BOV help

[ek9_evo9]

Brother let me use his Greddy Type S BOV, he converted to single spring and when i slapped that baby on, it seems to bleed pressure without letting off the throttle.* IMO i think its because of the single spring setup, does anyone else have any ideas?

the sound is like a high pitched squeek during wot and boosting.

doesnt seem to happen on normal acceleration just on WOT.

thanks for any suggestions.

[earlyapex]

Brother let me use his Greddy Type S BOV, he converted to single spring and when i slapped that baby on, it seems to bleed pressure without letting off the throttle.* IMO i think its because of the single spring setup, does anyone else have any ideas?

the sound is like a high pitched squeek during wot and boosting.

doesnt seem to happen on normal acceleration just on WOT.

thanks for any suggestions.


It's not adjusted correctly, it's too loose so it's bleeding off boost.

[zyounker]

As earlyapex said, it is not setup correctly.. And you may have the wrong spring.

i run a single spring on mine and it works fine.. Mine originally came with 2 springs inside.. With 2 springs in, it would not blow off correctly and was causing compressor surge. SO i removed one spring and tightened it a little bit and it works great now.

[ek9_evo9]

Brother let me use his Greddy Type S BOV, he converted to single spring and when i slapped that baby on, it seems to bleed pressure without letting off the throttle. IMO i think its because of the single spring setup, does anyone else have any ideas?

the sound is like a high pitched squeek during wot and boosting.

doesnt seem to happen on normal acceleration just on WOT.

thanks for any suggestions.


It's not adjusted correctly, it's too loose so it's bleeding off boost.


i adjusted all the way to hard and still same thing



As earlyapex said, it is not setup correctly.. And you may have the wrong spring.

i run a single spring on mine and it works fine.. Mine originally came with 2 springs inside.. With 2 springs in, it would not blow off correctly and was causing compressor surge. SO i removed one spring and tightened it a little bit and it works great now.





you maybe right ill try switching springs and checking that out, although my 9 bov is fine for me i wanted to try the greddy one out.

how can you tell your getting compressor surge? is that a fluttering sound?

[zyounker]

Yeah, if i tightened mine too much it would flutter which i read as compressor surge. Not sure compressor surge is the right description, basically the blow off valve was not letting enough pressure out and would make the pressure wave bouce back and forth in the intake track between the throttle plate and compressor wheel.

Which can cause the nut on your compressor to back off and get eaten by your turbo. It also has been known to crack compressor wheel blades from stress.



Greddy also sells differnt springs, if yours doesnt have the one suited for your car. BTW My butt dyno says my car picked up a little power with the type-s.. I believe my stock BOV was leaking.. (04 GSR)

[ek9_evo9]

Yeah, if i tightened mine too much it would flutter which i read as compressor surge. Not sure compressor surge is the right description, basically the blow off valve was not letting enough pressure out and would make the pressure wave bouce back and forth in the intake track between the throttle plate and compressor wheel.

Which can cause the nut on your compressor to back off and get eaten by your turbo. It also has been known to crack compressor wheel blades from stress.



Greddy also sells differnt springs, if yours doesnt have the one suited for your car. BTW My butt dyno says my car picked up a little power with the type-s.. I believe my stock BOV was leaking.. (04 GSR)



wow i didnt know BOV made a difference in HP, but then again the buttdyno never lies hahahaha, i guess if it fixes a boost leak then i guess youd feel more of a difference

[evolvedevo9]

aren't u not even supposed to use VTA bovs with the evos?

[earlyapex]

aren't u not even supposed to use VTA bovs with the evos?


I don't think he said he was VTA?

[ek9_evo9]

aren't u not even supposed to use VTA bovs with the evos?


nah not vta, the greddy type s bov can vta with an adaptor im going to recirc.

[zyounker]

aren't u not even supposed to use VTA bovs with the evos?



Just to make sure (a lot of people install the type-s backwards), make sure that the side with the flange is going towards the tube going to the throttle body.. if the flange side connects to the turbo charge pipe betweeen the MAF, you have it backwards which will cause fluttering and not work right.


-Zach

nah not vta, the greddy type s bov can vta with an adaptor im going to recirc.

[ek9_evo9]

aren't u not even supposed to use VTA bovs with the evos?



Just to make sure (a lot of people install the type-s backwards), make sure that the side with the flange is going towards the tube going to the throttle body.. if the flange side connects to the turbo charge pipe betweeen the MAF, you have it backwards which will cause fluttering and not work right.


-Zach

nah not vta, the greddy type s bov can vta with an adaptor im going to recirc.



yah unfortunately i made that mistake before, i was thinking about using this bov now because i put in a blitz drop in filter and induction cover, seems to flutter a little after i let go of the gas when i go to WOT.

I was thinking maybe because the 9 stock BOV wasnt cutting it but im not sure, i didnt know going open air would make having an aftermarket bov necessary

[egui42]

The 9 bov works fine for what you have. I had my greddy on for a while, was just to loud. It's all about fine tuning the greddy.

[ek9_evo9]

The 9 bov works fine for what you have. I had my greddy on for a while, was just to loud. It's all about fine tuning the greddy.


you didnt get a small flutter sound after wot?

[earlyapex]

you didnt get a small flutter sound after wot?


That would be compressor surge.

[zyounker]

If it is fluttering when you let off (and its not installed backwards) then you have it too tight. The problem with the type-s is that when you tighten it up, the volume of air it can blowoff decreases.. IF you tighten it too much you get compressor surge as well.


Loosen it up until it stops fluttering at the top. if it makes a squaling sound you need to get a heavier spring.

(you can also use the lower nipple to actuate the type-s faster.)


-Zach

[reglaranang]

he doesn't have the type-s he has the rs i don't think my bro knew with model he had...

[ek9_evo9]

thats right it is a type rs, but i get a small flutter when i get off WOT using the stock BOV. which another reason why i want to use the greddy bov, funny thing is i did a search and no-one got a flutter just from running open air but i seem to have this problem.

[egui42]

Well, some tuners say that Evo's have little compressor surge stock. A little is okay, but a lot is bad for the turbo. Maybe you should take it to a shop to help you out or maybe someone on here can help you out in person.

[zyounker]

Yes, stock evos do not blow off correctly at low pressure.. You will notice this if you are on a hill give light throttle (enought to cross atmospheric pressure) and it will flutter when it lets off.

What i said earlier about loosening the top adjuster and changing the spring still applys to the type-rs.. If you tighten it too much it can not flow enough air so you get compressor surge.. If you use a little heavier spring and do not tighten the top adjuster too far it should blow off fine at wot.


Basically the top screw should be used for fine adjustment only.


NOTE: it is possible the type-RS is too small for the evo.. I have not used one myself. but it is almost identical to the type-s, so i would bet it should work fine.

[ek9_evo9]

thanks for all the help!

[ek9_evo9]

sorry for resurrecting this old thread, does anyone here use a drop in filter? the issue im having is with a blitz drop in, i hear compressor surge after releasing the gass, this is only when im shifting above 3k rpms. The surge is loud enough for me to hear so it got me worried the sound lasts for 1 second.

Kinda worried because i thought compressure surge is bad for your turbo.

i didnt expect this to happen on open airbox with a drop in. has this happened to anyone else? is there a fix for this? or is it even normal?

sorry if this is a newb ? this is my first turbo car.

[evo_dadi]

thats not a surge but more of air being recirculated back passing thru the dv or stock bov.surge is felt more like a bucking motion.

[zyounker]

sorry for resurrecting this old thread, does anyone here use a drop in filter? the issue im having is with a blitz drop in, i hear compressor surge after releasing the gass, this is only when im shifting above 3k rpms. The surge is loud enough for me to hear so it got me worried the sound lasts for 1 second.

Kinda worried because i thought compressure surge is bad for your turbo.

i didnt expect this to happen on open airbox with a drop in. has this happened to anyone else? is there a fix for this? or is it even normal?

sorry if this is a newb ? this is my first turbo car.


Yeah, thats probably not surge.. (It could be though) Does it have a fluter sound or just like a clean woosh sound? got to love tried to describe sounds over the internet :P Woosh=normal, flutter=incorrectly installed BOV.

If you changed your filter you are probably just hearing the Blow off from the Blow off valve.. but when you have a new airfilter you can actually here it better. This is normal.

[ek9_evo9]

thats not a surge but more of air being recirculated back passing thru the dv or stock bov.surge is felt more like a bucking motion.


thanks marcel! *i was getting kind of worried there



sorry for resurrecting this old thread, does anyone here use a drop in filter? the issue im having is with a blitz drop in, i hear compressor surge after releasing the gass, this is only when im shifting above 3k rpms. The surge is loud enough for me to hear so it got me worried the sound lasts for 1 second.

Kinda worried because i thought compressure surge is bad for your turbo.

i didnt expect this to happen on open airbox with a drop in. has this happened to anyone else? is there a fix for this? or is it even normal?

sorry if this is a newb ? this is my first turbo car.


Yeah, thats probably not surge.. (It could be though) Does it have a fluter sound or just like a clean woosh sound? got to love tried to describe sounds over the internet :P Woosh=normal, flutter=incorrectly installed BOV.

If you changed your filter you are probably just hearing the Blow off from the Blow off valve.. but when you have a new airfilter you can actually here it better. This is normal.



its a slight flutter.

I hear the woosh from the BOV/DV but before that is a slight flutter.

[zyounker]

If it is just a slight flutter, it can probably be ignored.. If your BOV has an adjuster, i would loosen it up a little and see if it goes away. Bascially, you want it as tight as possible without being too tight.

if it is too tight, the BOV can not bypass enough air and does not function correctly (at least with the greddy type-s style BOV.)


If this is the stock diverter valve. don't worry about it.

[ek9_evo9]

If it is just a slight flutter, it can probably be ignored.. If your BOV has an adjuster, i would loosen it up a little and see if it goes away. Bascially, you want it as tight as possible without being too tight.

if it is too tight, the BOV can not bypass enough air and does not function correctly (at least with the greddy type-s style BOV.)


If this is the stock diverter valve. don't worry about it.



i decided to put the stocker back on since originally i thought the greedy type s bov would fix that sound. :lol: