BOV Location

[robbbby]

Which side does the blow off valve go, piping from the intercooler to intake manifold or piping from intercooler to turbo (hot pipe).

I thought it went on intake side but I just saw a picture with what looked like a BOV on the turbo side.

[Sintax]

this topic has actually been discussed quite a bit, you may want to use the search function before posting.

but different tuners have different tastes on the subject, search and see what some have said.

-scott

[BuudWeizErr]

It seems to me that having it on the IC -> IM would be smarter, but when I think about it, it doesn't seem like it would matter much. Thats where my buddy has it mounted on his SR, but I've seen it on the turbo -> IC pipe.

Is it just a matter of preference?

[SrSLeePeR]

I have mines between the IC and the copressor...I have a GReddy FMIC, and a Type-S BOV and it sounds pretty dayam good. It's tucked in the fender and it shoots out through the pasanger front side marker location...

[RedStage]

As long as it's in between the turbo and the Intake.....it's all the same......

The big issue is...

Wheter it is a BOV that vents to the atmosphere or back into the system. A closed BOV is actually better....just doesn't make as "Cool" a sound.

[SpeedRacer1]

From what I can tell there is no specific effect that happens after someone installs an atmospheric BOV, blow off valves have different effects from car to car.

Maybe one day we can start a thread about it.

[matt240det]

i'm putting mine on the hot pipe for the simple reason it iis closer to the inlet on the turbo to re-route it, no venting to atmosphere for me you will run rich in between shifts because the mas is calibrated to have that air and it also helps spool your turbo if you aim it right

[Sintax]

you wont have to worry about running rich if you place the MAF after the BOV, then its metering the TRUE air so your ok.

just something to run through your head before you make any welds in that pretty pretty IC tubing :pface

-scott

[RedStage]

Generally when a BOV vents to the atmosphere, it really doesn't matter where the MAF is...

When it vents under the hood the surge of air is detected by the MAF and it adds more fuel to the mix. Often resulting in a backfire in between shifts.

[Sintax]

Quote »Generally when a BOV vents to the atmosphere, it really doesn't matter where the MAF is... When it vents under the hood the surge of air is detected by the MAF and it adds more fuel to the mix. Often resulting in a backfire in between shifts.[/quote]

now thats an interesting statement...kinda sounds like your under the impressiong that the MAF has an external meter that detects "under the hood pressure". last i checked they did not do that, hence why when you place the MAF after the bov it meters the air that the BOV is letting by and reports that amount to the computer. :thinker

i'd love to be correct if i'm wrong, but this was how we've done it in the past.

-scott

[RedStage]

Ok, so every Japanese mechanic I have talked to in the 10 years I have been here in Japan are wrong. Roger that. Considering a few of them have been Nissan mechanics that have been crew workers for Nissan Racing teams.

Trust me. I have had a CA18DET, RB20DET both with external venting BOV's Both backfired quite a bit in between shifts.

My SR20DET has the stock BOV on the intercooler and it is an Internal venting....No back fires.

If you have an HKS (or anyother Pod airfilter) the surge from the blow off valve will be registered by the Mafs. Unless on the SR20DET setup, you replace the stock BOV with an aftermarket one, cause the stock BOV is in the front left wheel well.

[180crafter]

Kinda off topic, but if that is your car Redstage, congrats. Super pimp.

[RedStage]

Not mine....close though

http://www.geocities.com/velocityyokohama

click on redstage......feel free to check out the other rides.

[JedC]

nice wheels redstage, what size are you running? also anyone know if these can be found in the US and for how much? thanks and i don't mean to steal the thread

[DonDonati88]

I have mines between the IC and the copressor...I have a GReddy FMIC, and a Type-S BOV and it sounds pretty dayam good. It's tucked in the fender and it shoots out through the pasanger front side marker location...

CAN U SHOW us a pic of this setup? thnx

[I H8 UR DSM]

nice wheels redstage, what size are you running? also anyone know if these can be found in the US and for how much? thanks and i don't mean to steal the thread

they look like 15" Wantabee's....$$$$

[I H8 UR DSM]

REDSTAGE, WHATS WITH THE TYPE R DRINK HOLDER???????????????????????????????????????????????????????????????????????????????????????????????????????????????

[SRdS14]

man this is an interesting topic...you learn something new everyday. so ur saying that since my BOV is between the turbo and the IC, its blowing off into the atmosphere causing the MAF to send signal to my ecu and that's why it backfires? cuz it backfires all the time.....i've gotten used to it. please correct me if i'm wrong so i don't feel stupid explaining this to people here....~Scott

[BuudWeizErr]

you have an atmospheric BOV, that's why your car backfires.

A recirculation valve moves compressed air out of the intake tract when the throttle plate is closed and back into the intake, before the turbo, after the MAFS. The pro's are that you won't run rich when you shift, and your car won't backfire. The reason that happens is because with an atmospheric BOV, the MAFS is reading a set amount of air, and the ECU compensates for that amount of air with fuel. With that air not present, the car runs rich, and that is what causes the backfire. A recirc valve doesn't make a cool sound. Thats the only con.

A lot of people have gotten around this problem when using atmospheric BOV's by cutting their cold pipe (IC -> TB) and putting the MAFS in there, in that case, the MAFS is after the BOV.

EDIT: Or you could always switch to a MAP sensor

[SRdS14]

thanks bro.... bump bump.~Scott

i ain't gonna lie though...people love it when a flame shoots out my exhaust after i get off it....

[Silviagirl79]

thanks bro.... bump bump.~Scott

i ain't gonna lie though...people love it when a flame shoots out my exhaust after i get off it....

How does a flame shoot out of your exhaust??? Is this safe?

[I H8 UR DSM]

its not good for your car is you run too rich, ie, 'shooting flames' , but i think you can buy one of those new mullfer tips from autozone silviagirl if u want flames shooting : )

the AFTERBURNER!!! lmao lolohahahahahhaha

[Onizuka]

Ummmm.... backfireing can damage your turbo first of all and thats from gas igniting after it leaves the cylinders. You might think backfireing is ok after seeing rally cars backfire, but that is because they have the money to replace the turbos after every stage.

Also, Ive never heard of a MAF sensor ever being placed anywhere other that right after the air intake, because i dont think it is supposed to be under any pressure. Any way, the only problem i have heard of with atmospheric BOVs is that when you stop your car might stumble or just die out. but that problem is a easy fixed as turning your key.

[SpeedRacer1]

Any way, the only problem i have heard of with atmospheric BOVs is that when you stop your car might stumble or just die out. but that problem is a easy fixed as turning your key.

Stalling usually only occurs when coming off a decent boost when you can hear the BOV giving off air. Its even easier to fix by just tapping the gas barely when you see the RPMs dropping. Then instead of going below 500 it will drop to about 1000 (if done right) and level out at your normal idle.

[Silviagirl79]

Ok, thnx for the replies all. So all in all...I should I get an atmospheric BOV or not? I am going to be installing my SR in late january, pretty stock at first (side mount IC, 3in dp, walbro high flow fuel pump, intake). Then going to add a fmic later on (2months later), I suppose this might be the best time to add the BOV right? What kind?

[Onizuka]

id say if your getting a hot pipe with your FMIC just wait until then and have heavytrottle attach it. I belive they attach the flange for the BOV you want. If your not looking to spend a lot of money just get one of the cheap turbo XS ones.....

[SRdS14]

no **** i know its not supposed to backfire and yes i know its running rich. i'm fixin all that this week anyways...i just said EVERYONE likes it when my car flames.

[I H8 UR DSM]

cheap turbo XS ones.....

Inexpensive would be a better word to use.

[Onizuka]

yeah your right, i have not (edit) heard too much about poor quality for turbo xs

[lucky]

now thats an interesting statement...kinda sounds like your under the impressiong that the MAF has an external meter that detects "under the hood pressure". last i checked they did not do that, hence why when you place the MAF after the bov it meters the air that the BOV is letting by and reports that amount to the computer. :thinker

i'd love to be correct if i'm wrong, but this was how we've done it in the past.

-scott

You are wrong and I'm gonna call you a liar if you say you have done this in the past. The MAF is supposed to be on the intake pipe before the turbo and the BOV is supposed to be on the intercoler pipe after the turbo. Time for you to hit the books and learn how cars work :rolleyes Just get a HKS VPC, Apex-i Power FC Pro or any stanalone and you won't have to worry about stalling when your BOV releases to the atmosphere anymore. BTW...get a Blitz or HKS BOV....I've never heard anyone complain about them.