# BOV/recirculating valve question???????? **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [May 26, 2006, 7:46am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560 "2006-05-26T07:46:37Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 7:46am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/1 "2006-05-26T07:46:37Z")
I have a Forge Motorsport recirculating valve on my Evolution and when I am in fifth gear the valve “flutters” like it can’t hold boost BUT, it holds boost fine when I take off at full boost and go through the lower gears. In fact it will hold much higher boost in lower gears. I am thinking it might have something to do with vacuum or the fact the fifth gear is so huge. Fourth only goes to about 100mh and fifth goes to like 160mph or 170mph. Any suggestions would be appreciated. Thanks. Mike ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 7:50am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/2 "2006-05-26T07:50:14Z")
One other possibility I thought of was the air pressure under the hood at higher speeds.:gotme: (Just trying to guess) ---
**Author:** ![focusinprogress](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/focusinprogress/32/7227_2.png) [@focusinprogress](https://forums.speedlife.net/u/focusinprogress)\ **Post date:** [May 26, 2006, 8:20am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/3 "2006-05-26T08:20:45Z")
is it still setup as recirc or vented to atmosphere? ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 8:44am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/4 "2006-05-26T08:44:37Z")
It is set up for recirc. still. ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [May 26, 2006, 8:47am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/5 "2006-05-26T08:47:06Z")
> [@AWDrifter](#): > > I have a Forge Motorsport recirculating valve on my Evolution and when I am in fifth gear the valve “flutters” like it can’t hold boost BUT, it holds boost fine when I take off at full boost and go through the lower gears. > In fact it will hold much higher boost in lower gears. > I am thinking it might have something to do with vacuum or the fact the fifth gear is so huge. Fourth only goes to about 100mh and fifth goes to like 160mph or 170mph. > Any suggestions would be appreciated. > Thanks. > Mike wow, 5th is huge. could be the duration that you stay in that gear? ---
**Author:** ![Tkklemann](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tkklemann/32/7298_2.png) [@Tkklemann](https://forums.speedlife.net/u/Tkklemann)\ **Post date:** [May 26, 2006, 8:49am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/6 "2006-05-26T08:49:28Z")
Most people don’t have any problems with the Forge unit. Besides, what the hell are you going that fast for? Hahaha!! How tight do you have the pre-load? It’s adjustable right? You might be able to hook a brake bleeder vacuum (Like Mightyvac) up to it and see what inHg it is opening up at. You might be suprised to find that it is opening up in lower gears, but you just can’t hear it/or tell. ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 8:56am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/7 "2006-05-26T08:56:05Z")
> [@newman](#): > > wow, 5th is huge. could be the duration that you stay in that gear? Yeah, fifth kills 1/4 miles times. I am thinking that because fifth is so long the turbo can build boost at lower rpm and that is somehow affecting the valve operation. Again I am just guessing with my amount of knowledge. ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 8:57am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/8 "2006-05-26T08:57:27Z")
> [@Tkklemann](#): > > Most people don’t have any problems with the Forge unit. > > Besides, what the hell are you going that fast for? Hahaha!! > > How tight do you have the pre-load? It’s adjustable right? > > You might be able to hook a brake bleeder vacuum (Like Mightyvac) up to it > and see what inHg it is opening up at. You might be suprised to find that it is > opening up in lower gears, but you just can’t hear it/or tell. Good point, I cannot hear or feel it but it might still be happening. I can’t hear a thing at WOT.:biglaugh: ---
**Author:** ![Tkklemann](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tkklemann/32/7298_2.png) [@Tkklemann](https://forums.speedlife.net/u/Tkklemann)\ **Post date:** [May 26, 2006, 9:03am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/9 "2006-05-26T09:03:50Z")
That’s exactly what I was thinking, at WOT you really can’t hear much… > [@AWDrifter](#): > > Good point, I cannot hear or feel it but it might still be happening. > I can’t hear a thing at WOT.:biglaugh: ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 9:51am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/10 "2006-05-26T09:51:39Z")
I just remembered (duh) my boost gage does not flutter in other gears.:smash2: So I would think it is working properly in those gears. ---
**Author:** ![focusinprogress](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/focusinprogress/32/7227_2.png) [@focusinprogress](https://forums.speedlife.net/u/focusinprogress)\ **Post date:** [May 26, 2006, 9:59am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/11 "2006-05-26T09:59:27Z")
so your gauge flutters in fifth? ---
**Author:** ![TRP951](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TRP951](https://forums.speedlife.net/u/TRP951)\ **Post date:** [May 26, 2006, 10:00am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/12 "2006-05-26T10:00:07Z")
Which forge valve do you have the piston or the diaphram? how do you have it set up and what spring are you using? ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 10:36am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/13 "2006-05-26T10:36:30Z")
Yeah, it flutters in fifth. It is the piston type and I am using the stiffest spring it came with because I am running pretty high boost. Maybe I need a stronger spring. ---
**Author:** ![TRP951](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TRP951](https://forums.speedlife.net/u/TRP951)\ **Post date:** [May 26, 2006, 10:45am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/14 "2006-05-26T10:45:49Z")
I am running the softest spring with the piston one, any other stiffer spring and it would flutter for me also. I set it up so pressure from the turbo was on the side port and it went out the bottom when it opened up. If i recall i was told to set it up that way so that the spring pressure was ~vacuum at idle and since when you go on boost there is no vacuum the boost should hold it shut ---
**Author:** ![TRP951](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TRP951](https://forums.speedlife.net/u/TRP951)\ **Post date:** [May 26, 2006, 10:48am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/15 "2006-05-26T10:48:09Z")
Also this held when i accidentally spiked to 21psi when trying to figure out my greddy profec settings ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 10:58am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/16 "2006-05-26T10:58:45Z")
> [@TRP951](#): > > I am running the softest spring with the piston one, any other stiffer spring and it would flutter for me also. I set it up so pressure from the turbo was on the side port and it went out the bottom when it opened up. If i recall i was told to set it up that way so that the spring pressure was ~vacuum at idle and since when you go on boost there is no vacuum the boost should hold it shut Maybe I will try that even though it doesn’t make sense to me. It seems like you would get massive turbo surge that way.:gotme: ---
**Author:** ![TRP951](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TRP951](https://forums.speedlife.net/u/TRP951)\ **Post date:** [May 26, 2006, 11:06am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/17 "2006-05-26T11:06:17Z")
I was told by forge they discourage installing the piston valves in reverse orientation. they said hook the side port to the intercooler pipe and and bottom to the MAF pipe. ---
**Author:** ![Daddie](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/daddie/32/7621_2.png) [@Daddie](https://forums.speedlife.net/u/Daddie)\ **Post date:** [May 26, 2006, 11:15am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/18 "2006-05-26T11:15:50Z")
Turbo surge? just blow your current turbo and by a FP Red already 😛 ---
**Author:** ![Blue\_Eyed\_Devil](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_eyed_devil/32/7292_2.png) [@Blue\_Eyed\_Devil](https://forums.speedlife.net/u/Blue_Eyed_Devil)\ **Post date:** [May 26, 2006, 11:19am UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/19 "2006-05-26T11:19:26Z")
> [@Daddie](#): > > Turbo surge? just blow your current turbo and by a FP Red already 😛 Shhhhhh!:snky: :biglaugh: (I wish) ---
**Author:** ![TRP951](https://avatars.discourse-cdn.com/v4/letter/t/b77776/32.png) [@TRP951](https://forums.speedlife.net/u/TRP951)\ **Post date:** [May 27, 2006, 1:32pm UTC](https://forums.speedlife.net/t/bov-recirculating-valve-question/12560/20 "2006-05-27T13:32:50Z")
any luck trying that?