BOV dump
#19834
November 18, 2001 09:40 pm UTC
November 18, 2001 09:40 pm UTC
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Joined: Nov 2001
Posts: 3,720 Toronto
Darko Miodrag
OP
ok wait, maybe I am
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OP
ok wait, maybe I am
Joined: Nov 2001
Posts: 3,720
Toronto
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Yeah I know, this comes up every week and you all must be sick of it... but I'll ask anyway.
I was bored earlier today and decided to see how the stock BOV would sound if it dumped to the atmosphere. I disconnected the return hose and pinched and sealed it so no unmetered air can get past the MAS.
The thing sounds great, but of course the idle is pretty messed up. If I let off the gas and coast in neutral the revs drop to 400-500 and then climb back up. The engine doesn't stall, but it comes close. When the car is idling in the driveway, the revs stay between 700 and 1100, slowly climbing and falling.
My question is, what exaclty causes this? Does the BOV leak too much air, even at idle? Would some kind of 1way valve fix this somehow? I need ideas... I love the sound, but I'm not prepared to blow hundreds on a new BOV when the stock one is perfectly fine... and yes, I'm aware that the car runs rich when I let off the gas and accelerate again, but I don't think that makes too much difference. As for spooling, it's the same.
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Re: BOV dump
#19835
November 18, 2001 10:28 pm UTC
November 18, 2001 10:28 pm UTC
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Joined: Sep 1998
Posts: 6,079 Mississauga, Ontario
Jeff Mitchell
Senior Member, with Far TOO Much Time on Their Hands
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Senior Member, with Far TOO Much Time on Their Hands
Joined: Sep 1998
Posts: 6,079
Mississauga, Ontario
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Like you said, you're stalling because the BOV is leaking at idle. You can crush the BOV to make it stop leaking. It'll probably still stall when you're driving though. I'd recommend you just leave it the way it is. [ November 18, 2001: Message edited by: Jeff Mitchell ]
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Re: BOV dump
#19838
November 18, 2001 11:39 pm UTC
November 18, 2001 11:39 pm UTC
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Joined: Nov 2001
Posts: 3,720 Toronto
Darko Miodrag
OP
ok wait, maybe I am
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OP
ok wait, maybe I am
Joined: Nov 2001
Posts: 3,720
Toronto
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lol someone tried selling it for $50? Ouch. Hope nobody fell for it... I figured it would keep the valve from leaking any air up to 1psi... after that it would open and let the BOV function as it should. Since it's a 1way valve it would also keep the air out so it works both ways. I'll try it tomorrow and report back with my findings.
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Re: BOV dump
#19839
November 19, 2001 04:56 pm UTC
November 19, 2001 04:56 pm UTC
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Joined: Nov 2001
Posts: 3,720 Toronto
Darko Miodrag
OP
ok wait, maybe I am
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OP
ok wait, maybe I am
Joined: Nov 2001
Posts: 3,720
Toronto
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Well, it looks like the idea works... just not the way I made mine.
I went to CT and picked up a 1" gated 1way check valve from the plumbing department, and a barbed fitting to go with it. I cut about 2 inches of hose from the BOV return line and attached one end to the BOV outlet and the other to the barbed fitting which is attached to the check valve.
The valve is not supposed to let any air back in, but the problem is that it doesn't swing shut fast enough, and it doesn't stay sealed.
What I tried after I realized it doesn't work is to put my finger in the valve (its a big whole, and you can snap the gate shut with your hand) and rev the engine manually... I revved up, let go, and the gate swung open releasing air, then when all the pressure was almost gone I snapped the gate shut with my finger. The idle dropped normally to about 800 (I could hear it) and it didn't fluctuate one bit.
Basically now I gotta go back to CT and buy a good spring loaded valve that will snap shut at the right time and keep a good seal.
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Re: BOV dump
#19840
November 19, 2001 05:38 pm UTC
November 19, 2001 05:38 pm UTC
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Joined: Jul 1999
Posts: 650 Unionville, Ontario, Canada
Edwin Lau
Member
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Member
Joined: Jul 1999
Posts: 650
Unionville, Ontario, Canada
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Just get an aftermarket BOV, it gives the nice whoosh followed by a bang (<-just my car). The bang comes from running rich and then backfiring...hahaha
laux3640@mach1.wlu.ca 92 Talon TSI AWD less 89 Probe GT
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Re: BOV dump
#19843
November 19, 2001 10:10 pm UTC
November 19, 2001 10:10 pm UTC
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Joined: Apr 2001
Posts: 1,212 Chatham,Ontario canada
Jeremy Gore
Serious Member
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Serious Member
Joined: Apr 2001
Posts: 1,212
Chatham,Ontario canada
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I have the answer for all yous guys that love the WOSHHHHHHH...and that is get a new blow off valve i put the turbo XS racing BOV valve on and I love it it does not idle bad att all it is one of the only BOV'S that close on idle to keep the idle right and you can get this at JRP in toronto costs about 300 bucks but way worth it to see the peoples faces when I go by them and let of the gas to get the big bang..... keep on boosting.
Jer.....
Corporal Jeremy J Gore D.N.D.
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Re: BOV dump
#19845
November 20, 2001 12:46 am UTC
November 20, 2001 12:46 am UTC
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Joined: Nov 2001
Posts: 3,720 Toronto
Darko Miodrag
OP
ok wait, maybe I am
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OP
ok wait, maybe I am
Joined: Nov 2001
Posts: 3,720
Toronto
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Gates, it works wonderfully.
I just got back from Home Depot an hour ago. I picked up a "2 stage check valve".
Basically it's a long tube (maybe 5 inches) with 2 plastic inserts. Each plastic cylinder has a spring operated piston that opens at a certain psi. I took out the second stage piston and left the insert in there. The first spring was too tight so I cut in 2 thirds away and replaced the parts. I used a small part of the dump tube to connect to the blow off valve, and the other side connected to the valve by a barbed 1" fitting.
I played with the spring for an hour, slowly cutting away at it and testing the sound. Right now my idle is ROCK STEADY at 800rpm. It dips below if I rev up really high and let off, but that's because the spring is too short. The sound of the stock BOV is great and pretty damn loud. I had my buddy stand out on the street and he heard my 1-2 shift from about 500 feet away. With the check valve on, he told me I lost about 25% of the sound but it's still nice. Im gonna continue tweaking it to get the most sound out of it, but I'm very happy that it works as it should.
The only downside is that the 2 stage valve costs $39.99... I'm a crook and I put the valve in a box which had a normal gated valve in it originally and got it for $10. What can I say... I was desparate.
If you can find a regular spring loaded valve it should run ya $20 tops.
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Re: BOV dump
#19846
November 20, 2001 03:25 am UTC
November 20, 2001 03:25 am UTC
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Joined: Aug 1998
Posts: 2,071 Windsor/Toronto Ont
Peter Tarach
Insane Member
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Insane Member
Joined: Aug 1998
Posts: 2,071
Windsor/Toronto Ont
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This is an email I received from another DSM guy who did almost exactly what Darko did.
I have yet to try this though.
Sent: Friday, November 02, 2001 6:33 PM Subject: bov check valve
Hi, I designed this valve to use on my car which is a 1992 AWD Talon. I don't see any reason that it shouldn't work equally nice on a second generation car, as the basic design of the bov is the same although the 2nd gen leaks at high boost. This valve will not prevent any bov from leaking pressure at high boost, what it will do is allow you to vent your bov to atmosphere without suffering idle problems. It is a one way valve(exit only) so it makes it impossible to introduce unmetered air into the intake tract. The reason this works, is because the bov is wide open at idle, or any time there is negative manifold pressure. (vacuum) any time there is vacuum in the manifold, the check valve will be completely sealed. So in conclusion, you get to experience the sound of a vented bov, and retain the streetability of a stock setup. If youve never heard a vented bov, you will be very pleased with this. it sounds like a semi releasing its air brakes every time you shift. Here it is: This thing is made of 3 basic pieces. 1. Check valve 2. male adapter 3. rubber coupler Screw the male adapter (nipple fitting) into the end of the check valve with the nut and spring.(inlet end) There is an arrow stamped on the check valve showing direction of flow. Use a piece of rubber hose about 3" long that is the same diameter as the stock bov dump tube to attach the assembly to the stock bov outlet. Plug the dump tube opening on the turbo inlet hose using a 35mm film canister, or something similar. I drilled some large holes around the perimeter of the check valve outlet to diffuse the exiting air. (more flow and noise.) I bought the parts at Menards. They are made by a company called Water Source. (they are well pump parts). The check valve is part number cv100, and cost $9.88. The male adapter is ma100 or mar100, and cost $6.49. Pretty cheap, Huh? If your local building company doesn't stock them, I got their address and phone number for your convenience. Water Source P.O.Box 7615 Des Moines IA, 50322 1-800-346-7611 : If you have anymore questions, don't hesitate to ask. For those of you who suggested that I charge for this, I'm content providing this for free as it didn't cost me anything to think it up. I just hope that all of you will do the same if you come up with something cheap and fast! Corey
95 Nissan 240 SX - SR Powered - 324whp@16psi 95 Honda Accord - H22A 191whp, 152tq. Melted Piston
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Re: BOV dump
#19849
November 20, 2001 05:18 am UTC
November 20, 2001 05:18 am UTC
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Joined: Nov 2001
Posts: 3,720 Toronto
Darko Miodrag
OP
ok wait, maybe I am
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OP
ok wait, maybe I am
Joined: Nov 2001
Posts: 3,720
Toronto
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Originally posted by Jeremy Clarke: I have a question though, does the $300 BOV do anything better than my stock one except make the noise and hold more pressure (more pressure than I will ever need)
If I just wanted the sound why would I pay $300 That's my mentality... the stock 1G BOV is excellent, and it can hold plenty of pressure and even more if it's crushed. I'm very happy with this little contraption... sure a new BOV would dress up the engine bay and make a louder sound but for $300 I could get a downpipe and a uic pipe and get some REAL gains.
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Re: BOV dump
#19851
November 20, 2001 02:51 pm UTC
November 20, 2001 02:51 pm UTC
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Joined: Sep 1998
Posts: 6,079 Mississauga, Ontario
Jeff Mitchell
Senior Member, with Far TOO Much Time on Their Hands
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Senior Member, with Far TOO Much Time on Their Hands
Joined: Sep 1998
Posts: 6,079
Mississauga, Ontario
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Originally posted by Jeremy Clarke: I have a question though, does the $300 BOV do anything better than my stock one except make the noise and hold more pressure (more pressure than I will ever need) An aftermarket BOV can hold more boost, can flow more air, close more quickly after blowing off, don't leak at idle, and they are fully adjustable. Most of these things don't really matter much until you're fairly up there in terms of modifications. Originally posted by Jeremy Clarke: If I just wanted the sound why would I pay $300 The 1G BOV is very good for a stock piece, but for alot of us (i.e. 2G owners) it's *not* the stock piece. So if we're going to change it, why not get something even better? I'm sure alot of the people you hear talking about aftermarket BOVs are 2G owners. I personally wouldn't change it if I had the 1G BOV stock, but I didn't, so I found a cheap used HKS unit. Oh, and keep in mind that the aftermarket ones are usually much louder. I'd be interested in hearing one with the check valve though, to see how loud it is. Jeff Mitchell
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Re: BOV dump
#19852
November 20, 2001 03:04 pm UTC
November 20, 2001 03:04 pm UTC
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Joined: Nov 2001
Posts: 1,914 Toronto, Ontario
Jakub Kowalczyk
Serious Member
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Serious Member
Joined: Nov 2001
Posts: 1,914
Toronto, Ontario
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Hey Darko, where do you live? Would you help me do thae same mod?
GOT SURGE?
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Re: BOV dump
#19857
November 20, 2001 06:27 pm UTC
November 20, 2001 06:27 pm UTC
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Joined: Jul 2001
Posts: 378 Toronto, ON
Victor Belokour
Member
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Member
Joined: Jul 2001
Posts: 378
Toronto, ON
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Darko, you think you can do some sort of a final write up with pics? A VFAQ?
92 Suzuki Swift (!)
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Re: BOV dump
#19861
November 20, 2001 07:12 pm UTC
November 20, 2001 07:12 pm UTC
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Joined: Jan 2001
Posts: 121 London
Brian Micks
Member
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Member
Joined: Jan 2001
Posts: 121
London
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That sounds like a great winter project. When I took the dump tube off my BOV the idle was not to bad but I put it back on so the idle was perfect. I would not spent $300 for a new BOV and all you get is sound. Also Jerry, where did you get the body kit? or is it another car's modded to fit yours?
Brian Micks 1990 Eagle Talon TSI AWD Getting more and more mods everyday!!
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Re: BOV dump
#19862
November 20, 2001 07:14 pm UTC
November 20, 2001 07:14 pm UTC
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Joined: Jan 2001
Posts: 121 London
Brian Micks
Member
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Member
Joined: Jan 2001
Posts: 121
London
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sorry Jeremy, what was i thinking?
Brian Micks 1990 Eagle Talon TSI AWD Getting more and more mods everyday!!
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Re: BOV dump
#19866
November 23, 2001 05:39 pm UTC
November 23, 2001 05:39 pm UTC
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Joined: Apr 2001
Posts: 385 Heart Lake/Brampton, On
JR Sahadat
Member
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Member
Joined: Apr 2001
Posts: 385
Heart Lake/Brampton, On
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That simulated sound sounds like a the cracking of a bottle of pop....I see a lawsuit coming on from Coke/Pepsi.
1995 Red "Eclipse looking Talon" President/CEO GarageStar Racing MSN:the_juicer_76@hotmail.com
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Re: BOV dump
#19870
November 25, 2001 10:00 pm UTC
November 25, 2001 10:00 pm UTC
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Joined: May 2001
Posts: 1,575 Mississauga, ON
Rafal Kraskiewicz
Serious Member
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Serious Member
Joined: May 2001
Posts: 1,575
Mississauga, ON
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and the manufacturer is B&K.
I'm going to look through our inventory at work, we carry all sorts of valves, fittings, maybe I can borrow something from them.
'97 Cherokee '92 Talon TSi AWD
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