What type bov are you guy running with 18+psi of boost? Also where do you buy them and how much did you paid for? I want to use a bov on my blown 383LT1 motor. Any help is appreciate


Bruce

 

I'll be using one of these:

http://www.greddy.com/products/blowoffvalves_frame.htm

If you scroll down the page, you'll see a "relief valve". I'm not sure how this is used, but its function sounds the same as a BOV. I believe the units are off because 0.08 kg/mm2 (the low setpoint) equals almost 114 psi. I think the units should be kg/cm2, which makes the low setpoint 1.1 psi and the high ~28 psi. Maybe someone else can shed some light on this product.

 

Well I found quiet a few on the nets. But I am fall between the Apexi Bov and HKS SSQV

1)The Apexi bov have twin chamber and you can have an adjustable sound for extra loud.

2) HKS SSQV all it says is an aggressive sound. but not adjustable for loud.


Which one would you buy if you have to choose between the two?????? You input is appreciated.


Bruce

 

I am a firm believer that form follows function. I could care less about how a BOV sounds, only that it functions as efficiently as possible. After all, we don't decide on one only because it sounds "cool", do we? Of course, I can only speak for myself, so maybe you do???

I need one because when I let off the throttle at 23+ psig, I want that BOV to open as quickly as possible, period. And because I run two surge valves, this is the only time I want the BOV to open. Some clarification: My ATI surge valves do not open instantaneously when letting off the throttle. There is up to a one second (or so) delay. It's in that one second that I'm concerned that compressor surge will occur.

Willie

 

Stock blow off valve from a 90-94 DSM (Mitsu Eclipse, Plymouth Laser, Eagle Talon) should hold 18 psi. Turbo models only, obviously. Shouldn't cost more than $20 from a junkyard.
It doesn't sound as cool as the others, but it's a lot cheaper, and does the same thing.

 

It may hold 18 psi on a dsm, but 18psi on a DSM, and 18psi on a V8 are two different things. I doubt it will flow enough CFM to be fully effective, although I'm just guessing at that.

 

I don't think it would matter so much if it was a v8 or a DSM. It's not a question of how much air is flowing necessarily, it's how much pressure is being exerted on a valve. Besides, the Apex and HKS mentioned in this thread are popular among DSMers. Those BOVs are designed for low displacement engines, but can be used on larger engines, so wouldn't the same hold true for a 1g BOV?

BTW, you can "mod" the BOV to hold upwards of 25 psi. http://www.thedodgegarage.com/turbo_bov_mod.html

 

Timbr SS was talking about CFM, not psi... I think he is right also. The stock blowoff from a DSM is probably a dinky little piece and will pose a restriction trying to let off all that CFM that turbo is pumping in the intake pipe.

 

CFM isn't the issue here, it's the amount of pressure being exerted on the valve (psi.) The 90-94 stock BOVs aren't "dinky." The 95-99 DSM BOVs suck. If it's setup right, it shouldn't pose a restriction at all.

The $150 BOVs mentioned earlier in this thread work fine on DSMs. Even though the DSM flows less CFM, the amount of pressure being exerted on the valve is the same as it would be on a v8. If you're going to drop the cash on a HKS or Apexi BOV, just do it right the first time and get a Tial.

 

You are right, 18psi of pressure on a v8 is the same as 18psi on a I4 - so the valve that will work on one will also *hold* to that point on the other.

But once the valve is open there is a question of how long it takes to "vent" the boost. The 18psi on a V8 represents a much greater amount of air than on the I4, so through a fixed ortifice (BOV) and at a fixed pressure differential it will take much longer to vent out.

No if that's actually an issue or not i have no idea, but it definitely will take longer to vent.

 

True, but the same could be a problem with the HKS and Apexi BOVs that were mentioned in the above thread, as the HKS and Apexi units were not made to handle more than 30 psi of boost from 3.0 L I6 . I'm not saying a DSM BOV is necessarily the best choice, it's just as effective as the $150 Japanese brands and costs less.

I think the -best- choice would be to go with a Tial.

 

i would go with the Tial and just get it over with. I will hold alot of pressure and it will flow enough CFM for a 900 cubic inch BB with 6 turbos, 4 guns, and a rocket booster. The thing that I knew would happen as soon as I saw this thread was 1 someone will say something like "well that is for a 4 banger. A V8 is bigger and cooler and helps me make up for my ***** size, so it wont work." Well a 1G DSM BOV will probbaly do the trick but we dont know his whoel setup so all we can do is guess. I do know that a Tial will be more than enough and is a very nice piece. I also think its funny that I see alot of people on this board say that almost everything that has a 4 cyl is rice, however one of the first questions was what BOV makes the most noise or is the loudest. Those are all typical ricer comments. Well thanls for the spave and letting me rant.


Michael

 

*Cough*Godzilla*Cough*

 

I didn't see where anyone said that a V8 was better. When the DSM BOV was suggested, it seemed that the only cosideration was how much PSI it could hold. If that was the only thing that we needed to take into consideration, everyone would just run a solid pipe, cause we all know that would hold 100 PSI.

It didn't look like the CFM was being considered. 18PSI on a decent 383 is going to be at least 1000 CFM, most likely 1200+. Probably around 700rwhp or so. How much power/how many CFM is a DSM at 18 PSI?

I don't feel like looking up the numbers, but I'd guess that the same volume of air on the DSM at 18psi, would be less than 4psi, if # any at all, on a decent 383 LT1. (That's just an example, I'm content with my ***** size.)

When you're flowing that much air, coming off WOT, when the throttle blades close, that's a decent amount of pressure on the compressor. I would guess at least 50 PSI if you didn't have a BOV at all. You want to vent as much off that off, as quick as possible, to prevent compressor surge.

I'm not a DSM "tuner", and don't really know much about the 1G BOV recomended. I just doubt that a BOV designed for a ~200whp car is going to flow 1kCFM

Anyways, after spending $8k+ on a blown 383 LT1, I wouldn't be too worried about spending another $250 for a decent BOV.

 

Nobody said the 1g BOV from a DSM is the best choice. I was just stating that if you're considering over-priced Japanese BOVs like the HKS, Greddy, Apexi, etc, it might be a better idea to take a look at a 1g BOV. That's all. I mentioned that a TiAL would be a good choice IMO.