What's the deal with blow off valves?
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Rep Power: 263 What's the deal with blow off valves?
I really like the way that the Greddy Type S sounds. I donno, I just like it. I also think that the Tial BOV is cool, but not as cool sounding.
I read some comments on a video of a greddy type S BOV, that said, oh yeah something something Tial is the best on the market... if you're serious about performance, get a Tial, or if you're a dumb ricer get a greddy.
I know that the sound of the BOV shouldn't really be a factor in choosing components... because you should be choosing the one that's the best quality...or whatever.
What does everyone think about this?
And one last question, are there any boosted 7th gens here that use something other then the Tial BOV? Post pics! Or video/sound clips!
I'm just curious...I know I won't be able to afford a turbo kit for like 100 years, but whatev.
I read some comments on a video of a greddy type S BOV, that said, oh yeah something something Tial is the best on the market... if you're serious about performance, get a Tial, or if you're a dumb ricer get a greddy.
I know that the sound of the BOV shouldn't really be a factor in choosing components... because you should be choosing the one that's the best quality...or whatever.
What does everyone think about this?
And one last question, are there any boosted 7th gens here that use something other then the Tial BOV? Post pics! Or video/sound clips!
I'm just curious...I know I won't be able to afford a turbo kit for like 100 years, but whatev.
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Rep Power: 263 Re: What's the deal with blow off valves?
I just found a cool video of the difference between the Type S, RS, and the HKS SSQV.
http://www.youtube.com/watch?v=FszbPFnxZKE
http://www.youtube.com/watch?v=FszbPFnxZKE
#3
Re: What's the deal with blow off valves?
A blow off valve is a blow off valve.....it dumps excess pressure....directly to the atmosphere or back into the system.......Tial, HKS, Greddy....they're all top notch companies.....I bet they're good blow off valves.....Everyone I know runs a tial....even 500whp + cars.....no one every has any issues.....Thats why I chose a tial..plus....my dezoid pipe already had the tial flange on it
I do have a buddy that runs a greddy on his turbo si....sounds better than my tial and it works just the same....no issues.
I do have a buddy that runs a greddy on his turbo si....sounds better than my tial and it works just the same....no issues.
Last edited by FoSho; 06-26-2008 at 11:22 AM.
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Rep Power: 219 Re: What's the deal with blow off valves?
at the same time so many people run HKS too .. i run tial cuz it came with my kit and i love it + great quality .. if i were to ever change i'd go with the hks ssqv .. my tuners 780whp supra runs that
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Rep Power: 263 Re: What's the deal with blow off valves?
That's good to hear. Most of the time people on the internet just talk smack about something because they have a personal issue with it, rather then a serious performance problem.
When I was browsing videos I found a video of a R34 with the greddy type S on it, and I was thinking to myself, if it's such a bad/ricer BOV, then why would this guy get one... I don't know, heh. I just like the Idea of personalizing a turbo system, known what I mean.
Is anyone here running something besides the Tial?
When I was browsing videos I found a video of a R34 with the greddy type S on it, and I was thinking to myself, if it's such a bad/ricer BOV, then why would this guy get one... I don't know, heh. I just like the Idea of personalizing a turbo system, known what I mean.
Is anyone here running something besides the Tial?
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Rep Power: 399 Re: What's the deal with blow off valves?
to my knowledge, greddy discontinued the S valve a long time ago... they make the RS now.
I've got one, it sounds good above 9 or 10 psi, below that, it just dumps air. Havent had an issue with it leaking or sticking, just have to get the thing dialed in right, which can take a little while.
I've got one, it sounds good above 9 or 10 psi, below that, it just dumps air. Havent had an issue with it leaking or sticking, just have to get the thing dialed in right, which can take a little while.
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Here's a BOV question. I noticed the new Tials come with different springs for different PSI. This does not make sense to me. I understand that you use different spring rates with a WG, but not a BOV. Anyone know why a BOV would have a different spring rate?
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Rep Power: 263 Re: What's the deal with blow off valves?
That is a good question, bumping, because I'm curious of the answer too.
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Rep Power: 213 Re: What's the deal with blow off valves?
Blow off valve/Dump valve
When a turbo is "working" (you have the foot on the accelerator & its producing "boost") the turbo is compressing the air to get more into the cylinders thus the more air in with fuel gives you more power. This air is passed through the Intercooler to cool it off (because when you compress the air it gets hot, but the engine needs air thats as cool as possible to get that power). Then it goes through the (TB) throttle body & into the intake manifold/engine. When the turbo is compressing this air, you can imagine there is a lot of air under pressure passing through the throttle butterfly which is open when you are pressing the accelerator. If you lift off the throttle to change a gear or slow down the throttle butterfly closes. Then this is where the air goes and there is a lot of it under pressure. Normally it gets trapped and produces backpressure (ex: it pushes back against the turbine wheel) which can damage the turbo over time. It forces the turbo to slow down and/or stop completely very suddenly. So, when you step on the accelerator again, it takes awhile for the turbo to spin back up to operating speed (Turbo lag). A (BOV Aka:dump valve, vents this excess pressure created when you lift off the throttle. It has a unique sound to it aswell and also keeping the turbo spinning at all times & prolonging its lifespan.
When a turbo is "working" (you have the foot on the accelerator & its producing "boost") the turbo is compressing the air to get more into the cylinders thus the more air in with fuel gives you more power. This air is passed through the Intercooler to cool it off (because when you compress the air it gets hot, but the engine needs air thats as cool as possible to get that power). Then it goes through the (TB) throttle body & into the intake manifold/engine. When the turbo is compressing this air, you can imagine there is a lot of air under pressure passing through the throttle butterfly which is open when you are pressing the accelerator. If you lift off the throttle to change a gear or slow down the throttle butterfly closes. Then this is where the air goes and there is a lot of it under pressure. Normally it gets trapped and produces backpressure (ex: it pushes back against the turbine wheel) which can damage the turbo over time. It forces the turbo to slow down and/or stop completely very suddenly. So, when you step on the accelerator again, it takes awhile for the turbo to spin back up to operating speed (Turbo lag). A (BOV Aka:dump valve, vents this excess pressure created when you lift off the throttle. It has a unique sound to it aswell and also keeping the turbo spinning at all times & prolonging its lifespan.
Last edited by FGCOUPE; 07-07-2008 at 12:02 AM.
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Rep Power: 272 Re: What's the deal with blow off valves?
Same thing goes for the blitz bov. If you are boosting under 18psi u use the stock spring included. If anything ober 18 then u need to get the upgraded spring seen here
http://www.blitz-performance.com/ind...index&cPath=53
Other BOV use the adjustment screw on top as there means of adjusting how much psi it can hold which gives it a range of psi it can hold. Some companies carry different types of BOV like how Greddy does with there BOV's which can be seen here
http://www.greddy.com/products/displ...SubCategory=18
regardless if it was adjusting spring rate by the screw on top of the bov or changing springs. it was always there for many many years but u just never noticed it!!!.. haha... Mainly the reason u never noticed it was it on top of the greddy it would say "soft" or "hard" on it. Most instructions say to adjust the screww till there is no air leak from the bov under idle and some say otherwise. Essentially u turning the screw adjusts how stiff the spring is on the inside
Last edited by xproductionz; 06-29-2008 at 02:07 PM.
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Hmmm, I think that's close, but after reading the specs again I notice they rate the springs in Hgs of vacuum vice PSI of boost. The logic is on the tip of my brain, but I'm all doped up on Benadryl (UK lawn mowing + summer = suck for 'foos) and can't think straight cuz I'm so tired.
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Rep Power: 272 Re: What's the deal with blow off valves?
Hmmm, I think that's close, but after reading the specs again I notice they rate the springs in Hgs of vacuum vice PSI of boost. The logic is on the tip of my brain, but I'm all doped up on Benadryl (UK lawn mowing + summer = suck for 'foos) and can't think straight cuz I'm so tired.
also the design of the many types of BOV will have different setup techniques. theres push-type and pull-type bovs. Typical push-type blow off valves require spring load settings for each vehicle specification. If the spring load setting is too low, the valve may leak under high boost and the desired boost setting may not be reach. If the spring load setting is too strong, it may not open at low boost. Thats why u have either adjusmtne screws and different springs
Greddy tells you to start the car and check the BOV at idle and adjust the screw till there is no air coming out of the BOV at IDLE. Which means its in VAC or HG. Tial just gets rid of this adjustment screw all together and just uses variable springs instead.
On the other hand i have a HKS ssq bov which uses a pull-type system which doesnt use a spring and an adjustment screw
i remember how some of the older wastegates used the same concept as well. There used to be one (forogot which one) where if the adjustment screw was all the way up the wastgate would hold 9psi and screw it all the way down it would hold 12psi.
Last edited by xproductionz; 06-29-2008 at 02:30 PM.
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Yeah, the deltagate uses a spring adjustment.
Ahah!!!
Now I understand the reason they use vacuum ratings for the springs vice pressure ratings. It's for what level of vacuum that the BOV closes, allowing boost pressure to build. I think anyway.
I mean if they were basing it off the way you explained (which makes sense) then Tial would list the springs by PSI instead of Hg. Here's what I'm talking about from Tial's FAQ on their new Q-model BOV. I think they're talking for the level of vacuum your motor produces at idle determines which spring you use.
Engine Vacuum Reading............Color............Use Spring
- 22 and -23 in/Hg............ ............-12 Psi (-24 in/Hg )
- 20 and -21 in/Hg............Pink............-11 Psi (-22 in/Hg )
- 16 and -19 in/Hg............Un-painted............-10 Psi (-20 in/Hg )
- 12 and -15 in/Hg.............White............-8 Psi (-16 in/Hg )
- 8 and -11 in/Hg...............Black............-6 Psi (-12 in/Hg )
Ahah!!!
Now I understand the reason they use vacuum ratings for the springs vice pressure ratings. It's for what level of vacuum that the BOV closes, allowing boost pressure to build. I think anyway.
I mean if they were basing it off the way you explained (which makes sense) then Tial would list the springs by PSI instead of Hg. Here's what I'm talking about from Tial's FAQ on their new Q-model BOV. I think they're talking for the level of vacuum your motor produces at idle determines which spring you use.
Engine Vacuum Reading............Color............Use Spring
- 22 and -23 in/Hg............ ............-12 Psi (-24 in/Hg )
- 20 and -21 in/Hg............Pink............-11 Psi (-22 in/Hg )
- 16 and -19 in/Hg............Un-painted............-10 Psi (-20 in/Hg )
- 12 and -15 in/Hg.............White............-8 Psi (-16 in/Hg )
- 8 and -11 in/Hg...............Black............-6 Psi (-12 in/Hg )
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Ahh. I just re-read our posts. We're saying the same thing with different words. I'm going to go lie down with washcloth on my head before my brain overheats.
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Rep Power: 263 Re: What's the deal with blow off valves?
^That's fuggin dumb. I saw that when I was searching, but didn't watch it. If you really want to see something funny, search for the video with the duck call thing on the BOV, that's actually funny.
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Rep Power: 303 Re: What's the deal with blow off valves?
to my knowledge, greddy discontinued the S valve a long time ago... they make the RS now.
I've got one, it sounds good above 9 or 10 psi, below that, it just dumps air. Havent had an issue with it leaking or sticking, just have to get the thing dialed in right, which can take a little while.
I've got one, it sounds good above 9 or 10 psi, below that, it just dumps air. Havent had an issue with it leaking or sticking, just have to get the thing dialed in right, which can take a little while.
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Rep Power: 263 Re: What's the deal with blow off valves?
know what's sad, I like the sound of the type S so much that I want to buy it before it gets too hard to find, even though I'm not turbo.... that's pretty sad... heh, I'm seriously going to do it though. maybe
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ive never actually heard of anyone using a BOV on a non-turbo car? wow!
that would mess someone up with a N/A car though....just blurp the throttle a few times at a light and hear it go off. If the person next to you was even thinking on givin it a shot might think twice?
heheh
that would mess someone up with a N/A car though....just blurp the throttle a few times at a light and hear it go off. If the person next to you was even thinking on givin it a shot might think twice?
heheh
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Rep Power: 263 Re: What's the deal with blow off valves?
ive never actually heard of anyone using a BOV on a non-turbo car? wow!
that would mess someone up with a N/A car though....just blurp the throttle a few times at a light and hear it go off. If the person next to you was even thinking on givin it a shot might think twice?
heheh
that would mess someone up with a N/A car though....just blurp the throttle a few times at a light and hear it go off. If the person next to you was even thinking on givin it a shot might think twice?
heheh
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Rep Power: 263 Re: What's the deal with blow off valves?
ive never actually heard of anyone using a BOV on a non-turbo car? wow!
that would mess someone up with a N/A car though....just blurp the throttle a few times at a light and hear it go off. If the person next to you was even thinking on givin it a shot might think twice?
heheh
that would mess someone up with a N/A car though....just blurp the throttle a few times at a light and hear it go off. If the person next to you was even thinking on givin it a shot might think twice?
heheh
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Rep Power: 255 Re: What's the deal with blow off valves?
I have the GReddy Type S. My adjustment screw broke, so basically I get massive compressor surge (instead of one constant sound its psh-sh-sh-sh-sh-sh)... but as everyone may remember, I'm broke so it's gonna stay like that no matter how much it hurts the car.
I'm 20,000 miles strong since my rebuild last year... and my bad tune... and no wideband. Honda really builds solid motors and Wiseco/Crower build really reliable internals.
I'm 20,000 miles strong since my rebuild last year... and my bad tune... and no wideband. Honda really builds solid motors and Wiseco/Crower build really reliable internals.
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Rep Power: 325 Re: What's the deal with blow off valves?
Yeah, because when the throttle plate closes, air is still going into the engine..
It doesn't cause a backup and surge the turbo compressor instead or anything...DUH. You know, for a guy who thinks he knows so much, you don't know ****.
It doesn't cause a backup and surge the turbo compressor instead or anything...DUH. You know, for a guy who thinks he knows so much, you don't know ****.