Question?

[500hpskyline]

Legally i know Blow Off Valves not plumb back are Illegal

But Performance wise which is better? Is There A Difference?

Plumback Or Not?

Thanks Lee

Edited April 6, 2008 by 500hpskyline

[jenkies]

this has been debated time and time over.....go the plumback

Edited April 9, 2008 by jenkies

[Imtorqing]

Legally i know Blow Off Valves not plumb back are Illegal

But Performance wise which is better? Is There A Difference?

Plumback Or Not?

Thanks Lee

Performance wise as in how it operates ? the answer would be no difference unless the plumb back is restrictive.

Much like a screamer pipe off of your wastegate being plumbed into your exhaust(Not a screamer pipe if plumbed in lol cuz it doesnt scream), they are in theory for this scenario the same. The only reason for not plumbing them in is People love the sound.

My blow off valve is hidden and has a high pressure spring, so it doesnt go off unless im booting it. Thus if im booting it and the police see and hear me then im in trouble anyway but it helps to stay under the radar when driving normally compared to the gay little tweeters that so many tend to love.

Hope it helps.

P.S I think it has been extensively discussed that a BOV has minimal if any performance advantage.

[Imtorqing]

double post by accident lol

Edited April 6, 2008 by Imtorqing

[sinistaGTR]

in terms of a screamer pipe.... actually it does help performance if its an external gate setup with big hp cause of the exhaust flow but for most its just a sound thing.

[500hpskyline]

Performance wise as in how it operates ? the answer would be no difference unless the plumb back is restr.....

so with the screamer i have external 44mm tial WG and screamer pipe is that or is that not better than it plumb back?

AND IT f**kIN SCREAMS!

[Devils_Advocate21]

legak vs non legal you make the choice i say plus both have been covered esp the bov extensively in the Forced Induction area in the forums cheers

[TTT]

are you asking about a bov or wastegate?

bov atmo venting = no performance gain and many headaches on an AFM equiped car.

wastegate atmo venting = "apparent" gain in performance.

However, I'd like to see the dyno sheets of someone with a 3-3.5 inch exhaust who has a split dump pipe where the wastegate pipe joins the rest of the exhaust way down the line (like a CES style dump pipe), compared to when they change the dump pipe to a split dump with atmo venting wastegate pipe.

I'd suggest that apart from sound, there will be no change in power.

[psi]

Lots of people have lots and lots of stuff to say about BOV's,

now, when u ask performance.. do u mean:

A: how much air the BOV moves while it open, or

B: the perfomance of the vehicle as far as horsepower gain/loss?

Most off-the-shelf BOV's are poor or just useless as far as air flow is concerned.

When u consider how much air your engine consumes at high revs, then how long the throatle is shut while u shift gear. it scary! I know at 6500rpm my engine sucks in about 200L of air in a second. so if the throatle is shut for one second, to do the job right, i would think the BOV needs to move 200L or air in a second..

does that cheap junky thing most buy do that?

Now think about why turbo cars are fitted with BOV's to start with from the factory. They fitted them to make the car quieter and to help maintain a smooth ride during gear shift, not jumping or poping or fluttering. I am sure all car makers know what works, and would have spent lots of money double checking it, so copy their lead!

As for car performance.. I am yet to see anybody who can prove any of the following:

A: that fitting a BOV makes the car faster or gain HP

B: fitting a plumb back or vented BOV increases HP

C: swapping from one BOV to another kind of BOV increases HP.

D: a flow bench test to prove how much air the BOV flows! Ask any retailer.. they dont know!

but then again, I may be wrong..

[Col-GTSX]

I ran a HKS SSQV simplly cause i wanted a "pull" type valve...

When you run huge boost you can experience boost leak via the BOV on the usual "push" type valves so I went SSQV simply for redundency...

You can also get a plumb back fitting for the ssqv if you want a pull type but want it to be legal...

Remember either way you go, have the car tuned to suit...

So technically I had a performace reason for a 'atmo' valve...

[Owgasm]

So, i've got twin ssqv, wheres this "plumb back fitting" whats it do?

[Col-GTSX]

Its a sleave you can buy from ebay that fits into the mouth of the ssqv and gives you a sleeve you can clamp a hose onto...

You loose the noise completelly however as the fins that create the whissle are removed to have this part fit...

[Black Ninja]

Its a sleave you can buy from ebay that fits into the mouth of the ssqv and gives you a sleeve you can clamp a hose onto...

You loose the noise completelly however as the fins that create the whissle are removed to have this part fit...

I can get it locally and i guess they are still in stock. Just pm me if you want and i can hook you up...but as col said, you will loose the whistle sounds..

[53XYN]

plumback is safer option plus you wont get defected and still retain the bov "swoosh" sound that comes from your airfilter

[500hpskyline]

well i got a turbosmart supersonic not plumb back with power fc so i have my afm and after tune i have this like over fueling or sum shit where if im am at 4000rpm or high rev say hit the clutch it will drop to like 200rpm-400rpm and go buh.....buh....buh...buh..buh.buhbuh back to normal idle sometimes it stalls my tuner says its cause my BOV is not plumb-back is there another way to go about it instead of moving bov under afm intake.

thanks Lee

[Oblivion]

plumb back system duct the air (on a proper set up system) back into the turbo intake, it is suppose to reduce lag between changes, though just having one reduces the negative pressure on the turbo. Some people dont like them because they can also be the source for power loss....still working that one out though.

[dano4127]

well i got a turbosmart supersonic not plumb back with power fc so i have my afm and after tune i have this like over fueling or sum shit where if im am at 4000rpm or high rev say hit the clutch it will drop to like 200rpm-400rpm and go buh.....buh....buh...buh..buh.buhbuh back to normal idle sometimes it stalls my tuner says its cause my BOV is not plumb-back is there another way to go about it instead of moving bov under afm intake.

thanks Lee

I have got the same problem at the moment with my Tial 50mm BOV it is because the spring is too weak you need to get a tougher spring and most of your problem will o away, also adjust your driving style to suit

dont come up to the lights full song then clutch/break to a stop, what you need to do is run down through the gears and motor ub to the line

[500hpskyline]

I have got the same problem at the moment with my Tial 50mm BOV it is because the spring is too weak you need to get a tougher spring and most of your problem will o away, also adjust your driving style to suit

dont come up to the lights full song then clutch/break to a stop, what you need to do is run down through the gears and motor ub to the line

Well of course ive had to change my driving style a lot especially after brass button clutch went in it was a pain in the arse to get use to but sorted now but still want it fixed so u reckon harder spring in BOV? well ill have a sniff around with that and see what i can do

[psi]

harder spring does help.. the high vacuum loads pull the valve partly open.

if you cant find or buy one, you can shim it!

I have seen coins used on shitty little BOV's before, and they do work.

So, if nothing else.. go washer hunting