I'm liking this new series and how technical it is. As mentioned in the video, it's good to get a professional opinion that isn't some bloke on a forum site.
The answer is yes. I recommend getting a GFB TMS respons hybrid BOV so that way you can vent whatever percentage you want and won't trigger a check engine light
so when venting to atmosphere the mixture becomes rich meaning not all of the fuel will be burnt dumping un-burnt fuel to the exhaust where if sufficiently heated may cause it to reignite.... AKA shooting dank ass flames
Carmicha3l it vents when throttle plate is closed and there is fuel cut off when throttle closes therefore not dumping much fuel with an atmosphere blow off, as explained in the video
If it is so unhealthy to run the engine rich then why do a lot of modified cars (including mine) run on decel ignition cut and not decel fuel cut? It didn't blow the turbo on the Subaru and it doesn't wreck your engine. Please provide me with facts towards your argument.
That 2 port blow off value was the best item I purchased for my rexy. Made the best sounds, and when I got pulled over, I just quickly turned it to 100% recirculation and got away defect free :)
@@moto324 i have a proceed GT and haven't noticed my car to backfire any more than it already does. I have it half open, and i keep myscrew driver handy, in case I need to adjust mine, as it has a manual adjustment lever, not fancy remote control haha. The GFB DVX is what I have.
fun fact, Brett means Wide in Swedish, so go fast Brett in Swenglish translates to Go fast Wide, as in when you drift. or "åka på tvären" as we say here. great series btw
Awesome video guys, love that you are helping to clarify issues you've found on the internet with people that actually know what they are talking about!! I was just wondering if you could clarify how you would go about determining the correct spring tension for your b.o.v in order to not cause stalling or backfiring. I.e how do you go about setting it up correctly ?? Cheers And love the videos !!
Good video I found it was just easy to move the maff after the blow off valve that way the air that is being discharged never passes threw the mass air but yes most GM that I tune have DFCO deceleration fuel cut off as soon as your foot leaves the pedal your AFR is flat lined shutting off fuel. When tuning even in open loop with DFCO disabled still don’t see rich conditions even if so a little extra fuel will keep them cylinders cool lol thanks for the info brother God Bless
I've been trying to figure this out for 5 hours today and finally stumbled on this video. I have a 2014 Jetta GLI Autobahn (GEN3) and the forums are just like you said. Looking for a dual port valve now. Thanks
You mean speed density off of your MAP. I have a Speed 3 and we have MAFs and MAPs. But our air is metered at the MAF, so we end up venting metered air, getting idle bounce, afterfires, etc., esp if you're venting too much. If you vent just a little, you're usually okay.
Some people's MAF and IAT are sort of spilt up, you can move your IAT right before your manifold after the BOV. Then delete the MAF with a MAP based tuned. Obviously only can do this if you have a MAP sensor on the intake somewhere. Boom problem solved.
i'd like to see a follow up of this covering the differences between EFI systems using MAP sensors instead of MAF sensors and also Blow through Carby setups.
Intestine video! On the turbo system that's on my Focus, the blow off valve is before the MAF so it makes no difference to idle or AFR when I vent to atmosphere. I'm also using an OEM diverter valve off of an Audi, and seems to work just fine as well. But of course, I specifically designed the system to have all of the venting stuff before the MAF so I could avoid all of these problems. But I don't know if most OEM turbo systems work that way, so probably trust Brett ;)
I had an 09 STI with one of these GFB BOVs on it and a Cobb intake. I had tuned it with the Cobb accessport and wasn't running a really aggressive map (just stage 1, low wastegate), but had ringland failure after about 15k miles. The Subaru dealer was cool and did a warranty repair on it, but really thought it was do to a rich mixture that the engine failed. As he said in the video, make sure you get a GOOD tune if you put one on.
I think it did, but just not quick enough, so it would get just a bit rich on lift. Like a lot of people said, Subaru's are really sensitive to MAF. I recently got a 2015 STI, and did basically the same tune, but minus the BOV. I'm 6k into it and a couple track days as well, so we'll see what happens.
if it goes to atmosphere its more of a "psssh". My 180SX has a bolt in the end of a bit of vacuum pipe on the intake and that goes "sututututu" really fucking mint-ly. no bov at all
What I've always been told is that it might gunk up your first catalyser. That's it. The unburnt fuel will just gunk it up over a (very) lengthy period of time, after which you either change it or just cancel it lol. I prefer keeping them as I'm not a fan of smelly cars, and they are a few hundred bucks I beleive, but yeah if you go with a 50-50 valve... You should be fine. I had one on my '04 WRX, and even tho subarus are reputed to not liking BOVs too much, with th 50-50 one, I had it on the car for 3 years and everything was still perfectly good.
Newer into the car scene & just grabbed a GFB TMS for my WRX. 50/50 was my plan anyways based off of still having air recirculating and still getting the atmospheric venting “pssssh,” but after seeing your comment I feel a lot better about it, thanks for taking the time to leave your opinion 5 years ago LOL
We've tried many BOV on a Mitsubishi Evo, the best performing one is actually the factory one. It leaks just enough air so you don't get compressor surge, and you can tune it so the recirculated air with some negative ignition timing will give you mega pops and bangs from the exhaust, as in blows the exhaust gaskets to pieces lol. sounds better than a BOV any day
You can still get a nice Whoosh sound from a bypass valve if you have a pod filter attached to the intake of the car, especially if you've replaced the factory rubber inlet pipe with a metal one. My 1.8t a4 makes a nice audible bov sound and it's fully recirculated.
+1 this. I have a K&N panel filter in a CDTi airbox on my Z20LET in my Astra, with a TurboSmart reciculating valve, and it is clearly audible. Not as loud as if I were to use a pod filter though, and definitely not as loud as a vent to atmoshpere bov.
I think he is talking about a specific car manufacturer. Fords along with every other car company that I have seen under the hood have a mass air flow meter after the airbox, NOT before it. I took the recirculation hose off of my 2022 Ford Bronco 5 months ago without issue.
The recirculating bov will actually push air backwards across the MAF depending on the boost pressure....thereby still creating a rich condition as the air is metered twice. This air pressure wave will also blow backwards through your air filter.
If you plan on setting up for flat foot shifting than I would say a recirculating BOV is better. If you are not doing that it doesn't really matter. Having a vent to atmosphere BOV can also cause backfiring when you shift or let off the gas. Backfiring and shooting flames out of your tailpipe is nifty.
I have a turbo kia forte and I disconected the reserc tube amd pluged the intake, no problems at all. Most CAI come with BPV deletes for it anyways. All depends on the car and i love my kia
It really depends if the turbo vents upstream or downstream of the MAF sensor. I had a 21 bronco that vented upstream and swapped to vent to atmosphere and never had an issue. However, I could see how venting to atmosphere with a turbo after the MAF could potentially be a problem...
Nice quick video and spot on. I'm told it's flat out illegal in NSW to vent to atmosphere, which is ridiculous. Do you know whether that is true Sir GFB? My car is supercharged, blows through a throttle body and uses MAP (amongst other things obviously) to determine fueling. Why should my bypass valve be illegal because it vents to air? Is it also illegal if I disconnect the intake pipe? Because it's the same thing essentially. So by the same logic, it must be illegal to have an air pump attached to nothing. They should be thanking me because I'm running that air through my air filter and huffing it back out. I'm HELPING the environment!
hybiepoo probably you have told wrong, the only thing I know it's illegal is blow the oil breather hose straight into the atmosfer, that way you are blowing oil vapor that goes to the intake manifold in a stock car
I want to fit a blow-off valve to my turbo vehicle, do I need a modification plate? Fitting a blow-off valve is considered a minor modification and does not require approval. When fitting a blow-off valve, it must be vented back into the vehicle's induction system. Blow-off valves that vent directly to the atmosphere must not be fitted. www.tmr.qld.gov.au/Safety/Vehicle-standards-and-modifications/Vehicle-modifications/Frequently-asked-questions-vehicle-standards-and-modifications.aspx#blow
Some VW 1.8 turbo and 2.7 biturbo has vacuum reservoir and N249 solenoid for DV to pert it at part throttle. If somebody want to swap to aftermarket blow-off without recirculation then must disconnect this vacuum system and connect it directly to intake manifold.
FYI This entire topic/video pertains only to EFI and excludes carbureted vehicles. In fact when you run a BOV on a blow through carburetor this allows you to jet the primaries down which helps with fuel consumption. Even at 6 PSI still run a BOV.
I ran a vent to atmosphere BOV on a nearly stock Nissan SR20DET engine with a stock ECU and MAF for a long time,and absolutely never had any problems because of the BOV,whatsoever.
It's only metered air if the BOV is behind the MAF. On a SC compressor setup the MAF is usually behind the BOV which means you can vent to atmosphere and not impact fuel.
If car has MAF sensor yes, its should lead to momentary rich condition and rpm spike and cat clogging. But if you have a MAP sensor, it doesnt matter. Also if you drive your car hard often enough you can usually get the CAt hot enough to burn off deposits
I don't disagree with any of this, but there's something that's overlooked every time this is talked about. Every mechanism, port, valve, etc on the inside of the intake is protected by Factory design, by a simple air filter. If you run your valve to atmosphere, the components of your valve are now open to dust, engine heat, grime Etc. And if you run a piston type blow off valve like I've installed, its really just tolerance on the cylinder wall and Lube to get the tightest seal out of the internal cylinder. Lube attracts dust. Your valve May wear out quicker. If you run a diaphragm type, you are subjecting that diaphragm to engine heat possible dust fumes Etc that will make it dry out and crack and leak sooner . Thank you so much for this video it's a hundred percent correct, this is Just a point that's always seems to be overlooked, but in my opinion worth mentioning as I try to build my projects to outlast my great-grandchildren with as little maintenance as possible.
Perhaps you could walk us through how this would affect an engine running without an air flow meter? Like with aftermarket ECUs and some OEM's, like Saab Trionic 5. Since these systems doesn't calculate fuel based on air flow, surely they respond differently to the use of atmospheric BOV's?
The bov only opens to release pressure that the turbo/turbos create by still spinning after the throttle body is closed. Manufacturers only use recirculating diverter valves to deaden the sound. It makes no difference if you recirculate the air, or vent it to atmosphere.
Shane Hubert Look, I’m not a genius expert on turbos but it doesn’t take a genius to have common sense. A blow off valve is getting the air from a turbo and throwing it to the atmosphere. Then when you are on the gas again the it’s throwing enough gas for the air that was supposed to be recirculated. It’s gonna give you a lag, then it’s gonna give you backfires because there’s too much gas. If you’ve driven any turbo car, put a BOV on it. It’ll run rich without a proper tune. Even with a tune I hear it won’t run 100% healthy. There’s a reason why the companies that make the BOVs put “Tune required”....
@@WheelsAndBusinessVlogs no, it's excess air that can either be recirculated, or vented out, your car doesnt just throw random amounts of air in no matter where it comes from. By that logic, when you get a bigger turbo and it takes much much longer to start making compressed air, the car would just run like shit and run rich, that's not how your engine works. It maintains an air to fuel ratio.
Thanks, most people don't even know what a stock one is. Good answers. I'll stay stock, not worth changing ,just to hear engine noise between shifts. Looking for power/ fuel economy. When I got my SONIC 1.4/6-sod. Wanted a ,"GASCAR."
Surely to solve all issues and problems it would be best to use a map sensor over a maf as this would read the pressure in the manifold and the ecu would adjust the fuel accordingly??? if your modifying a car make it safe and do it right
brilliant video, and thanks for not wearing a black tshirt and looking like a floating head and arms with a black background. really intersiting video, and great to hear some talking sense. ok random question. can you put a Blow off valve on a turbo diesel, venting to atmosphere a engine with a Ecu and an engine without an ecu its for a show car i just want it to go woshhhhh.
I tried this on my 2016 expedition. She ran a little warm, the whistle sounded more like a rush and the boost maxed from 15 to 16 psi. Do with that what you will.
So in a nutshell the only reason you vent to atmosphere is for the sound and best case scenario it doesn't really do damage. Worst case it makes your car shitty (bad idle, backfires,stalls)
It makes your car run like dookie if you don't have the right balance point. With my RDX I have to do a 70/30. 70% back to the intake 30% to atmosphere
Another key point, if you are drifting for example and require to be going on and off on and off throttle many times successively, it can in fact cause a stall/flood condition upon lift off. So if you're drifting you need it recirculated, or you need a standalone MAP sensor conversion. For street or track use it doesn't matter but it does for drifting. My drift car when venting to atmos stalls out after a while of drifting due to constant BOV activation so I just recirculated it and problem fixed.
Actually if you know good tunner, you can "turn off" DV in ECU. It will not count air vented into atmosphere by BOV. The. It will work awesome. 1 thing, with bov you have little bigger lag because of vented out air from the system, but on the other hand, turbo will live longer. BOV is ok when your car is far away from stock. Flyes away
a BOV is absolutely fine to use, especially when OEM versions can be really bad! But the best way to go it recirculation! BTW I didn't watch the video, I wanted to add my comment seeing that this video keeps stalking me!
Prime example, on an ecoboost f150 the blow off valve tube connects after the mass air meter. With it like this there are no extreme rich or lean factors within the motor. And that is with the factory location capped off. Only difference is you don’t have useless vapors recirculated through the engine. Hense factory setups usually collect enough moisture within the inteecooler which cause the infimous hesitation on fords that people complain about. Let the crap vent and save future issues
My brother took his recirculating blowoff valve off his 97 forester 5 SPD manual and everytime he stopped at the lights it would stall 😂 I have a auto version I'm still going to try it out 😂
no mention of part throttle i.e on track cars mid corner, as i had overfuling issue on my mx5/miata turbo before i went with a stand alone MAP based ecu.
So if you position your BOV so that it vents to atmosphere before the air passes through the MAF, then the MAF will be reading the amount of air entering the engine correctly.
One thing I wish were in the video was talking about the autocorrect aspect in most oem ecu's. Factory ecu's usually adjust the mixture a tiny bit if it thinks that the mixture is too lean or rich and it's usually just an adaptation factor and once it reaches a set percent it will cause a CEL. eg. ~15% in Saab's . Could a BOV be enough? (I kind of doubt it unless you drive really erratically) So mostly you'll get it for various other reasons, eg. an air leak. But could a bov cause it?
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