BoV's installation and operation

[Chipper308]

Hello, some questions, if you could verify that im correct or incorrect that would be great...the topic is BoV's. now where is a bov mounted? on the pipe inbetween the turbo and the intake right??? stock is a soft tubing and not a solid pipe correct?
On the new piping does it match right up without any fabbing?
-when you put an aftermarket on what work entails going into getting them on there? to my understanding greddy comes with aftermarket J-pipe that matches right up.

I understand what a bov does, relieves pressure when your off the throttle and closes when your on it. so reaction time is a big deal, so in lue of that i have read the synapse is one of the best and this would be the one id like to install, if not a Tial. opinions on both? and what lengths would i have to go to to install them on a stock 2g? i dont weld, and i cant learn, its a dead trade to me and im completely 100% untalented in that field and ill just ruin shit

Thanks for the replys, im going out so i wont repond right away!!

 

[RickyM95GST]

The bov is mounted on the pipe between your intercooler and intake manifold. As far as the stock tubing its a hard plastic but the biggest problem with it is that it flattens out in some spots restricting air flow. Whether or not your piping will match up depends on the kit you buy. When going aftermarket just make sure you buy a pipe with the right flange to fit the bov.

 

[cherrymane]

So wood a greedy rs with the bottom adapter fit on a stock set up?

 

[WES_393]

The BOV is supposed to mounted as close to the throttle body as possible, or at least on the upper intercooler pipe. This lets air flow in the same direction it was already traveling, and allows you to use the shortest vacuum hose possible for quick response.

The stock 2g "pipe" is just a plastic joint that runs under the fuse box. It is (to put it nicely) a restrictive and useless piece of junk. The stock 2g BOV just kind of pops in there too, no bolts to hold it down. The Evo 8 BOV is a direct replacement though if I'm not mistaken. But the type of BOV you can use is also limited by the flange type. The Punishment Racing FMIC can only use a Greddy or 1g BOV, not a Tial, HKS SSQV, or Synapse. Those need a flange to be adapted or welded onto the pipe to use.

Whether or not the new piping matches up is greatly determined by what piping you use. FMIC kits like Punishment and VRSF comes with pre-fab piping that will easily install with the use of some silicone couplers. If you order a piping kit from eBay, you might find yourself with a hack-saw and a bottle of RTV trying to get it to fit and seal. This also depends on the turbo you have. If your still running the stock T25, you will need a T25 specific kit. The 14b/16g has a j-pipe that is needed to fit most intercooler kits.

Now how a BOV works is pressure difference. Think of it like a door with a guy on each side. If you have pressure in the top, and pressure in the bottom, both guys are pushing on the door and therefore it won't open. When you let of the throttle you create vacuum, but there is still boost in the intake pipes. It's like one guy is pushing and the other is suddenly pulling, so the door is going to fly open. There is a spring in the valve to keep it shut at idle, but otherwise they work on pressure difference. The manufacturer can't change physics, there is no sense in going with a super fancy BOV if you don't need it. Some do work better than others by design though. A Synapse is going to open faster and flow more than a Turbo XS, but that doesn't mean the Turbo XS isn't going to work for 90% of boosted cars. Your also limited because you need to recirculate the BOV when using the stock MAF. You can't use a Tial 50mm because it dumps the air into the atmosphere, not back into the intake.

And for what it's worth, my knock-off Greddy BOV has been holding over 25psi for thousands of miles. It opens quick and flows enough air to keep the turbo from fluttering. I doubt that a real Greddy would work any better, yet costs much more. So bigger and more expensive isn't always better. Find one that can be recirculated and works well with your intercooler piping. That's all you need.

 

[RickyM95GST]

^^^ ah good point I forgot to mention the recirculate the bov. If you vent to the atmosphere with the stock maf and ecu it will make your car run worse.

 

[2gmitsueclipse]

If you want reliability, go with a 1st gen DSM BOV with an adapter. It is a good upgrade over the 2g plastic one.

 

[Silver71]

If you want reliability, go with a 1st gen DSM BOV with an adapter. It is a good upgrade over the 2g plastic one.

Where can we buy an adapter to work with 2G?

 

[SlickPyro]

http://www.extremepsi.com/store/product.php?productid=21461&cat=0&page=1

There ya go.

 

[RickyM95GST]

Yup I got a 1g bov in my car

 

[Chipper308]

Well okay, i wasnt aware the fmic piping came with the piping that your bov tapped into. in this case im looking at a front mount when ig et back home from florida basically what i know about it right now is it isnt a huge brand, it holds up to 25psi tested, never tested for more. i ts 2.5 inlet and outlet pipes and he says it fits on the car without have to hack anything up.(from the PO) so what questions should i be asking about the bov? i do not want the stock BoV, as unfamiliar as i am yet. i know the 2g BoV is a leaking piece of crap. and if you guys say i have no use for a 'better' BoV than a normal k/o greddy or something then ill just buy a greddy or something and be done with it, now... to replace the MAF do you need to have ecu work done? such as tuning? if so then ignore the MAF question, im not ready to even read into tuning and im not interested at this point. but thanks anyways.

Last but not least, what is recirculating? if you dont mine me asking, to my understanding normally your blow off will vent the unwanted pressure...somwhere else that isnt your intake. so when you recirculate...where does it go if not the atmosphere?

Thanks for the replies guys!

 

[necrotopsy]

recirculating dumps the air before the turbo, but after the filter, on the intake pipe.

in this illistration, in the red circle is the BOV, and the yellow oval is the re-circulation pipe, and you can see where it leads to.

 

[Chipper308]

Aslo! just so we arnt mistaken, some very near future mods im doing are going to be the FMIC, Wideband, Boost gauge and a MBC cockpit. ive allrdy got a 3' turbo back exhaust. 3g lifters. and a k&n intake.

With that said, its not like i just want a small upgrade to my BoV becuase thats the only things i ever plan on doing to my car, i plan on taking it to the max i can before hitting fuel and tuning problems, which is when ill further my knowledge one step at a time, so a BoV that isnt a simple 1g adapter is some what of a necessity

recirculating dumps the air before the turbo, but after the filter, on the intake pipe.

so.... the car would run worse becuase? sorry if thats a dumb question but im not grasping. if it is dumped into the atmosphere or the dumped back into your clean air supply, either way it doesnt see the intake and the ecu doesnt need to account for that air anyways... right? again sorry if your slapping your foreheads

 

[necrotopsy]

the stock ECU assumes that the air from the BOV will be put back into the pre-turbo intake.
When you dump to atmosphere, the ECU doesn't know you're doing that, and now you're missing air that the ecu assumes is there. you'll run rich between shifts.

 

[Disturbance]

Not to get off topic but without the BOV recirculated could it cause your car to run rich under boost?

Ok as soon as i posted my question you replied and answered it, haha thank you

 

[Chipper308]

yes so.... atmosphere or not. isnt that the same thing? either way whatever is recircluated never sees the engine right? so theres nothing to be accounted for to make your vehicle run like crap, i understand your vehicle WILL run like crap. im just trying to understand why. either way it seems like the same thing to me. its getting rid of air not used. and if it wasnt being shoved backing into the original air supply should it just take more from the atmosphere anyways?

Either way i feel like the factory build on these is absolutely retarded and things are just being complicated to be complicated... WTF

 

[Disturbance]

The engine does see the air when its recirculated, it dumps the air into the intake pipe instead of just into nothing, your ecu expects that extra air to go to the engine so it puts fuel to the cylinders, this is what causes it to run rich because that air wouldnt be there if its dumped to the atmosphere

 

[necrotopsy]

yes so.... atmosphere or not. isnt that the same thing? either way whatever is recircluated never sees the engine right? so theres nothing to be accounted for to make your vehicle run like crap, i understand your vehicle WILL run like crap. im just trying to understand why. either way it seems like the same thing to me. its getting rid of air not used. and if it wasnt being shoved backing into the original air supply should it just take more from the atmosphere anyways?

The air IS supposed to be put back into the engine, that's the whole point of the recirculation pipe.
If you vent to atmosphere, then the air ISN'T going back into the engine, but the ecu will THINK it's there and ACT like it's there, even if it isn't. Same amount of fuel, but less air = rich environment.

 

[Chipper308]

Yes, the air IS put back into the engine, that's the whole point.

sorry we was posting back and forth too fast, i posted that fbore i read your previous... i get it. thanks i appreciate it...BUT i still think thats ridiculous and a waste of time. i guess i dont understand why they would pull something like that instead of just venting to atmosphere...

So without tuning is it possible to vent to atmosphere or is that a post tuning thing? im assuming you cant just tweak the MAF?

 

[necrotopsy]

now this is where my 4g63 knowledge starts to dwindle.
I know you can swap for a GM maf with a translator.
after a quick search, this is what i found

You can run the GM MAF with the translator or run a GM MAF directly to the ECU if you have EMCLink and one of their GM MAF cables.

ECMLink is tuning software by the way.

Here, read this also

http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/174055-everything-you-want-know-about-maf-translator-maft.html

 

[Chipper308]

now this is where my 4g63 knowledge starts to dwindle.
I know you can swap for a GM maf with a translator.
after a quick search, this is what i found



ECMLink is tuning software by the way.

Here, read this also

http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/174055-everything-you-want-know-about-maf-translator-maft.html

Well Crap i guess this means i might be forced to put a second rate bov temporarily or look at some of the "Self-mods" on this site to make my bov not leak until down the road when i start familiarizing myself with tuning software(probably going to end up going with dsmlink, but again i havnt researched this enough)

Haha Well thanks man, appreciate it. ive been in florida for a week now and i havnt been able to look under the hood lately, and for whatever reason bfore this arcticle i was under the impression the stock vented into the atmosphere(which id of figured out if i was at home) good time to read!!! but whatever the case, thanks for the replies haha

 

[WES_393]

There are lots of good/cheap BOV's that can be recirculated. Knock-off Greddy being one of them. Basically anything with a 1" or so "snout" on the end of it. That will allow you to run a hose from the BOV back to the intake. There's nothing wrong with recirculating and I would hate to see someone go through that much work just to avoid it. The reason not recirculating cause problems is this:

When then car is accelerating and boosting, air is being pulled through the MAF and "counted" before entering the turbo. When you let off the gas, all that air is released from the intake. The MAF already counted the air and the ECU expects that air to eventually get to the engine. If you blow that air out into the atmosphere, you just lost the counted air and replaced it with even more counted air. So the ECU thinks it needs to give the engine tons of fuel to compensate for all this air it just counted. However, that air went into the atmosphere and not the engine. So you run rich when shifting.

It is kind if a silly thing, but it's necessary with a MAF. So unless you modify the MAF system to work around it (GM MAF), or eliminate it completely (Speed Density), just work with it. It won't hurt performance or severly limit your options.

Also, I can tell tell you that you won't get far with the stock fuel system. Maybe 20-30hp over stock with a boost controller. You will need a better turbo (14b/16g) and some fuel upgrades (pump/injectors) to make anything over 250hp. DSMLink is also the way to go for tuning. Very easy to use and still powerful.

 

[Chipper308]

There are lots of good/cheap BOV's that can be recirculated. Knock-off Greddy being one of them. Basically anything with a 1" or so "snout" on the end of it. That will allow you to run a hose from the BOV back to the intake.

Also, I can tell tell you that you won't get far with the stock fuel system. Maybe 20-30hp over stock with a boost controller. You will need a better turbo (14b/16g) and some fuel upgrades (pump/injectors) to make anything over 250hp. DSMLink is also the way to go for tuning. Very easy to use and still powerful.

yeah im dreading the whole tuning and what not. im used to the screw and spring method in an engine bay that you could fit 3 engines

an off topic Q i have is as far as dsm goes, is this a... mod? something you send in for an 'pgrade and get it back? ima hit up the search bar soon as a hit send on this

 

[WES_393]

Yes, DSMLink is a modification the the factory ECU. It allows you to hook a computer to the ECU and edit the values. Fuel adjustment, timing adjustment, things like that.

 

[Chipper308]

Yes, DSMLink is a modification the the factory ECU. It allows you to hook a computer to the ECU and edit the values. Fuel adjustment, timing adjustment, things like that.

okay so... i read up on it, and im dumbfounded...i got my work cut out for me. is this a program that ultimately is on your computer? jack into it with your laptop and aUSB and do work from there?? where is this done? i mean where is the ecu sent too? or do you buy a whole new ECU? and ive seen the term socketed? if your ecu is socketed does that just mean all you need is the hardware and the program and your good to go? bcuz im assumed dsmlink is something thats physically installed on your ecu right?

 

[WES_393]

Yeah, it's a bit confusing. I was lost too the first time I read about it.

You basically get a chip installed in the ECU. Since you have a 97, you'll need a bit more work than socketing. You just send your ECU to the guys at DSMLink.com. For a small price, they will do all the work needed so that the chip can be installed. Once the chip is installed an the ECU is back in the car, you hook up a computer to the OBDII port. You have to download the program (which is free) in order for the computer to connect to the ECU. But once your plugged in, you can adjust the factory settings with your own laptop. The chip will save the changes for you until you edit them again.