HKS BOV question

[V8SpankR]

I just bought an HKS racing bypass valve and I got a question.

OK,I know that the one vacuum fitting on the top of the valve goes to the line running to the manifold but there is also another fitting on the back of the valve and I need to know where that one is connected to or can I cap it off?
It came with kinda crude directions that show the line connecting to the IC pipe which would mean I would need to have a fitting welded onto my IC pipe,is this correct?

[BluByU]

Hmm, wish I could help you out Paul. My SSQV only has the one on top, so I'm clueless. Could that be for re-circulation?

[Pang]

yo alex hows the SS sound?

[ppalamara]

Top feed is intake plenum after the throttle body so it see's vacuum and boost
Bottom feed is boost only.
So in theory when your under boost you have the valve equalized and once off boost the excess boost pressure on the bottom feed forces the valve open along with the vacuum being placed on the top feed. Hope this helps.

[Chevy454]

you see the problem is you need a stock 1g bov

[Talonstylz]

Originally posted by Chevy454
you see the problem is you need a stock 1g bov

your a complete retard.... This ones for you http://www.jsalmi.net/finger.gif

[Chevy454]

Originally posted by Talonstylz
your a complete retard.... This ones for you http://www.jsalmi.net/finger.gif

RED X MASTER COMING AT YA, BAM YO!

[Chevy454]

and the stock valve can hold 20 fucking psi, stfu you pussy ass bitch.

[V8SpankR]

I of course have the stock valve but I want to be prepared to push over 20psi. The general concensus is it'll hold 18psi easily but can get a little leaky at any point over that.

So,I understand how the fittings work together but is it a necessity to run the boost only fitting to the IC pipe or can I cap it till I have a fitting installed?

[SleeperZ]

Pretty sure you can cap it Paul - that side of the valve already sees boost from leakage along the valve shaft. That connection just makes sure it's there, as far as I can tell - I just rebuilt one of those units myself.

[V8SpankR]

Thanks Nathan,this bypass valve is a really nice piece,not much bling factor since it''s not purple or any other color,just gray metal with the HKS logo on the top next to the big adjusting screw.

Should have it on this morning and we'll see how much louder it is over the stock piece.

[Chevy454]

me thinks you want the sound (you dirty ricer ;) )

you are venting it back into the intake track right ?

[shane]

I of course have the stock valve but I want to be prepared to push over 20psi.


Good luck!!!! i had that POS valve and it would NOT hold more than 15psi. Pure junk just like everything else HKS sells:guns:

[SleeperZ]

The unit I rebuilt I got from Shane. It was very leaky, and it would not stay open given a good vacuum. I had a new valve fabricated and fitted, and it seems to work better. I did check on the spring though - it's got a blue spring which is not the biggest one. We'll see what it will hold now (if I ever install it - my 1G DSM valve is holding 15 psi just fine).

[SleeperZ]

Originally posted by SleeperZ
Pretty sure you can cap it Paul - that side of the valve already sees boost from leakage along the valve shaft. That connection just makes sure it's there, as far as I can tell - I just rebuilt one of those units myself.

I should correct myself, now that I remember how it went together. With that lower connection tied to boost, you increase the sensitivity of the valve - if you cap it you should get the maximum boost holding-ability. The spring is the only thing that can keep the valve shut under boost (provided you hook the top connection to the intake manifold), so crank it down.

What did you pay for it Paul? I see this thing sell on eBay used for over $100.

[V8SpankR]

Originally posted by Chevy454


you are venting it back into the intake track right ?


Not a noob here,I've only been racing my DSM since '96 so I do know the obvious trapping of the DSM ricers.

[john]

Paul - leave it open to atmos. Is it this valve (http://jsalmi.com/carpix/640/IMG_0841.640.JPG) ?

Originally posted by V8SpankR
I just bought an HKS racing bypass valve and I got a question.

OK,I know that the one vacuum fitting on the top of the valve goes to the line running to the manifold but there is also another fitting on the back of the valve and I need to know where that one is connected to or can I cap it off?
It came with kinda crude directions that show the line connecting to the IC pipe which would mean I would need to have a fitting welded onto my IC pipe,is this correct?

[SleeperZ]

Originally posted by john
Paul - leave it open to atmos. Is it this valve (http://jsalmi.com/carpix/640/IMG_0841.640.JPG) ?

That's the one I'm talking about - yeah, you are right, technically it should probably be left open, but capping it won't affect it much - there will always be leakage around the valve shaft that should equalize the pressure to the intake tract.

[V8SpankR]

Yep,that's the one.

Now won't venting to the atmosphere cause the dreaded hesitation or stalling at lights? Or can I take care of that with the AFC?

I did get it installed and at the moment it's venting back into the intake and I do have a bit of hesitation inbetween hard shifts and is it supposed to make the "flutter" sound? I thought that was reserved for other BOVs and this one I thought just made the "pshhhht" sound. It is a bit obnoxious and sure gets the attention of anybody around you. :D

[SleeperZ]

So I take it is holding boost for you? Are you running your 17 or 18 psi? If it is fluttering, you might want to relax the top adjustment, or put boost on the lower hose connection. Ideally you want the valve to stay shut at maximum boost (duh..), and not to vent at idle, but to vent at a pressure differential marginally higher than where your car idles.

I'm not sure if you can put a needle valve inline with the lower hose connection to modulate the sensitivity or not... Once you set the main pressure with the adjuster, there must be a way to adjust the thing to vent properly (fully vent, no flutter) on a boosted throttle lift.

[V8SpankR]

So try reversing the boost connection and cap off the top one,right? Should I try relaxing the spring a bit first,I did tighten it down pretty good before I put it on.

[shane]

Vent to atmosphere is just fine, a BOV should NOT be open at idle. Set up right it should only open under very high vacuum, higher than what the car idles at.

[V8SpankR]

Originally posted by shane
Vent to atmosphere is just fine


DSMs have an issue with venting since the ECU is compensating (expecting) for the air coming from the bypass valve,I tried venting the stock one for fun and it sounded cool but would die at idle or idle very crappy.

[SleeperZ]

Originally posted by V8SpankR
DSMs have an issue with venting since the ECU is compensating (expecting) for the air coming from the bypass valve,I tried venting the stock one for fun and it sounded cool but would die at idle or idle very crappy.

That's because it's venting (albeit slightly) at idle. And do not cap off the top hose connection - that HAS to connect to trigger the valve.

[exciv2000]

hey paul, you'll have to show me where your testing ground is sometime... I need some NOS tuning and need some open space not around cars and houses and shit. Lemme know.

[shane]

DSMs have an issue with venting since the ECU is compensating (expecting) for the air coming from the bypass valve,I tried venting the stock one for fun and it sounded cool but would die at idle or idle very crappy.


Read my post, it should not be open at idle. Its not a DSM issue its a MAF/AFM issue. But like i said if you have it adjusted right then it will be closed at idle and your ecu will not have anything to compensate for.

[V8SpankR]

Originally posted by shane
Read my post, it should not be open at idle. Its not a DSM issue its a MAF/AFM issue. But like i said if you have it adjusted right then it will be closed at idle and your ecu will not have anything to compensate for.

Gotcha',thanks.

I'll be fiddling with it shortly.

[V8SpankR]

OK,well venting isn't working,the car stall when I stop. What on the AFC can I adjust to help it idle.

I also am hitting a flat spot after a hard shift,the car feels like it's ready to fall on it's face and then it takes off hard.

I'll be cleaning the IC out tomorrow and I'll have all the piping off tomorrow since I need to check the turbo for any oil leaks and monitor how much oil is blowing into the IC.

[91talon16gsi]

Iv'e had my 16g at 17psi and my bov holds boost fine. I actually took off the part where the boost comes out when you let off the gas so you can hear the woosh sound better. Then I rigged it up so air wouldn't be sucked in while it is idling or when decelerating,preventing stalling. Its and easy project and only cost $7.

[V8SpankR]

So,how about some info?

[stu]

Sounds like a check valve to me.

[SleeperZ]

Originally posted by stu
Sounds like a check valve to me.

Nah, sounds like he just removed the bypass hose, blocked the hole off in the intake, and tightened the spring so it doesn't leak at idle.

[J_Smuggler]

Originally posted by shane
Pure junk just like everything else HKS sells:guns:

I agree

[91talon16gsi]

Here's how I did it(dsm 1g bov)...I first bought a spring and a ruuber drain plug. You will have to a attach the spring to the plug and then hook the spring to the inside of the bov. There should be a small rod in the center of the bov. Thats what you attch the spring to. So now at idle the plug is snug were the bypass hose would go on the bov. With the spring it allows the plug to come out when you are on boost and you let off the gas(accelerator). Then the spring will pull the plug back into the bov allowing no boost leak at idle. Works pretty good and it's a cheap mod to make ya car sound better.

[SleeperZ]

Originally posted by stu
Sounds like a check valve to me.

Yep, you're right. That's exactly what it is. ;)

[V8SpankR]

where would the check valve be? Is there a fix?

[SleeperZ]

Originally posted by V8SpankR
where would the check valve be? Is there a fix?

Paul, we are talking about two different valves here. 91talon16gsi is talking about a ghetto mod to a stock DSM valve to keep it from leaking at idle, using manifold vacuum to suck a plug into the dump. The HKS valve should be adjustable where it doesn't leak. But it's a big valve, metal on metal, and it will still leak a little bit no matter how tight it is. Personally I'd still vent the thing into the intake because I don't like noisy blowoff (RICE!), and then it's irrelevant if it leaks a little; it won't hurt idle and it won't suck debris in.

[91talon16gsi]

It works really well. My bud did it to his 87 mitsubitshi starion and it works great.

[quick92gsx]

I STILL HAVE MY STOCK BOV AND I CRUSHED IT AND IT HOLDS 22-25 PSI JUST FINE I PUSH 16PSI ON STREETS AND 20PSI RACING

[exciv2000]

Originally posted by quick92gsx
I STILL HAVE MY STOCK BOV AND I CRUSHED IT AND IT HOLDS 22-25 PSI JUST FINE I PUSH 16PSI ON STREETS AND 20PSI RACING

STOP YELLING stupid dickweed noob

[V8SpankR]

Originally posted by quick92gsx
I STILL HAVE MY STOCK BOV AND I CRUSHED IT AND IT HOLDS 22-25 PSI JUST FINE I PUSH 16PSI ON STREETS AND 20PSI RACING

It works with some and not with other;crushing isn't an exact surefire mod.

[SleeperZ]

Not to mention at higher boost levels you have more charge to vent that may exceed the valve's capability to flow -- especially since you restrict the valve travel by crushing it. The HK$ will not have that issue.