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Discussion Starter #1
Stock BOV
http://videos.streetfire.net/video/32fc00e...875016f536b.htm

Greddy knock Off BOV
http://videos.streetfire.net/video/56e7581...883012f2abc.htm


Picture and video clip. Bought the BOV off ebay for 30$ shipped, and add a APT adaptor for another 30$.
I removed the smaller spring inside the BOV, and left the big one in there. As you can see in the picture, I adjust it very tight with single spring. No fluttering or surge so far, It blow off for high RPM trottle change and shift.

Tried my best to reseal everything to pervent leak. The quality of the BOV is average, no major finish flaws, Ok paint finish and Ok polish job. I got the fake CF finishe, but I may paint the whole thing to black finish later.

Not sure how long will thing thing last, but I heard the only flaw in the knock off is the disphragm. I already bought a greddy disphragm, once the knock off one fails I will put the new one in.

I only have this for couple of days so I don't know how long will it last until the disphragm go out. It sounds quite loud even in recir mode (maybe twice as loud compare to stock). I only can hear the high pitch chirp in VTA mode, I guess the pipe somewhat blocked that sound. The biggest difference in sound between stock and the knock off is, for the stock BOV, all you can hear is the air sound, but the knock off also gives the mechanical clashing sound, and also the chirp sound if you run it in VTA. The sound level of my CAI, BOV and delete second cat is perfect for me, the combo sounds aggresive and sporty, but not loud and annoying.

It works great so far, I will update this if something goes wrong.
 

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Nice write-up.
 

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why did you take the small spring out?

also when i took apart the diaphram in the one i bought, i found it to be made of similar construction and quality of greddy's.
I also found the construction to be similar to that of greddy's
 

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Discussion Starter #4
why did you take the small spring out?

also when i took apart the diaphram in the one i bought, i found it to be made of similar construction and quality of greddy's.
I also found the construction to be similar to that of greddy's
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2 springs are too stiff for the car, they will make turbo surge.
 

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2 springs are too stiff for the car, they will make turbo surge.
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im running both springs. ive also done the single spring mod before. no surge here. you just need to tune it correctly.

btw, the real greddy makes a completely different sound.
 

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yup the real greddy makes a high pitched whistle sound as the valve is closing
 

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Can I do somthing to my stock blow off valve so I can hear it go off?

So far I cant hear my stock one go off at all?
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Or get an intake...
 

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Discussion Starter #10
yup the real greddy makes a high pitched whistle sound as the valve is closing
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It does make that high pitch whistle in VTA, just not as loud as the real deal.

My friend told me that this BOV sounds like gun shot...... I better not try to floor the car when police are around :guns:
 

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I've shot many guns before, but none of them have sounded anything like the whistle of a blow off valve. I wonder what kind of guns your friend has been shooting.
 

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I've shot many guns before, but none of them have sounded anything like the whistle of a blow off valve. I wonder what kind of guns your friend has been shooting.
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Potato guns.
 

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Recommended mod? Better off to spend the cash flow for the "real deal"?

Is the general consensus that you can run it with both springs, or does one really need to remove the smaller spring?
 

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Recommended mod? Better off to spend the cash flow for the "real deal"?

Is the general consensus that you can run it with both springs, or does one really need to remove the smaller spring?
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you can run 2 springs. the single spring mod isnt necessary.
 

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Discussion Starter #15
Recommended mod? Better off to spend the cash flow for the "real deal"?

Is the general consensus that you can run it with both springs, or does one really need to remove the smaller spring?
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I can't really say anything until I test it for couple of months. But so far it works great and feels great, and it only cost 60$. The reason why you need to remove the 2nd spring in the knock off is because the spring rate is different compare to the real deal. Knock off's spring rate is extra stiff.
 

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Discussion Starter #16
you can run 2 springs. the single spring mod isnt necessary.
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I put the smaller spring back into the BOV, and the BOV was able to recreate the greddy whistle sound at high RPM now. I set the spring pretty hard, but it still blow off at any throttle change. The BOV sounds complete different in low rpm and high rpm. When I use only 1 spring, the BOV sounds the same in all rpm range. The reason I only put 1 spring in the first place is because DSM board said that the knock off BOV spring is too stiff, unlike the real deal. I guess the knock off company changed the spring rate somehow.

Is the real deal the same? Only whistle at high rpm or all rpm range?
 

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Discussion Starter #18
Its a greddy type S replica. Pretty much all the components are exactly the same and exchangable (material is not identical). So people with broken type S bought the fake one for replacement parts. Its all all metal.
 

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the greddy whistles under everything, but it depends on how you tune it. mine is making the two tone sound that you can find on streetfire.net.
 

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Discussion Starter #20
the greddy whistles under everything, but it depends on how you tune it. mine is making the two tone sound that you can find on streetfire.net.
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Ya I was trying to play around different settings last hour. The sound does changes a lot depends on settings.
 
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