To Bov Or Not To Bov

[mctwistuk]

After the meet on Thursday night and hearing a few of the cars with BOV's it has got me thinking do i want one??????????

Have never really wanted one before but now i am getting the itch to buy one. I know a lot of people run the HKS type but these are quite expensive. What is a cheapper alternative and what are the implications of fitting one?

[cullenmin]

Occasional pops and bangs during a spirited drive, only if you've got a full de-cat also

[wimpy]

  Cullenmin said:

Occasional pops and bangs during a spirited drive, only if you've got a full de-cat also

Bailey's are not bad for cheapness or forge. but you get what you pay for. Have a look on flebay sometimes get a good deal on there.

Iain

[thewelsho]

  mctwistuk said:

... what are the implications of fitting one?

The annoying PSSSSHHHHHHHHTTT every time you change gear! I'm sure it would sound cool to start off with, but after about ten minutes of that, I think it would drive my up the wall, hence the reason why I don't have one! Though I have to be honest and say I did think about it!

[Carson]

What year's your car mctwistuk?

Instalation is simple enough on all years.

Ive got my old blow off valve in perfect condition! 50quid and its yours, ill fit it for you if your not car orientated

EBAY - My old valve

chris @ paisley area

Edited February 9, 2008 by Carson

[oobster]

I had one on my WRX for over a year - car ran better once I put the standard one back on.

My understanding is that your car will run ok if it's mapped with a VTA valve on, but if not the car can overfuel slightly resulting in some petrol mixing with the oil & thining it out. Or so I understand it anyway, from reading posts on here +SNet.

I changed the oil in mine every 5K when I had the VTA on, just in case.

[p1ggm]

hks all the way, its the best by miles, i would say no to a bailey one tbh, turbo smart, turbo xs ones are good

[dipsy]

I can hear the standard one more after fitting a green panel filter

[Carson]

mates got the baileys, his car over fuels

[shane]

  Dipsy said:

I can hear the standard one more after fitting a green panel filter

I've had a GFB on my WRX for about 3 months, it's a 50/50 so not massively loud. It's a bit annoying sometimes when you are trying to drive normaly and it goes off during a gear change, if you change gear slowly and with a light throttle it is possible for it not to go off. It does sound great when blasting it through the gears though.

[gus the bus]

Wouldnt put one near any of my Subaru's

[ally-b]

I've been asked a few times what dump-valve I have on mine as it has it makes the ptssshhh sound

It is the standard re-circ one - but you can hear it clearly cos of the APS cold air kit

Al.

[mctwistuk]

  Carson said:

What year's your car mctwistuk?

Instalation is simple enough on all years.

Ive got my old blow off valve in perfect condition! 50quid and its yours, ill fit it for you if your not car orientated

EBAY - My old valve

chris @ paisley area

thanks for the offer. By the sounds of it the car is better to keep the standard one on it. Will need to think about this more.

Chris

[scientific steve]

i had a bailey one at first and found it was pretty bad at motorway speed (70 ish)

as it would leak and sound like it was just on the boil (if you know what i mean)

now have a hks one fitted and you can get away with out it giving the pphhhhhhssssssst at lower rpm

as it has a sronger spring and is suited for higher boost

[Carson]

Just noticed your footer, your car wouldnt take the my valve anyway bud.

New age's have a standerd valve that helps presure issues the old classics had so id be happy with yours,If moneys no object get the cold air induction kit and that should spice up the sound? Should sound like this?

correct me if im wrong

[johnnyr6]

I fitted an apexi ind. kit and you car hear the standard recirc working.

I wouldn't put a bov on my car unless my set up dictates one ( e.g. twisted turbo with external wasegate) and it's been mapped to suit.

Johnny

[mctwistuk]

  ally-b said:

I've been asked a few times what dump-valve I have on mine as it has it makes the ptssshhh sound

It is the standard re-circ one - but you can hear it clearly cos of the APS cold air kit

Al.

would love a CAI kit but can't afford the remap the now although APS say that the 60mm one is ok without remap. Could this be true???

[dipsy]

Mctwistuk send Andy F a email about CAI kit and remap he will keep you right

Edited February 9, 2008 by Dipsy

[mctwistuk]

  Dipsy said:

Mctwistuk send Andy F a email about CAI kit and remap he will keep you right

just sent the master an email and await his words of wisdom

[thewelsho]

  Dipsy said:

Mctwistuk send Andy F a email about CAI kit and remap he will keep you right

Yes, and I'll bet he will advise you against it.

[Boyakasha]

  ally-b said:

I've been asked a few times what dump-valve I have on mine as it has it makes the ptssshhh sound

It is the standard re-circ one - but you can hear it clearly cos of the APS cold air kit

Al.

Al this is exactly what I was going to say, the sound of the APS CAI on my MY07 STi is awesome, you don't need an aftermarket BOV as the standard one sound great. I used to have an HKS SSQV on my MY03 STi which was nice but I'll be sticking with the original BOV now.

[wilky]

If your hell bent on fitting a dumpvalve then do it just before a remap and in most cases it can be taken into account during mapping giving minimal ill effect.

On a factory ecu map the car is mapped to take into account the fact that when the engine "dumps" boost the air which has been seen by the ecu will be returned into the system again, and the fuelling set up for this. When you dump that air into the atmosphere to get the desired sound and hard on, and its fuelling has not been adjusted to take this into account the ecu doesnt know the air isnt going back into the system, supplies fuel for it anyway and the car runs rich momentaily hence pops and bangs. In the worst case scenario under full load wide open throttle when you change gears and dump the boost, the excess fuel can cause borewash, ie the excess fuel doesnt ingnite runs down the cylinder wall into you sump and dilutes your oil. Its not much but many WOT gear changes and many wee bits of fuel soon add up. This was happening on a car I know and refitting the standard DV solved the issue.

[shane]

Surely this is less likley (<50%)with a 50/50 BOV ?

[colzo]

This subject has been done to death on ScoobyNet and the outcome is always 'don`t bother'. I had a Forge one on my P1 and thought it was 'cool' at the time of having it, but it was also jerky when accelerating. Mike Wood from Prodrive said its a big no no as your standard one is fine unless your going for big BHP.

[mctwistuk]

  Wilky said:

If your hell bent on fitting a dumpvalve then do it just before a remap and in most cases it can be taken into account during mapping giving minimal ill effect.

On a factory ecu map the car is mapped to take into account the fact that when the engine "dumps" boost the air which has been seen by the ecu will be returned into the system again, and the fuelling set up for this. When you dump that air into the atmosphere to get the desired sound and hard on, and its fuelling has not been adjusted to take this into account the ecu doesnt know the air isnt going back into the system, supplies fuel for it anyway and the car runs rich momentaily hence pops and bangs. In the worst case scenario under full load wide open throttle when you change gears and dump the boost, the excess fuel can cause borewash, ie the excess fuel doesnt ingnite runs down the cylinder wall into you sump and dilutes your oil. Its not much but many WOT gear changes and many wee bits of fuel soon add up. This was happening on a car I know and refitting the standard DV solved the issue.

Thanks for the words of wisdom Callum hey are much appreciated. Think i am going to wait and get either an RCM induction it or an APS CAI and fit it just before my remap.