What experiences do people have with fitting Blow off Valves?

samlux · Nov 16, 2020

Hi, I have a 2015 Levorg GT-S imported from Japan and I want to fit a Blow off Valve to it but I would like to know if my car will require a remap for it to run properly. I understand for any performance increase etc it will require a remap but until I look into doing that can I fit one and will the car accept it. Thanks in advance.

Togh · Nov 19, 2020

I was buy this ... https://www.perrin.com/shop/turbo-accessories/subaru-recirculating-bov its noc clasic blow but i mean will be better ... why ..read specs... should be come next week...

Marek Slovakia

Luke Rado · Oct 31, 2021

Bump on this.
Has anyone fitted? Obviously will only get chu chu in sports mode, as CVT in lineartronic will hold throttle wide open… but I’m curious because if we can’t add too much by way of horses maybe a few extra Rumbles (exhaust) and whistles (BOV) will help with race car feels haha

Togh · Oct 31, 2021

Luke Rado said:
Bump on this.
Has anyone fitted? Obviously will only get chu chu in sports mode, as CVT in lineartronic will hold throttle wide open… but I’m curious because if we can’t add too much by way of horses maybe a few extra Rumbles (exhaust) and whistles (BOV) will help with race car feels haha

Me...

Luke Rado · Oct 31, 2021

Togh said:
Me...

Can you please elaborate?

shmity · Oct 31, 2021

The car comes with a bypass valve already fitted (a bpv is a bov that vents back to the intake rather than to atmosphere). The car is also a MAF based system, so you will absolutely need a tune for it to run properly. Even then it can only compensate for some of the richness you'll experience and can't fix all of it. You're going run rich either way, it just depends how much and how much you hate your spark plugs.

Luke Rado · Nov 1, 2021

shmity said:
The car comes with a bypass valve already fitted (a bpv is a bov that vents back to the intake rather than to atmosphere). The car is also a MAF based system, so you will absolutely need a tune for it to run properly. Even then it can only compensate for some of the richness you'll experience and can't fix all of it. You're going run rich either way, it just depends how much and how much you hate your spark plugs.

Thanks mate this is the info what I was looking. Cheers

Guvna · Nov 5, 2021

samlux said:
Hi, I have a 2015 Levorg GT-S imported from Japan and I want to fit a Blow off Valve to it but I would like to know if my car will require a remap for it to run properly. I understand for any performance increase etc it will require a remap but until I look into doing that can I fit one and will the car accept it. Thanks in advance.

BOV's don't require a re-tune, but it will run a lil rich if you vent it to atmosphere as the air ammount has already been measured. Can foul spark plugs and over time burn out the cat as the unburned fuel burns very hot in the cat. But no tune is needed.

nicodache · Nov 5, 2021

Guvna said:
BOV's don't require a re-tune, but it will run a lil rich if you vent it to atmosphere as the air amount has already been measured.

Doesn't the same happen with BPV ? Air bypasses cylinders too, and ends up in the exhaust pipe.
And anyway, BOV or BPV typically open only when there is over pressure in the intake manifold (because we suddenly close intake butterfly), which isn't that frequent overall. spark plugs would get cleaned over the next few seconds once we start accelerating again, no ?

Guvna · Nov 5, 2021

nicodache said:
Doesn't the same happen with BPV ? Air bypasses cylinders too, and ends up in the exhaust pipe.
And anyway, BOV or BPV typically open only when there is over pressure in the intake manifold (because we suddenly close intake butterfly), which isn't that frequent overall. spark plugs would get cleaned over the next few seconds once we start accelerating again, no ?

G’day Nico, Bypass valves differ from blow-off valves in that they don’t vent any air to atmosphere, Instead, they plumb the air back into the intake pipe (not the exhaust) before the turbo but after the airflow sensor so the ecu isn’t confused about how much air it has measured and then it can supply the correct amount of fuel instead of too much. Spark plugs somewhat clean themselves but over time they clog up, just like all plugs do, running rich just makes it happen sooner.

nicodache · Nov 5, 2021

Damn, I got mixed up between BOV to atmosphere and BOV to exhaust pipe #facepalm.

cakezxc · Nov 24, 2021

Luke Rado said:
Can you please elaborate?

Blitz VD universal fitted here. Doesnt matter if what mode youre in. As long as you were in boost and you let off its gonna go choo choo.

Tune for BOVs arent absolutely necessary but certain changes made to tip in and runoff fueling related maps CAN help with the momentary rich condition when you let off. Not many tuners bother with that, but some do. Only harm it can do is a) sooting up your plugs, and b) possibly cooking your cats after years and years of that momentary rich condition.

mando345 · Dec 17, 2021

Luke Rado said:
Bump on this.
Has anyone fitted? Obviously will only get chu chu in sports mode, as CVT in lineartronic will hold throttle wide open… but I’m curious because if we can’t add too much by way of horses maybe a few extra Rumbles (exhaust) and whistles (BOV) will help with race car feels haha

I got installed a Booma BPV valve to replace to stock one, for BPV no tune needed. I do get turbo flutter or a light whisle at 1 Bar, anything lower you cant really hear a thing, but I did notice that the car was boosting a lot faster quicker which is nice and made it a bit more peppy.

Robsyuk · Jun 17, 2022

Can I see a video of your valves dumping please.

mando345 · Jun 17, 2022

Been wanting to do one from long time but i wanna order a mic for my gopro so it will ease up on the wind noise, but even then it may not be too loud

nicodache · Jun 17, 2022

give it a try already, and if the gopro picks up the wind to much, then we'll wait for the mic

Robsyuk · Aug 22, 2022

@samlux I'm in Milton Keynes and should have my import by October. Did you ever get a dv or a map to run uk fuel?

samlux · Aug 23, 2022

That's awesome mate, I hope it comes around quickly for you! I have fitted a GFB variable BOV but I only have it venting about 10% if that, otherwise the car doesn't like it. I have plans for later this year to have it mapped onto UK fuel still at 300bhp and to get the BOV properly tuned in so I can open it fully along with getting the speed limiter taken off. @Robsyuk

Luke Rado · Aug 27, 2022

I have a GFB deceptor Pro 2 (electronically adjustable) so I can vent “off road” and plumb back to stay legal. It’s great. I love the Choo Choo and in tandem with the ADR Varex (x force) exhaust is a great combination of noises… I am far less worried about the FA not having that boxer rumble now that the BOV/exhaust are doing their thing… next thing is to add more induction noises…. To date no issues with plugs or running rich in my 2.0L, been about 10’000kms/6months approximately. About to take it in for a service so will see what they say. Up to a major-ish too I think…

Minimayhem · Aug 28, 2022

Luke Rado said:
I have a GFB deceptor Pro 2 (electronically adjustable) so I can vent “off road” and plumb back to stay legal. It’s great. I love the Choo Choo and in tandem with the ADR Varex (x force) exhaust is a great combination of noises… I am far less worried about the FA not having that boxer rumble now that the BOV/exhaust are doing their thing… next thing is to add more induction noises…. To date no issues with plugs or running rich in my 2.0L, been about 10’000kms/6months approximately. About to take it in for a service so will see what they say. Up to a major-ish too I think…

I'm thinking of getting one of these. Difficult to fit?

What experiences do people have with fitting Blow off Valves?

New Member

New Member

Member

New Member

Attachments

Member

New Member

Member

Active Member

Active Member

Active Member

Active Member

New Member

New Member

Active Member

New Member

Active Member

Active Member

New Member

Member

New Member