened by a finger when pushing the piston ?
 
Ummmmm, I have no idea but I doubt it, the spring is fairly hefty. I did 2 turns when I got it to add pressure to get my idle nice. Why would you want it so loose?
 
No i just want one that can open quick but maybe i should stick with BPV to avoid leak.
 
This thing opens plenty quick. You can open it by hand by pushing on the piston but it definitely takes some force (as it should). Any valve that can "easily" be opened by a finger push is probably guaranteed to leak...that spring tension is what keeps it closed at idle/low pressure.
 
Right this is why i will probably remain with a bpv. i may just try another brand and see if it can react better than my actual Forge bpv.
 
Jeff23spl said:
Right this is why i will probably remain with a bpv. i may just try another brand and see if it can react better than my actual Forge bpv.
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I had a forge, bought a "genuine" GFB.

(1) the forge has almost the exact same response, FWIW.

(2) from what I have seen, I would put the knockoff GFB up against the real thing in all but the most extreme situations.
 
Jeff23spl said:
Right this is why i will probably remain with a bpv. i may just try another brand and see if it can react better than my actual Forge bpv.
Click to expand...
I feel like I'm missing a piece of your logic...any bpv or bov still needs that spring pressure to keep from leaking at lower psi; the only difference is the ability to VTA vs full recirc.
 
SharksInSpace said:
I feel like I'm missing a piece of your logic...any bpv or bov still needs that spring pressure to keep from leaking at lower psi; the only difference is the ability to VTA vs full recirc.
Click to expand...

The BPV circulate only between turbo inlet and outlet (Both after the maf) so regardless if it is open or close at iddle the maf reading shouldn't be affected and the engine receive what it is read by the maf. But a VTA that leak would leak outside and add that air to the maf reading to drown the engine in fuel. Just try to run the oem valve into a VTA mode and you will get it. The spring help for the restriction between turbo discharge thru the IC back into the manifold. That differencial pressure would make the valve to open under boost if the spring isn't hard enough.

My problem is not a big deal. It started with the garrett, when i cruize around and i try to release the pedal very very slowly after a quick boost, the car shutter because the valve don't open or fluctuate a bit, i'm not sure. I have tried to increase spring rate and it get worse. But maybe if i diminish it even more, it may leak under boost and bypasse some usefull pressure back into the turbo inlet...
 
I'm aware of the difference between recirc and VTA, and it has nothing to do with spring pressure within the valve itself. If your spring is too light on tension, it is not going to hold target boost pressure, regardless of whether it is a BPV, BOV or hybrid.
 
If you have a guardian angel installed, stratified recommends going as soft as possible for preload since your GA is doing all of the work keeping the valve closed during idle and low load conditions. I haven't had much luck adjusting my real GFB's preload for VTA (idle will bounce around coming to a stop 8 - 16afr), but recirc mode seems to be working well.
 
SharksInSpace said:
I'm aware of the difference between recirc and VTA, and it has nothing to do with spring pressure within the valve itself. If your spring is too light on tension, it is not going to hold target boost pressure, regardless of whether it is a BPV, BOV or hybrid.
Click to expand...

I may be wrong but my understanding is that minimum spring pressure to keep it close under WOT would be just a little more than pressure lost into the IC. The top, where is the spring, is filled by intake pressure so both push against the turbo pressure to keep it closed, not just the spring.
 
Jeff23spl said:
I may be wrong but my understanding is that minimum spring pressure to keep it close under WOT would be just a little more than pressure lost into the IC. The top, where is the spring, is filled by intake pressure so both push against the turbo pressure to keep it closed, not just the spring.
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Yes and the way this valve is designed is that on light pressure release you are always recirc but when higher boost it will do a mix of recirc and vta. So idle is perfect.
 
This bit is where you lost me, and what makes me think you either have a misunderstanding in function of bpv/bov or what I mean by a leak:
Jeff23spl said:
The BPV circulate only between turbo inlet and outlet (Both after the maf) so regardless if it is open or close at iddle the maf reading shouldn't be affected and the engine receive what it is read by the maf.
Click to expand...
Even if you run a full recirc valve and outwardly lose no air from the system after the MAF has metered it, it's still a leak if the spring tension isn't high enough to hold the valve shut under boost and prevents you from hitting your target.

If you're targeting 25psi, for example, but at 22psi the boost pressure begins to overcome the valve's spring tension and open the valve, you now have a leak that is allowing air to either outwardly vent to atmosphere or bypass back into the intake tract instead of following through the cold pipe/TB/IM to enter the combustion chamber; regardless of VTA or recirc, this would stop boost pressure from building any further and prevent you from hitting your target of 25psi. That sequence is the same regardless of valve type; the only effect that recirc vs VTA has on our cars is in relation to AFR.


At the moment, I'm really just trying to figure out why you seem to be under the impression that a bpv is inherently better for avoiding a boost leak.
 
SharksInSpace said:
This bit is where you lost me, and what makes me think you either have a misunderstanding in function of bpv/bov or what I mean by a leak:

Even if you run a full recirc valve and outwardly lose no air from the system after the MAF has metered it, it's still a leak if the spring tension isn't high enough to hold the valve shut under boost and prevents you from hitting your target.

If you're targeting 25psi, for example, but at 22psi the boost pressure begins to overcome the valve's spring tension and open the valve, you now have a leak that is allowing air to either outwardly vent to atmosphere or bypass back into the intake tract instead of following through the cold pipe/TB/IM to enter the combustion chamber; regardless of VTA or recirc, this would stop boost pressure from building any further and prevent you from hitting your target of 25psi. That sequence is the same regardless of valve type; the only effect that recirc vs VTA has on our cars is in relation to AFR.
At the moment, I'm really just trying to figure out why you seem to be under the impression that a bpv is inherently better for avoiding a boost leak.
Click to expand...

Under boost, i agree that it is exactly the same for a BPV or BOV. But a thing is missing in your exemple. Under boost it is not the spring that keep the valve close but the spring+the boost pressure. So if your turbo discharge is at 22psi, you may have the intake at 20-21psi right ? So on the bottom of the valve, you have 22psi pushing against the piston to open it, but on the top of the valve, you have 20psi pushing back to keep it closed. So the real pressure remaining is about that 2psi that need to be beat by the spring. Then, if you take it to 30psi, you may have more lost into the ic so the lost may rise to 3 psi instead (real numbers depend of piping and specific IC) but it will remain a small number. All that to say that maybe a 8-10psi equivalent spring should be enough to keep it closed under 30psi of boost.
But under -10psi of vaccuum, a 8psi sping may not be enough to keep it closed...
 
Jeff23spl said:
Under boost, i agree that it is exactly the same for a BPV or BOV. But a thing is missing in your exemple. Under boost it is not the spring that keep the valve close but the spring+the boost pressure. So if your turbo discharge is at 22psi, you may have the intake at 20-21psi right ? So on the bottom of the valve, you have 22psi pushing against the piston to open it, but on the top of the valve, you have 20psi pushing back to keep it closed. So the real pressure remaining is about that 2psi that need to be beat by the spring. Then, if you take it to 30psi, you may have more lost into the ic so the lost may rise to 3 psi instead (real numbers depend of piping and specific IC) but it will remain a small number. All that to say that maybe a 8-10psi equivalent spring should be enough to keep it closed under 30psi of boost.
But under -10psi of vaccuum, a 8psi sping may not be enough to keep it closed...
Click to expand...
You are breaking my brain, just buy it or do not.
 
I still don't understand where your original implication that a BPV will be inherently better at avoiding a boost leak came from. Buy a hybrid and set the preload accordingly if you want cool noises, buy a standard BPV if you want to keep being French Canadian about it.
 
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