This is a common myth. The system is dependent on 1) the TPS signal, and 2) the BOV itself. Modern fuel injection system do a fuel-cut on decel to 1) save gas, and 2) alow the revs to drop faster; the fuel-cut decel should override any fuel delivery (issues). If the TPS is slightly off, it'll keep shooting fuel on decel - this is how you get the popping on decel or in between shift. If the BOV doesn't seal fully (which it sounds like this is the case in this video), you get an intake vacuum leak - what were the vacuum #'s before and after the BOV install? Was it the same? I've seen plenty of BOV's that leak on WRX's / STI's... Making a BOV that 100% seals at idle makes it more expensive to produce. If the BOV is sealed 100%, the system is closed, and your idle should be identical to before - the fact that you're running rich means something else has changed. This is why some people have no issues, and why some people do have issues.
I was gonna say I bought my 19 wrx used that came with an HKS BOV and it’s closed system, i didn’t think it had a MAP for it installed already but I don’t have any idle issues what so ever since purchase. Seems to be working A OK. Still need to get an AP for her but other than that no issues still 🤞🏻🤞🏻
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I'm not that sure. I have a Suzuki Swift Sport ZC33S (from 2018), and I installed recently (a month) the HKS SQV IV valve and I'm experiencing some of the symptoms that he says. Today I'll mount the recirculating tube, to see if that mitigates the lagginess and stuttering in very low revs, like when I'm in the middle of heavy traffic. Saddily I'll lose the high pitch sound, but in the long run I prefer to not to damage the engine.
Hey man, there is no way that it would make a difference running that low RPM, The BOV only opens up to let the air out when the boost pressure is above 0 (Hence the BOV sound). Anything below 0, you should not even notice the difference because it's a closed system... So with all do respect, what you are saying does not make sense. If its open below 0, that would indicate a boost leak.
especially when running something like the GFB TMS Hybrid. Zero chance you’re gonna mess up the closed loop system if you’re setting the spring tension correctly. That’s literally it.
Idk man, I know science is science but I’ve owned 3 Subaru’s, rocked a BOV and OTS tune on all 3, put easily 75k+ miles on all 3, and had 0 issues related to the BOV. All cars were tested and healthy at time of sale. Maybe I’m just the lucky statistic 3 times over. Nice video and very informative though, keep up the good work
I've seen some cars respond different using OTS Tunes, if you have a higher quality valve it would mitigate out some of the leaking issues that other valves have had.
Right. I just installed a fully atmospheric bov on my 2018 sti and I didnt have an of these issues that smeedia has. Maybe theres some underlying issue causing the knock in this video? I installed mine after watching and did little revs like this and not a single issue. Maybe its cause his bov spring was too loose and was by passing even the slightest bit of pressure? Maybe it's not having that long pipe on the ic piping for the stock bpv location? But I dont think that knock issue is directly because of installing a vented vs recirc valve.
@@enemen8 The car is not designed for it, doesn't mean you can't get away with it. Typically the Supreme crowd or "younger" crowd throw them on without knowing anything, go get a tune and ask for the "Can i get a dope crackle n pop tune with a touch of flames out the exhaust, bruh?"
MAF measures the mass of air that enters the engine. Speed density calculates the amount of air that goes in the engine by measuring pressure, manifold air temp and rpm. You must use a float valve style BOV that does not stay open under vacuum. If so you simply need to change one number in the tune. His engine is actualy over correcting for running lean because its sucking in air at the BOV.
I did a ton of reading about speed density vs maf tuning for my lt1 corvette motor. Same concept different platform. I’ll see if I can find the link, it’s a ton of relevant information to the topic
See, its a missconception. You can use a twin piston/diaphragm type atmospheric bov on maf setups and they work as perfect as they do with the recirc valve. If you were car guys youd know this... Ive run a loud bov on every turbo car ive had and all being maf setup. Do some research and stop talking shit.
Been running my bov for 18 months on 380 HP wrx. No issues at all.. I stay up on maintenance, and plugs look normal. I recommend getting one if you want.
Did you get produced with it on the car? The major issue of it is using a BOV on a Stock car or one with an OTS Map which already have their own issues with them.
I have an fully recirculating hks bov paired with a cobb big sf intake. E-tuned by William Knose at Delicious Tuning by the way. In my opinion, this is the way to go if you want those spooly boy noises. The stock airbox muffles alot, so you can certainly hear the bov noises through an upgraded intake. Side note, my hks bov is a 13 year old original version from 2007, that was still brand new in the box that I never used for a prelude build I never finished before joining the Marines.
I just installed the AEM chargepipe today and realized at the end that those suckers didn't include the recirculation hoses as the AEM relocates the BPV on top of the engine...same situation...car runs way rich with CEL P0170, car stalls when coming to a stop...smell of rotten eggs...waiting on delivery of the hose...thank for the video this clears things up...i swear you da best! And the only youtuber I came across that responds the same day lol....Bless you bro
"I'm scared because the rpms are dropping low" probably because the ecu is trying to re learn everything. What exhaust is that? Kinda sounds like dookie
Also you said that the extra fuel would get into your oil as it ran down the cylinder wall. You would have to be running insanely rich to have left over liquid fuel in your combustion’s chamber(like 5:1 gasoline). Also your wideband afr gauge on the right side of your steering wheel was reading anywhere from 14.5-15.1. Not rich at all as the stoichiometric air fuel ratio of gasoline is 14.7:1
Id guess you done have it setup right. My GFB Hybrid BoV was installed by a master tech at a Subaru dealership and I have 0 problems. Its running about 50/50 recirc/vta. Also its only going to "run rich" for a split second during a high rpm shift. If anything that split second of rich is going to help vs engine knock. Its been on the car for 2 years (35k+ miles).
I just bought a side project car and its a used 2013 WRX STI Sedan Sporttech usualy they go for around 17K + I got it for 10K 1.has very small body work to do (only minor rust spots) 2. needs a new paint job 3. The car runs but dosn't run well. Coming from the dealer that I bought it from every time I hit the stop sign or light that choking issue 9:01 happened. I stalled at 3 stop signs.... Got home opened up the hood and the air circlation hose is cut and plugged... stock BOV... So I got on to watch videos on Bypass valves and blow out valves and I want to say thank you! Easy fix just need to get another hose! Thanks for the info @Smeedia
Hey Tanna, it's UK Subie guy. Waw, it's been a long time from this video, & You buying my dream car for the next chapter of the channel. I really like seeing the influence you give out in every video, no matter how hard the next part instal/removal. There are so many Great car covered ytube channels adopting your style & weeding out the fake weekend mechanic. Gracias mi amigo 🇬🇧🤘🤘🤘🤘
If you setup BOV correctly the car will not idle or run ANY different, unless you did it wrong then it will idle differently, or its a POS like that valve, If you can smell fuel or it runs different you done screwed up and not installed it correctly or its not adjusted correctly, during idle the valve is 100% closed and doing nothing so wont effect anything. (High quality valves like GFB Hybrid are the best and cant even leak even if 100psi boost) Makes almost no difference it only runs lean for 0.15 - 0.3 seconds when you let off the gas and as you are not making power it does not matter if AFR's goto full rich If coasting down a hill in gear AFRs are meaningless as injectors are shutoff during coasting. Even the guy who started the rumor in the UK admitted to it after like 15 years that he was just making it up as he hates all the ricer Subarus going around making blow off noises (Ricer/Racer boys) It all started from him and was just a joke, Just like the DR who joked about Vaccines causing Autism in a paper he wrote and accidentally started the now stupid idea people have that its real, Even year later when he said it was just a joke in the paper he wrote people wont believe him and say he must have been paid out by Big pharma. Put it on dyno and watch the lean condition is so short if you blink you WILL miss it as human eye takes .25 seconds to blink so easy to miss a rich condition that last .15-.3 seconds. If you are serious about tuning should be replacing the plugs every 10,000KM as they will be copper spark plugs which are best for fuel burn and so on.
Big ups to Tanner for willing to use his car as a guinea pig to show what not to do. Alot of people still dont understand a stock MAF setup vs a MAP setup.
The BOV isn't what was causing your issues at idle. How could it when there is no boost to blow off? Regardless, you can't tune for a BOV. I get really tired of telling people that. There is no special table for "WOT release" or anything. They do slightly increase how rich the car runs for that brief moment when letting off the throttle, more pops and bangs, which in turn can hurt the cat and turbo since those explosions are happening nearby.
With Speed Density, there is no tuning you can do either. It's just that the reference of MAP is a lot closer to the injectors than the MAF is, so there is a lot less time of fuel squirt at WOT release. Anyway, I am so sick of BOV arguments, and this video makes it worse. 175k views and counting ;(
@@sssnake2332 Thanks for the explanation! I bought my '18 STI a little over a month ago which came with a GFB bov, and I've been reading forums on the subject ever since. I don't have any of the issues that Smeedia was having in the video so I wasn't too sure what to think. I love the sounds my bov makes, but I'm not going to keep it on at the expense of my cars health... :C RIP 😢
This video makes me laugh lol “the car smells rich “ I installed a hks bov on my sti and had no problems honestly it’s running great, Talk to your tuner.
As long as your not on an OTS Tune with the BOV its not a huge issue. A protune fixes a lot of the out the box issues associated with just slapping one on
Smeedia I believe I’m on a OTS tune at the moment, I have to talk to my tuner but it’s so weird that your car has symptoms like that. Have you had any updates on it?
I pulled the BOV off the car after the vidro and stayed with the bypass valve, im going on a hybrid speed density tune so because I am still utilizing some of the MAF I'm sticking with thr BPV. But based off of what I did im sure the BOV was leaking air causing idel to be all screwed
Smeedia I would like to come help you maybe the rubber inside the inserts were not tighten down? Or the rubber seal bad? Also my kit came with a recirculating kit with my hks bov, if you want you can try it on your car if you wanna run the hks!
I only used the BOV as an instructional piece for the video to demonstrate the effects of an out the box BOV on an OTS TUNE. But greatly appreciate the advice!
Great Video! A few years ago I purchased a RFL blow off valve, had it installed with the idea it was a plug and play, I was so wrong. No matter how many washers, ( how it said to adjust ) caused the car to stall at every stop, and turn the tail of my car black from running too rich. To make a long story short, it’s back in the box and sitting in my trunk. I wish I saw your video 3 years ago!
Glad that you got it sorted out, and some cars react different than others from what I've seen most think that BKVs are plug and play but so much more to them than one thinks. Appreciate the added sorry and kind words!
I should’ve watched this video before I almost messed up my engine..got a 2004 wrx and installed this bov the whistle so freakin nice but after few months the sounds started to go down until its gone and after that i startedto hear like fluttering noise from my engine and dont know wth is going on even my mechanic got headache i gave him tylenol..please listen to this guy and dont install that piece of crap.🤓
This was a good laugh. I ran a vent to atmosphere bov on a decently modded, not built 7 bolt 22psi 2g awd dsm from 60k-280k miles. To counter this, I ran a k&n style breather after the maf. My af gauge read super rich before the breather. Came back down to not so rich and good levels after. If I did it again, I'd go dual port. They didn't have those available back then. Worked for me. I'm pooping at home. 💩
From racing a friend with a WRX and a BOV at the quarter mile, I can literally see him pause while I pull during every shifts because there was no recirculated air going back to help the turbo get out of vacuum quick as the BPV. Every point was good, just don't do it!
This actually helped me a TON. Since buying my car it has not had the recirc hose and it has never idled right. Heading out to a place tomorrow to pick one up and see how it runs! Appreciate you!
The cars not going to be driven for a month and will be returned before driven but not a bad idea, also can let the ECU relearn by driving normally for a bit
Smeedia yeah 15 minutes is about what it needs to relearn. Your setup was def not happy with the hks bov I’m surprised it affected idle, wouldn’t it be closed at idle I tried to run a GFB fully adjustable bov but it works differently to Evo x oem bov (not sure how) Even though spring pressure and venting is adjustable I didn’t like how it felt or sounded GFB can be set to fully recirc, but still to different to what car is expecting Definitely need to tune for these Aftermarket bovs Check this out, th-cam.com/video/bsy9hJic7cQ/w-d-xo.html
It was odd, if only effected idle under load, if I was strongly and not moving it did not change anything. The cars getting torn apart tomorrow until the pro tune, if I was driving it again soon then I would go through the relearning process. Car def did not enjoy that 😅
Hello again! Thanks for the information in this video. I finally got my COBB titanium exhaust with j pipe, intake, and access port for my 2019 STi. Super excited to install this weekend. Thanks for all your videos. Next will be AOS... crazy install for that.
I was told that having the j pipe I might need to add a boost control. Said sometimes with the j pipe the boost in 3 and 4th pulls can be too much. So might have to get that installed as well.
Another great video you could do is a very detailed video on how to properly jack up your 2015-2020 Subaru STi. Show all jacking points and where to place jack stands. No one really has a good video for this and some are too short. Just an idea.
your short trim/ long trim numbers will go crazy. When I had mine vent to atmosphere. When I let off the gas, it does -25 percent for like 1-2 seconds. Btw keep up the good content.
I have a 2015 wrx and have been running a bov for about 4 months never had an issue that I felt the car was in danger and overall it has ran better than it did before.
Thanks for clarification! This is my first Subie, and I have often wondered what would happen if you put a blow off valve on a stock car. As soon as you turned the ignition on I could tell she wasn’t happy at all lol. Thanks for everything you do for the channel!
After the rich cycle you get a lean cycle that follows which is thr main drtrement to the engine, but a tuner can mitigate that to a degree during a protune
On my 04 wrx with an ej20 I had an hks bov and the car ran fine up til 170,000 miles and the only reason the car died was because it was crashed and totalled. Never had to replace a cat and the car never left me stranded once and I had no idle problems. I did have a turboback exhaust, intake and a ots ecu flash tune. Now with my 2022 wrx I don't need to do it for the sound because the stock bpv makes a lot of whistles and whooshes and some nice turbo flutter by just replacing the intake.
See great information about everything. I'm new to the channel and I'm really impressed with the knowledge but I'm impressed about everyone in the Subaru community doing these videos on our beautiful platform. Keep up the good work brother. Stay safe and have a good week.
The only reason the car is stalling out on you is because you’re venting to atmosphere instead of back into the system that you’re tuned for. You could get a tial qr which is a recirc bov and it’ll be just fine.
I'm aware, I knew the car wouldn't like the BOV and the point was to show that the car is not happy with it, generally most OTS and OE tuned cars will act the same so was trying to demonstrate what actually happens rather than just talking about it
I ran a BOV on a stock STI 2018 and had 0 issues. Currently I’m no longer stock and have a Stage 1 OTS tune and it shows no issues I’m not rich or lean, just yesterday I got a -1.40 knock and -1.40 knock learn
I love the sound that my go fast bits bypass valve makes. I never felt the need to do a blow off valve. My suggestion to anybody that wants cool turbo noises is to install a intake and get it protuned. The stock air box muffles all the noise the of the turbo and the stock tune is pretty bad on these cars anyway.
The Ecu does take a little minute to calibrate it...... If you have the accurate back pressure it should be OK. Does make some good or bad depending on you. At super high revs. That's a good thing to monitor. But... Put anything on it.... Go get it tuned. I'm not smart enough but there's always a dude that is 😅 love the vids man.
So I'm new to cars period. I just ordered a 2021 WRX Limited and I want to learn all the things. I took a quick course they offered on post to learn basic engines, watch some videos to learn about the turbo, boxer, direct injection, etc. My understanding of all this is very very basic. If I'm watching this saying, math based car? Speed density? Blow off valve? Charge piping? Where can I start to learn about all these things? I got a little overwhelmed when I tried starting with nasoic. Long road ahead but I want to know. BTW I'm a nurse so I'm literally starting from the ground up. Thanks!!
Makes no sense. If you had true in depth knowledge on this you would know that installing the bov wouldn’t change the idle of the car one bit. The only time the blow off valve will effect the air fuel ratio of the car is when there is pressure built up in the manifold and then the throttle is closed (during shifts) although I don’t run a bov on my car because I prefer the performance gains of a bypass valve(keeping more air in the engine during shifts) they will not hurt the car. As you said they will make it run more rich during shifts which may foul spark plugs faster but really won’t make a huge difference. On top of that Subaru’s use open loop fueling once in higher loads even when you are pro tuned with a cobb. Open loop fueling uses a target air fuel ratio or lambda and can very slightly adjust injector duty cycle to change your air fuel ratio and get it back to normal. Also you mentioned that the car showed some amount of fine knock learn when you were leaving the driveway which cannot be due to the bov. Fine knock learn is a ignition timing adjustment that the ecu makes over a long period of time when it tends to see knock at a particular load and rpm. If the bov was causing some sort of detonation, you would see that in feedback knock which is a real-time adjustment made by the ecu immediately when it senses detonation. Just thought I’d give you my .02 since I have built a few of these engines and tuned a couple
My dream is to do no bpv or bov on a speed density tune just for the turbo flutter and slight weight savings lol. I agree on not using one on maf, but at least you'll shoot some flames!
@@Smeedia Tell me about it. If I had a dollar for the number of times I had to drive 10min+ out of the way to go around a stopped train I could put new Garrett Turbos on both my 95M and 96 Miatas and not the GT2554R and GT2560R I have now. lol
Just replaced my FP blue with a dom 2.5 xtr, similar but seems to spool louder and "hit" a little bit harder. Only replaced because mine had a hairline crack that made the car smell like burnt oil. The FP blue looked and felt like a stock turbo which is why I liked it.
the "bypass" valve is a BOV that is recirculated, its not a "bypass valve" its just a BOV that's been designed to recirculate the air back into the system there are also BOV's designed to do both at the same time like the Turbosmart BOV's .. in Australia its illegal to run a BOV Vent to atmosphere..
I bought my 12’ STi with a BOV already installed (and intake and exhaust) and a protune. Seems to run great, anything else I should look out for or be worried about? Knock monitoring is all within normal limits. I’m straight ricer and dig the noises. If it’s okay, I think I’ll keep it. Will have tuner check out car just to be safe. What do you think? It’s just tough cuz there’s so much polarity in this topic… hard to get a straight answer
... Unless you're in boost and let off, there is no "metered air" for the maf to see. So you're idling and revving would not tell you anything about the blow off valve because it's not even in use. And it's not running rich from that. The car won't add fuel because there's not extra air. So, with a recirculating valve, the car adds fuel for the extra air, when the blow off vents to atmosphere there is no extra air so no extra fuel needed. Thats the whole purpose in the maf... Also, if your car is running rich (as long as you have a proper tune with proper timing) the only damage that can be done is shortening the life span of your spark plugs slightly. Also just want to point out "I don't want to drive and risk hurting the engine" *proceeds to cold rev the shit out of it* Almost everyone I know runs a BOV and none of us have had an issue.
Go watch GFBs video on BOVs. Sure it's not how the manufacturers intended it to be but you're not going to blow up the car solely because of a blow off valve. You're more likely to blow up your Subaru by oil starvation or head gasket problems. That dip in the RPM was just the ECU learning how to cope with the BOV. There's plenty of people running BOVs without even an e-tune.
Head gasket issues were only problematic on early 2.5 N/A motors. Any OTS or stock tune is going to struggle with a BKV on a car that is full recirc and MAF based. The ECU has no idea what is happening to the lost air. Any vendor or manufacturer is going to say no tune needed because it increases sales #s
the car is going to run rich only after the blow off valve opens not on idle or cruising XD unless the spring is set extremely soft edit: hybrid is best of both world imo
The issue with the BOV is when the car is not produced with it and is paired with a OTS Map or OE tune. As long as the tuner is fine with it and tunes the car with it, the WCU has some idea of what is going on
@@Smeedia I agree letting metered air escape is no good, but a 50/50 bov will not make a car run much worse, just richer as you shift. The stalling and stumbling happen on fully atmospheric bov like the Hks or set to a low spring pressure .
@@samuelaudet845 That's actually incorrect. 50/50 Hybrid valves will make the car behave exactly like this. You will have stalling issues, rich A/F mixture issues. I know this because I have a Turbosmart 50/50 hybrid valve, and ended up going back to stock BPV because I got tired of dealing with the stalling, richness and turbo flutter (because of the FMIC).
Made it to the tuner today! Hopefully I'll get it back this week 😬😬😬 Its been down for 2 months, it was so nice driving it again... even though I had to take it super easy Iol
Still baffles me why Americans refer them as blow of valves and by pass valves.... makes so much more sense to state it as vent to atmosphere or recirculating bovs No explanation needed once you state them that way!
Update: Don’t do it boys. I’m getting a check engine light now from the BOV, as when I have it open the light is on and when it’s closed it turns off. Selling this B.
Good god that train. 😂 You have been educating me sooo much about Subarus. Gonna lease one soon. At least i know what to do and not do. I feel like more people who are into BOV need to know this or those who are going from a BPV to BOV. To each its own right? Great content.
Exactly, people are totally free to so as the please with their mods, but agreed I at least want people to be aware of the potential issues of using one. And glad the videos are helping my friend!
Hey bro i just got a ‘19 wrx and in a nutshell ..... don’t run a blow off valve stock ? And you said if you do , to get a tune? But I thought the Cobb AP was for that ? And if I don’t get a blow off valve what can I run that’s healthier for the motor? Is the hybrid valve better ? Sorry for buggin, I came from a static 96’ LS400 so I’m in a whole new world now with a Subaru lol
Your at least tuned for it, the real issue is stock cars at ones using OTS maps that install it. OTS maps already have their own set of issues but pairing a BOV with an OTS Map and OE map its bound to not have a good time 😅
@@brannonatkinson the issue is the bov is staying open when your hitting the limp rpm mode. You have to adjust the bov so it doesn't open easy and closes before you hit limp rpm mode. Gfb dvx has this option.
If tuned accordingly is the bov still worth it? Or is it better just having the bpv overall even if tuned properly? I want the sounds but definitely wanna keep the engine as reliable as I can
@@jacksonr1337 I’ve had a gfb respons on my ej20 for ages with no issue, 30/70 atmospheric and recirc with a few adjustments to the valve spring tension to get it perfect and it runs like stock plus the cool noises
@@nes3382 in the exact same boat here. i love the GFB and have it set up the same way as you. Its definitely worth it to get an adjustable BOV like GFB or turbosmart!
So what you’re saying is before I buy an aftermarket BOV, I should do my full exhaust, tune and involve the bov all in one no? I’m bome stock. Just trying to add some pep. Try working for the railroad … trains give me nightmares lol
I had my wrx tuned by my tuner with the gfb response bov it was tuned with it open to atmo before tune ran so bad but I agree it does cause knock and idled so bad now it runs perfect now after tune
I get that it's an MAF based engine. I have a stock tuned STI that I recently picked up with a 50/50 valve and an ETS front mount and an intake. Knowing how anal everyone is they are probably gonna die just reading that sentence. Yes I do plan on tuning it. The ONLY thing I've noticed vs driving my friends pro tuned car with a fully recirculating valve is that once I get near atmospheric pressure (0, no vacuum or boost) the car does tend to kinda stumble a little. Though I'm guessing that's more of the fault of the intercooler. The car has never smelled rich, even with a muffler delete on it. Never stumbles at idle, no dips at idle, nothing. These valves ONLY open once you reach boost. Sure you went into launch control, but boost is pretty low on that. Not only that, there was no apples to apples comparison here. What were the numbers before the BOV? The title is also "don't do this to your STOCK Subaru" my guy, your car is pro tuned and is far from stock. I don't see how your trying to make an argument when there are other people who aren't experiencing these issues, or if you have or have not experienced them yourself and if this is all just speculation. Also modern cars knock, ALL the time. The knock sensor is there to help find out if it needs to lean or rich the system to prevent it. The cars ecu makes the adjustments necessary. I'd bet that if you would let the ECU learn more, it would run better, instead of letting it idle for 5 mins, doing revs / launch control, going back and forward 2 or 3 times, and then saying "yep, BOV bad, only do recirc valves"
Watched your vids... Amazing... Got a 2019 wrx stock, i did put the gfb bov and have it at full recurc. I feel the car jerky at times. Should i go back to stock bpv or upgrade to aftermarket bpv and take the loss. 😬
I am brand new to the gas car society, got a 2017 STI and I love the sound of your exhaust. First question, what kind of exhaust and what do I need to run that exhaust like a tuner? I had to have a tuner on my diesel to run a straight pipe. Second question, what do need to do to the engine to install a BPV or BOV. Thank you so much.
The exhaust was a Cobb catted downpipe and an ETS Extreme catback, all you need to run those is an accessport. You can install a BPV without needed to tune but a BOV will require at minimum a protune 🙏
This is a common myth. The system is dependent on 1) the TPS signal, and 2) the BOV itself.
Modern fuel injection system do a fuel-cut on decel to 1) save gas, and 2) alow the revs to drop faster; the fuel-cut decel should override any fuel delivery (issues).
If the TPS is slightly off, it'll keep shooting fuel on decel - this is how you get the popping on decel or in between shift.
If the BOV doesn't seal fully (which it sounds like this is the case in this video), you get an intake vacuum leak - what were the vacuum #'s before and after the BOV install? Was it the same?
I've seen plenty of BOV's that leak on WRX's / STI's...
Making a BOV that 100% seals at idle makes it more expensive to produce.
If the BOV is sealed 100%, the system is closed, and your idle should be identical to before - the fact that you're running rich means something else has changed.
This is why some people have no issues, and why some people do have issues.
Jesus christ ur good
You are 100% right a bov shouldnt affect idle unless its leaking
I was gonna say I bought my 19 wrx used that came with an HKS BOV and it’s closed system, i didn’t think it had a MAP for it installed already but I don’t have any idle issues what so ever since purchase. Seems to be working A OK. Still need to get an AP for her but other than that no issues still 🤞🏻🤞🏻
I'm not that sure.
I have a Suzuki Swift Sport ZC33S (from 2018), and I installed recently (a month) the HKS SQV IV valve and I'm experiencing some of the symptoms that he says.
Today I'll mount the recirculating tube, to see if that mitigates the lagginess and stuttering in very low revs, like when I'm in the middle of heavy traffic.
Saddily I'll lose the high pitch sound, but in the long run I prefer to not to damage the engine.
Or they don't block the recirc hose that goes to the intake after MAF
Hey man, there is no way that it would make a difference running that low RPM, The BOV only opens up to let the air out when the boost pressure is above 0 (Hence the BOV sound). Anything below 0, you should not even notice the difference because it's a closed system... So with all do respect, what you are saying does not make sense. If its open below 0, that would indicate a boost leak.
especially when running something like the GFB TMS Hybrid. Zero chance you’re gonna mess up the closed loop system if you’re setting the spring tension correctly. That’s literally it.
Good reply, the poster never replied to this because you mention facts.
Let me know when you start making videos so I can follow you instead. Your comment is common sense, literally entering the chat.
@@panderalexander exactly
I blew up my 2011 wrx because i added a bov on my cobb OTS map. ran lean and threw a rod
Jokes on you I don’t have cats
Read this as I was thinking it🤣🤣🤣🤣🤣
What do you mean is a bov better for catless
What do you mean are the bov better for catless
Same lol
Same
Idk man, I know science is science but I’ve owned 3 Subaru’s, rocked a BOV and OTS tune on all 3, put easily 75k+ miles on all 3, and had 0 issues related to the BOV. All cars were tested and healthy at time of sale. Maybe I’m just the lucky statistic 3 times over. Nice video and very informative though, keep up the good work
Justin Geier same loool
I've seen some cars respond different using OTS Tunes, if you have a higher quality valve it would mitigate out some of the leaking issues that other valves have had.
Right. I just installed a fully atmospheric bov on my 2018 sti and I didnt have an of these issues that smeedia has. Maybe theres some underlying issue causing the knock in this video? I installed mine after watching and did little revs like this and not a single issue. Maybe its cause his bov spring was too loose and was by passing even the slightest bit of pressure? Maybe it's not having that long pipe on the ic piping for the stock bpv location? But I dont think that knock issue is directly because of installing a vented vs recirc valve.
@@enemen8 The car is not designed for it, doesn't mean you can't get away with it. Typically the Supreme crowd or "younger" crowd throw them on without knowing anything, go get a tune and ask for the "Can i get a dope crackle n pop tune with a touch of flames out the exhaust, bruh?"
@@enemen8 no matter what it's not good for the car
Now that you mentioned it, you gotta make a video explaining speed density
Thats difficult, ill see what I can do to make it easily understandable 🔥
MAF measures the mass of air that enters the engine. Speed density calculates the amount of air that goes in the engine by measuring pressure, manifold air temp and rpm. You must use a float valve style BOV that does not stay open under vacuum. If so you simply need to change one number in the tune. His engine is actualy over correcting for running lean because its sucking in air at the BOV.
I did a ton of reading about speed density vs maf tuning for my lt1 corvette motor. Same concept different platform. I’ll see if I can find the link, it’s a ton of relevant information to the topic
See, its a missconception. You can use a twin piston/diaphragm type atmospheric bov on maf setups and they work as perfect as they do with the recirc valve.
If you were car guys youd know this...
Ive run a loud bov on every turbo car ive had and all being maf setup.
Do some research and stop talking shit.
@@Smeedia What about a HKS Super SQV4 Blow Off Valve would still need a full speed density tune?
Been running my bov for 18 months on 380 HP wrx. No issues at all.. I stay up on maintenance, and plugs look normal. I recommend getting one if you want.
Did you get produced with it on the car? The major issue of it is using a BOV on a Stock car or one with an OTS Map which already have their own issues with them.
@@Smeedia it was the first mod I put on my car and I ran it for over a year before getting a protune.
I have an fully recirculating hks bov paired with a cobb big sf intake. E-tuned by William Knose at Delicious Tuning by the way. In my opinion, this is the way to go if you want those spooly boy noises. The stock airbox muffles alot, so you can certainly hear the bov noises through an upgraded intake. Side note, my hks bov is a 13 year old original version from 2007, that was still brand new in the box that I never used for a prelude build I never finished before joining the Marines.
Thats a good find to be able to reuse! And the intake really helps to bring out a lot of those noises as you said 🔥
@@Smeedia Is the BOV different when the car has MAP rather then a MAF? 2018 Hyundai Elantra Sport to be exact. thanks
@@perziano6134MAP and MAF are not interchangeable unfortunately
I just installed the AEM chargepipe today and realized at the end that those suckers didn't include the recirculation hoses as the AEM relocates the BPV on top of the engine...same situation...car runs way rich with CEL P0170, car stalls when coming to a stop...smell of rotten eggs...waiting on delivery of the hose...thank for the video this clears things up...i swear you da best! And the only youtuber I came across that responds the same day lol....Bless you bro
Hopefully you get it taken care of my man! Small problems will always be the issue 😖
I like how he "smelt fuel" when afrs were stoich
"I'm scared because the rpms are dropping low" probably because the ecu is trying to re learn everything. What exhaust is that? Kinda sounds like dookie
Also you said that the extra fuel would get into your oil as it ran down the cylinder wall. You would have to be running insanely rich to have left over liquid fuel in your combustion’s chamber(like 5:1 gasoline). Also your wideband afr gauge on the right side of your steering wheel was reading anywhere from 14.5-15.1. Not rich at all as the stoichiometric air fuel ratio of gasoline is 14.7:1
Id guess you done have it setup right. My GFB Hybrid BoV was installed by a master tech at a Subaru dealership and I have 0 problems. Its running about 50/50 recirc/vta. Also its only going to "run rich" for a split second during a high rpm shift. If anything that split second of rich is going to help vs engine knock.
Its been on the car for 2 years (35k+ miles).
how much you pay for it?
I have the same BOV on my 2015 STI Works amazing with a higher hp setup too. No dedicated tuning but I will be tuning this winter
@@jeprodigalson792 Im at 72k miles now everythings still great. Still no tune.
I just bought a side project car and its a used 2013 WRX STI Sedan Sporttech usualy they go for around 17K + I got it for 10K 1.has very small body work to do (only minor rust spots) 2. needs a new paint job 3. The car runs but dosn't run well. Coming from the dealer that I bought it from every time I hit the stop sign or light that choking issue 9:01 happened. I stalled at 3 stop signs.... Got home opened up the hood and the air circlation hose is cut and plugged... stock BOV... So I got on to watch videos on Bypass valves and blow out valves and I want to say thank you! Easy fix just need to get another hose!
Thanks for the info @Smeedia
Hey Tanna, it's UK Subie guy. Waw, it's been a long time from this video, & You buying my dream car for the next chapter of the channel. I really like seeing the influence you give out in every video, no matter how hard the next part instal/removal. There are so many Great car covered ytube channels adopting your style & weeding out the fake weekend mechanic. Gracias mi amigo 🇬🇧🤘🤘🤘🤘
Always appreciate the support my friend ❤️
This made me proud of choosing the Perrin Bypass :)
Perrin is a good option to use! 🔥😁
@@Smeedia Excuse me but what's the purpose of replacing a bypass with another bypass?
Spring pressure, the OEM valve can hold around 20lbs of boost but once you start to exceed it you need a stronger valve
@@Smeedia So it's a must in highly modified turbo engines?
Yessir 🙏
Yo! Thank you bro! I am new to owning a wrx sti (2021) and I have relied on you to learn more! This is fantastic for people like me learning!
Glad I can help! Congrats on the car as well!
@@Smeedia Thanks man appreciate it!!
If you setup BOV correctly the car will not idle or run ANY different, unless you did it wrong then it will idle differently, or its a POS like that valve,
If you can smell fuel or it runs different you done screwed up and not installed it correctly or its not adjusted correctly,
during idle the valve is 100% closed and doing nothing so wont effect anything.
(High quality valves like GFB Hybrid are the best and cant even leak even if 100psi boost)
Makes almost no difference it only runs lean for 0.15 - 0.3 seconds when you let off the gas and as you are not making power it does not matter if AFR's goto full rich
If coasting down a hill in gear AFRs are meaningless as injectors are shutoff during coasting.
Even the guy who started the rumor in the UK admitted to it after like 15 years that he was just making it up as he hates all the ricer Subarus going around making blow off noises (Ricer/Racer boys)
It all started from him and was just a joke,
Just like the DR who joked about Vaccines causing Autism in a paper he wrote and accidentally started the now stupid idea people have that its real, Even year later when he said it was just a joke in the paper he wrote people wont believe him and say he must have been paid out by Big pharma.
Put it on dyno and watch the lean condition is so short if you blink you WILL miss it as human eye takes .25 seconds to blink so easy to miss a rich condition that last .15-.3 seconds.
If you are serious about tuning should be replacing the plugs every 10,000KM as they will be copper spark plugs which are best for fuel burn and so on.
Big ups to Tanner for willing to use his car as a guinea pig to show what not to do. Alot of people still dont understand a stock MAF setup vs a MAP setup.
Figured the best way to present the information was to just show it to everyone, if I can help save some engines I would like to do so 🙌
The BOV isn't what was causing your issues at idle. How could it when there is no boost to blow off?
Regardless, you can't tune for a BOV. I get really tired of telling people that. There is no special table for "WOT release" or anything. They do slightly increase how rich the car runs for that brief moment when letting off the throttle, more pops and bangs, which in turn can hurt the cat and turbo since those explosions are happening nearby.
With Speed Density, there is no tuning you can do either. It's just that the reference of MAP is a lot closer to the injectors than the MAF is, so there is a lot less time of fuel squirt at WOT release.
Anyway, I am so sick of BOV arguments, and this video makes it worse. 175k views and counting ;(
@@sssnake2332 Thanks for the explanation! I bought my '18 STI a little over a month ago which came with a GFB bov, and I've been reading forums on the subject ever since. I don't have any of the issues that Smeedia was having in the video so I wasn't too sure what to think. I love the sounds my bov makes, but I'm not going to keep it on at the expense of my cars health... :C
RIP 😢
This video makes me laugh lol “the car smells rich “ I installed a hks bov on my sti and had no problems honestly it’s running great,
Talk to your tuner.
As long as your not on an OTS Tune with the BOV its not a huge issue. A protune fixes a lot of the out the box issues associated with just slapping one on
Smeedia I believe I’m on a OTS tune at the moment, I have to talk to my tuner but it’s so weird that your car has symptoms like that. Have you had any updates on it?
I pulled the BOV off the car after the vidro and stayed with the bypass valve, im going on a hybrid speed density tune so because I am still utilizing some of the MAF I'm sticking with thr BPV. But based off of what I did im sure the BOV was leaking air causing idel to be all screwed
Smeedia I would like to come help you maybe the rubber inside the inserts were not tighten down? Or the rubber seal bad? Also my kit came with a recirculating kit with my hks bov, if you want you can try it on your car if you wanna run the hks!
I only used the BOV as an instructional piece for the video to demonstrate the effects of an out the box BOV on an OTS TUNE. But greatly appreciate the advice!
Great Video! A few years ago I purchased a RFL blow off valve, had it installed with the idea it was a plug and play, I was so wrong. No matter how many washers, ( how it said to adjust ) caused the car to stall at every stop, and turn the tail of my car black from running too rich. To make a long story short, it’s back in the box and sitting in my trunk. I wish I saw your video 3 years ago!
Glad that you got it sorted out, and some cars react different than others from what I've seen most think that BKVs are plug and play but so much more to them than one thinks. Appreciate the added sorry and kind words!
I should’ve watched this video before I almost messed up my engine..got a 2004 wrx and installed this bov the whistle so freakin nice but after few months the sounds started to go down until its gone and after that i startedto hear like fluttering noise from my engine and dont know wth is going on even my mechanic got headache i gave him tylenol..please listen to this guy and dont install that piece of crap.🤓
🙏🙏🙏🙏🙏
This was a good laugh. I ran a vent to atmosphere bov on a decently modded, not built 7 bolt 22psi 2g awd dsm from 60k-280k miles. To counter this, I ran a k&n style breather after the maf. My af gauge read super rich before the breather. Came back down to not so rich and good levels after. If I did it again, I'd go dual port. They didn't have those available back then. Worked for me. I'm pooping at home. 💩
From racing a friend with a WRX and a BOV at the quarter mile, I can literally see him pause while I pull during every shifts because there was no recirculated air going back to help the turbo get out of vacuum quick as the BPV. Every point was good, just don't do it!
Taking that turbo a little longer to get that air moving again, appreciate the support and feedback!
This actually helped me a TON. Since buying my car it has not had the recirc hose and it has never idled right. Heading out to a place tomorrow to pick one up and see how it runs! Appreciate you!
Should help with the idea issue a lot 😁 glad the video helped!
Great video! These videos are keeping me from ripping my hair out during this quarantine
Glad that they're helping my friend!
What are your thoughts on the HKS blow off valve with the recirculating kit to make it a bypass valve?
I recommend using your AP to reset ECU learned values before/ after swapping bovs
The cars not going to be driven for a month and will be returned before driven but not a bad idea, also can let the ECU relearn by driving normally for a bit
Smeedia yeah 15 minutes is about what it needs to relearn.
Your setup was def not happy with the hks bov
I’m surprised it affected idle, wouldn’t it be closed at idle
I tried to run a GFB fully adjustable bov but it works differently to Evo x oem bov (not sure how)
Even though spring pressure and venting is adjustable I didn’t like how it felt or sounded
GFB can be set to fully recirc, but still to different to what car is expecting
Definitely need to tune for these Aftermarket bovs
Check this out, th-cam.com/video/bsy9hJic7cQ/w-d-xo.html
It was odd, if only effected idle under load, if I was strongly and not moving it did not change anything. The cars getting torn apart tomorrow until the pro tune, if I was driving it again soon then I would go through the relearning process. Car def did not enjoy that 😅
Hello again! Thanks for the information in this video. I finally got my COBB titanium exhaust with j pipe, intake, and access port for my 2019 STi. Super excited to install this weekend. Thanks for all your videos. Next will be AOS... crazy install for that.
Promise the AOS is not as bad as people make it out to be
I was told that having the j pipe I might need to add a boost control. Said sometimes with the j pipe the boost in 3 and 4th pulls can be too much. So might have to get that installed as well.
Another great video you could do is a very detailed video on how to properly jack up your 2015-2020 Subaru STi. Show all jacking points and where to place jack stands. No one really has a good video for this and some are too short. Just an idea.
Yes I can add that into or make a video on it 😁
your short trim/ long trim numbers will go crazy. When I had mine vent to atmosphere. When I let off the gas, it does -25 percent for like 1-2 seconds. Btw keep up the good content.
Appreciate the added input! Appreciate the support and much more to come 🔥
I have a 2015 wrx and have been running a bov for about 4 months never had an issue that I felt the car was in danger and overall it has ran better than it did before.
Thanks for clarification! This is my first Subie, and I have often wondered what would happen if you put a blow off valve on a stock car. As soon as you turned the ignition on I could tell she wasn’t happy at all lol. Thanks for everything you do for the channel!
Honestly atmospheric dump valves don’t really harm the car at all, it only causes it to run rich for the second or less you let off and it dumps air.
After the rich cycle you get a lean cycle that follows which is thr main drtrement to the engine, but a tuner can mitigate that to a degree during a protune
On my 04 wrx with an ej20 I had an hks bov and the car ran fine up til 170,000 miles and the only reason the car died was because it was crashed and totalled. Never had to replace a cat and the car never left me stranded once and I had no idle problems. I did have a turboback exhaust, intake and a ots ecu flash tune.
Now with my 2022 wrx I don't need to do it for the sound because the stock bpv makes a lot of whistles and whooshes and some nice turbo flutter by just replacing the intake.
See great information about everything. I'm new to the channel and I'm really impressed with the knowledge but I'm impressed about everyone in the Subaru community doing these videos on our beautiful platform. Keep up the good work brother. Stay safe and have a good week.
Dont use full vent to atmosphere like hks or greddy use a gfb or turbosmart adjustable bov.
I have a gfb hybrid set at 50/50 and I’ve had no drive ability issues. Even drove 16 hours on it last week
I have a turbo smart adjustable bov set at 50/50 at 150,000kms no issues at all.. (2015 sti)
I have the gfb respons bov and had the car pro tuned and it’s perfect on my 2015 wrx
@Mintieness is the gfb hybrid safe if your car is not tuned or don't have accessport??
SuperTech Idol that’s what I’m using with still no issues. No tune, still have my warranty
Is your sti stock? or tuned?
The only reason the car is stalling out on you is because you’re venting to atmosphere instead of back into the system that you’re tuned for. You could get a tial qr which is a recirc bov and it’ll be just fine.
I'm aware, I knew the car wouldn't like the BOV and the point was to show that the car is not happy with it, generally most OTS and OE tuned cars will act the same so was trying to demonstrate what actually happens rather than just talking about it
I ran a BOV on a stock STI 2018 and had 0 issues. Currently I’m no longer stock and have a Stage 1 OTS tune and it shows no issues I’m not rich or lean, just yesterday I got a -1.40 knock and -1.40 knock learn
I love the sound that my go fast bits bypass valve makes. I never felt the need to do a blow off valve. My suggestion to anybody that wants cool turbo noises is to install a intake and get it protuned. The stock air box muffles all the noise the of the turbo and the stock tune is pretty bad on these cars anyway.
This^
Damn right! My Cobb short ram has all the wooooosh!
Well done sir. Hope a lot of newbies see this video.
Trying to save people from putting a BOV on a car with a OTS or OE tune. Hopefully it helps some 🙏
@@Smeedia this is a daily question I get from customers. I'm happy someone made a modern video explaining it. Well done.
Fr I was going to install a BOV that I got from a friend for my wrx 15 with a OTS tune but after this ima return it to him 😞
I have a stock 2010 STI with an hks bov and my car drives perfect.
As long as it is working for ya 🔥
The Ecu does take a little minute to calibrate it...... If you have the accurate back pressure it should be OK. Does make some good or bad depending on you. At super high revs. That's a good thing to monitor. But... Put anything on it.... Go get it tuned. I'm not smart enough but there's always a dude that is 😅 love the vids man.
Great video. Nice info in there. Can't wait for the disassembly.
Same, so many parts will be everywhere 😅
@@Smeedia at least you have a nice shelving unit to 'organize' them. Hopefully it will be controlled chaos.
It will be some type of chaos alright 😅
just installed my hks on my stock wrx today. Keep the videos coming bro
Just make sure to monitor fuel trims and set slring pressure on the BOV to help prevent it from leaking!
So I'm new to cars period. I just ordered a 2021 WRX Limited and I want to learn all the things. I took a quick course they offered on post to learn basic engines, watch some videos to learn about the turbo, boxer, direct injection, etc. My understanding of all this is very very basic. If I'm watching this saying, math based car? Speed density? Blow off valve? Charge piping? Where can I start to learn about all these things? I got a little overwhelmed when I tried starting with nasoic. Long road ahead but I want to know. BTW I'm a nurse so I'm literally starting from the ground up. Thanks!!
Thanks for this vid, was looking at a super nice 04 wrx wagon with 0 rust but it's running a BOV and OTS tune so I guess I'm skipping that buy.
Makes no sense. If you had true in depth knowledge on this you would know that installing the bov wouldn’t change the idle of the car one bit. The only time the blow off valve will effect the air fuel ratio of the car is when there is pressure built up in the manifold and then the throttle is closed (during shifts) although I don’t run a bov on my car because I prefer the performance gains of a bypass valve(keeping more air in the engine during shifts) they will not hurt the car. As you said they will make it run more rich during shifts which may foul spark plugs faster but really won’t make a huge difference. On top of that Subaru’s use open loop fueling once in higher loads even when you are pro tuned with a cobb. Open loop fueling uses a target air fuel ratio or lambda and can very slightly adjust injector duty cycle to change your air fuel ratio and get it back to normal. Also you mentioned that the car showed some amount of fine knock learn when you were leaving the driveway which cannot be due to the bov. Fine knock learn is a ignition timing adjustment that the ecu makes over a long period of time when it tends to see knock at a particular load and rpm. If the bov was causing some sort of detonation, you would see that in feedback knock which is a real-time adjustment made by the ecu immediately when it senses detonation. Just thought I’d give you my .02 since I have built a few of these engines and tuned a couple
My dream is to do no bpv or bov on a speed density tune just for the turbo flutter and slight weight savings lol. I agree on not using one on maf, but at least you'll shoot some flames!
Holdenian everybody wants flames lol
My old skyline was like that and the car ran awful, was not set up for it though 😅
3:10 I hear that you too have to deal with Trains and their lovely horns. lol
Lol they're just a blast to live by 😅
@@Smeedia Tell me about it. If I had a dollar for the number of times I had to drive 10min+ out of the way to go around a stopped train I could put new Garrett Turbos on both my 95M and 96 Miatas and not the GT2554R and GT2560R I have now. lol
I’ve been running about 8 months strong on a BOV on a stage 2 OTS tune 💀 one day I’ll get tuned.
I run twin piston atmospheric collins bov on my maf setup car as i have with all my maf setups without throwing an engine light.
waiting for that fp blue install video !!! i have mines in the box waiting to be installed :) awesome channel keep up the great content tanner!
Jealous I'm impatient and want to have mine 😅 should have it in a few days. Appreciate the support and feedback!
Just replaced my FP blue with a dom 2.5 xtr, similar but seems to spool louder and "hit" a little bit harder. Only replaced because mine had a hairline crack that made the car smell like burnt oil. The FP blue looked and felt like a stock turbo which is why I liked it.
Excited to get mine, it will be. A kce bump over the VF48, I was eye balling the 2.5 XTR for a while
@Smeedia thanks this was really helpful!
I put one on mine 2 years go, no tube, it literally cost me £30 and it’s absolutely fine.
Haven’t read all of the comments but dibs on that Cobb BPV! 👀
Lol actually going to end up using the BPV Still, because I'm using. A hybrid SD Tune ill still be using a BPV with the car 😅
Smeedia Will you get Tuned for the BOV in the future?
When we go full speed density yes
glad i saw this video i was going to buy a hks for my hatchback . think i will leave it standard.
I have a GFB bov but I believe it set up to recycle back like a bypass valve and it has the tube. It was on the sti before I bought it
I have a stock 2016 sti with aps bov its all good nothing to worry. Even my tuner told me its ok but depend how you drive
Thanks for the video because I was about to buy it… Whig kind of dumbvalve I should buy for a stock WRX 2006? Thank you man 👍🏻👍🏻👍🏻
Nice video bro
What if I'm running both SD and MAF running BOV should be good with pro tune? 400whp
Gave the video a thumbs up before it started because I KNEW it was gonna be good!
Eyyyy, appreciate the support 🔥🙌😁
I don’t even rev my stock Sti to 5k so I hope I baby mine forever and keep it mint
the "bypass" valve is a BOV that is recirculated, its not a "bypass valve" its just a BOV that's been designed to recirculate the air back into the system there are also BOV's designed to do both at the same time like the Turbosmart BOV's .. in Australia its illegal to run a BOV Vent to atmosphere..
th-cam.com/video/bsy9hJic7cQ/w-d-xo.html
I bought my 12’ STi with a BOV already installed (and intake and exhaust) and a protune. Seems to run great, anything else I should look out for or be worried about? Knock monitoring is all within normal limits. I’m straight ricer and dig the noises. If it’s okay, I think I’ll keep it. Will have tuner check out car just to be safe. What do you think? It’s just tough cuz there’s so much polarity in this topic… hard to get a straight answer
If it’s running great than fuck this guy 😂 listen to your car don’t listen to this twit spreading misinformation lmao
...
Unless you're in boost and let off, there is no "metered air" for the maf to see. So you're idling and revving would not tell you anything about the blow off valve because it's not even in use. And it's not running rich from that. The car won't add fuel because there's not extra air. So, with a recirculating valve, the car adds fuel for the extra air, when the blow off vents to atmosphere there is no extra air so no extra fuel needed. Thats the whole purpose in the maf... Also, if your car is running rich (as long as you have a proper tune with proper timing) the only damage that can be done is shortening the life span of your spark plugs slightly.
Also just want to point out "I don't want to drive and risk hurting the engine" *proceeds to cold rev the shit out of it*
Almost everyone I know runs a BOV and none of us have had an issue.
Go watch GFBs video on BOVs. Sure it's not how the manufacturers intended it to be but you're not going to blow up the car solely because of a blow off valve. You're more likely to blow up your Subaru by oil starvation or head gasket problems. That dip in the RPM was just the ECU learning how to cope with the BOV. There's plenty of people running BOVs without even an e-tune.
Head gasket issues were only problematic on early 2.5 N/A motors. Any OTS or stock tune is going to struggle with a BKV on a car that is full recirc and MAF based. The ECU has no idea what is happening to the lost air. Any vendor or manufacturer is going to say no tune needed because it increases sales #s
the car is going to run rich only after the blow off valve opens not on idle or cruising XD unless the spring is set extremely soft
edit: hybrid is best of both world imo
The issue with the BOV is when the car is not produced with it and is paired with a OTS Map or OE tune. As long as the tuner is fine with it and tunes the car with it, the WCU has some idea of what is going on
@@Smeedia I agree letting metered air escape is no good, but a 50/50 bov will not make a car run much worse, just richer as you shift. The stalling and stumbling happen on fully atmospheric bov like the Hks or set to a low spring pressure .
@Smeedia I've been out of the tuning game 12+ years, but at one point HKS made a recirc adapter. Do they not anymore?
@@samuelaudet845 That's actually incorrect. 50/50 Hybrid valves will make the car behave exactly like this. You will have stalling issues, rich A/F mixture issues. I know this because I have a Turbosmart 50/50 hybrid valve, and ended up going back to stock BPV because I got tired of dealing with the stalling, richness and turbo flutter (because of the FMIC).
They still make the recirculating adaptor but its never utilized
Made it to the tuner today! Hopefully I'll get it back this week 😬😬😬
Its been down for 2 months, it was so nice driving it again... even though I had to take it super easy Iol
Mine will be down for a month before getting to drive it again 😫 hopefully all goes well with the tuner!
Whenever I google a question, you’re the first video. I appreciate all the help bro!
Glaf the videos are helping my man! 🙏😁
i do wonder is 50/50 bov will keep the richness in check?
Still baffles me why Americans refer them as blow of valves and by pass valves.... makes so much more sense to state it as vent to atmosphere or recirculating bovs
No explanation needed once you state them that way!
Should be a simple answer - 21' STI only with ETS Extreme, would an adjustable GFB BOV set to 50/50 on OE be okay? Enjoy ya vids, thanks. 👍
Of course you can with a speed density tune!
I run a GFB BOV open 50% on my stock 2015 STI. It has ran great for months
Your at least getting half of the air back into the system to help mitigate the issue
Smeedia thanks for the reply bro!! Made me feel a lot better. You had me scared there for a sec lol! Love all your videos! ❤️
Update: Don’t do it boys. I’m getting a check engine light now from the BOV, as when I have it open the light is on and when it’s closed it turns off. Selling this B.
And I’m still gonna do it✨
“I am worried to damage this car.” *free revvs and pegs redline*
Good god that train. 😂 You have been educating me sooo much about Subarus. Gonna lease one soon. At least i know what to do and not do. I feel like more people who are into BOV need to know this or those who are going from a BPV to BOV. To each its own right? Great content.
Exactly, people are totally free to so as the please with their mods, but agreed I at least want people to be aware of the potential issues of using one. And glad the videos are helping my friend!
Hey bro i just got a ‘19 wrx and in a nutshell ..... don’t run a blow off valve stock ? And you said if you do , to get a tune? But I thought the Cobb AP was for that ? And if I don’t get a blow off valve what can I run that’s healthier for the motor? Is the hybrid valve better ? Sorry for buggin, I came from a static 96’ LS400 so I’m in a whole new world now with a Subaru lol
Come for a subi video. Stayed for the train asmr
🤣🤣🤣🤣🤣
Been running HKS bov on my STI for 30k miles have had no problems but I did have it tuned when I installed that after
Your at least tuned for it, the real issue is stock cars at ones using OTS maps that install it. OTS maps already have their own set of issues but pairing a BOV with an OTS Map and OE map its bound to not have a good time 😅
Smeedia ya I remember I put it on without a tune it ran ok but some revving it bright the rpms down to almost stalling the motor it was bad
Thats what I was noticing as well, but it was only under load when it would try to stall out
@@brannonatkinson the issue is the bov is staying open when your hitting the limp rpm mode. You have to adjust the bov so it doesn't open easy and closes before you hit limp rpm mode. Gfb dvx has this option.
If tuned accordingly is the bov still worth it? Or is it better just having the bpv overall even if tuned properly? I want the sounds but definitely wanna keep the engine as reliable as I can
im in the same boat!!! I want the sounds!!
@@jacksonr1337 I’ve had a gfb respons on my ej20 for ages with no issue, 30/70 atmospheric and recirc with a few adjustments to the valve spring tension to get it perfect and it runs like stock plus the cool noises
@@nes3382 in the exact same boat here. i love the GFB and have it set up the same way as you. Its definitely worth it to get an adjustable BOV like GFB or turbosmart!
@@jukebox9175 100%
All you need is a pro tune.. I’m running an hks ssqv and I’m maf based. Making 393whp 430wtq.
Agreed, as long as you have a tune for it the cR will be fine, the biggest issue is the OTS and OE tunes
So what you’re saying is before I buy an aftermarket BOV, I should do my full exhaust, tune and involve the bov all in one no? I’m bome stock. Just trying to add some pep.
Try working for the railroad … trains give me nightmares lol
Smells so rich because you have the valve right open, should be at a minimum 50/50
Great video - what mod's are needed to comfortably use a BOV?
A remote IAT sensor and the proper tune and you can use them without issue 🙏😁
@@Smeedia whats an IAT sensor
What exhaust do you have on your Subie? It sounds amazing!
At this time it was a Cobb down pipe, killer H header and ETS Extreme 🙏
@@Smeedia awesome! I really appreciate it! Great content! I’m looking forward to seeing more!
Bpv delete for high pitch PSSHHHHH-STUTUTUTU ezpz
I had my wrx tuned by my tuner with the gfb response bov it was tuned with it open to atmo before tune ran so bad but I agree it does cause knock and idled so bad now it runs perfect now after tune
As long as you at least pair it with a produce you will be fine, glad that it's running better now! 🔥😁
SO MANY VIDEOS! SO GOOD!
🔥🙌🔥😁 appreciate the support 🙌
time for me to remove my blow3 off valve same issues lots of pops sounds could but now i know why the knocking and the smell.
still, a newbie would put on a bov because it sounds 10000000x cooler.
Hehe
Really get why you would think it would change the idle lol. But good video anyway
So when can you get a BOV? What supporting parts do you get?
I get that it's an MAF based engine. I have a stock tuned STI that I recently picked up with a 50/50 valve and an ETS front mount and an intake. Knowing how anal everyone is they are probably gonna die just reading that sentence. Yes I do plan on tuning it. The ONLY thing I've noticed vs driving my friends pro tuned car with a fully recirculating valve is that once I get near atmospheric pressure (0, no vacuum or boost) the car does tend to kinda stumble a little. Though I'm guessing that's more of the fault of the intercooler. The car has never smelled rich, even with a muffler delete on it. Never stumbles at idle, no dips at idle, nothing. These valves ONLY open once you reach boost. Sure you went into launch control, but boost is pretty low on that. Not only that, there was no apples to apples comparison here. What were the numbers before the BOV? The title is also "don't do this to your STOCK Subaru" my guy, your car is pro tuned and is far from stock. I don't see how your trying to make an argument when there are other people who aren't experiencing these issues, or if you have or have not experienced them yourself and if this is all just speculation. Also modern cars knock, ALL the time. The knock sensor is there to help find out if it needs to lean or rich the system to prevent it. The cars ecu makes the adjustments necessary. I'd bet that if you would let the ECU learn more, it would run better, instead of letting it idle for 5 mins, doing revs / launch control, going back and forward 2 or 3 times, and then saying "yep, BOV bad, only do recirc valves"
I installed turbosmart 50/50 on 22wrx, it stumbles if you're stationary rev and vent.
Watched your vids... Amazing... Got a 2019 wrx stock, i did put the gfb bov and have it at full recurc. I feel the car jerky at times. Should i go back to stock bpv or upgrade to aftermarket bpv and take the loss. 😬
Dope!! Thanks for actually showing it n seeing what happens.
Figured the best way to present the information would be to actually show it 😁 appreciate the support and feedback!
Im a ricer that wants to run a bov and muffler deletes on a stock sti 😭😭
Thanks for this video!
Anytime! 🙏🙏🙏
I am brand new to the gas car society, got a 2017 STI and I love the sound of your exhaust. First question, what kind of exhaust and what do I need to run that exhaust like a tuner? I had to have a tuner on my diesel to run a straight pipe. Second question, what do need to do to the engine to install a BPV or BOV. Thank you so much.
The exhaust was a Cobb catted downpipe and an ETS Extreme catback, all you need to run those is an accessport. You can install a BPV without needed to tune but a BOV will require at minimum a protune 🙏
@@Smeedia thanks brotha I appreciate the feedback!!
I have the same "black" OBEY hat! 😂😂NICEn