soo after about 6 months of dealing with bad gas milage among other problems that may have been cause I put my stock bov/bpv back on today. I must admit that the car runs alot smoother now and shifting is alot smoother. Im gonna see how my gas milage is effected and ill post what the difference is. btw my car is a 2005 wrb with about 4000 miles on it and a turboxs up pipe and turbo back with standard/magnaflow muffler. with the bov i was averageing about 200 miles with about 1/4 tank left. i was running an hks ssqv. u guys/girls think that it was a good decision to take it off? i know the sound was cool, but it wasnt worth the possible damage that could be caused.

 

Did you adjust the BOV to improve the performance? I heard the SSQV comes ready for JDM-Spec WRX not to USDM specs... Personally, I love the sound of a BOV esp the SSQV, and that instance of running rich shouldnt decrease your gas mileage by much, its just between shifts, and its hardly anything, provided that your BOV is properly tuned to your car... let us know about the mileage difference...

 

Is it just as loud?

 

it should be quiet

 

jeez.

i WISH i got that kind of milage!

i guess that's what having a vf23 and a heavy foot will do...

 

i was in the same boat as you buddy. it was pissing me off having such bad mileage. when i filled up, i checked my mileage and i was getting abou 15.5 MPG all stop and go traffic with the HKS bov.

I put my stock BOV back on and now i'm usually at about 17.8 MPG all stop and go.

Don;t mean to hijack your thread but does the recirculating kit for the HKS bov still make any sound? i mean, is it comparable to it when its venting 100%? i always wondered about this but i never got to hear it.

 

an atmo vent BOV should not effect your gas mileage...

your car is running rich not because it's adding fuel, but because it doesn't have enough air..

the air has already been calculated by the MAF, so it knows how much fuel to add in, when you release the bov it's just losing all the air that has already been calculated making the car run rich, but not because it's adding more fuel...

 

The most milage that I have was 375 on a full tank. which was about 14.25 gallons of gas.

I have noticed if you dont have a recirculating kit it will affect driveability. or at least a 50/50 bov.... and by the way it will affect gas mileage. Since the computer is programmed for the stock bov and not getting the recirculation and now it is not getting that extra air it is using more fuel.

 

it is not using more fuel, the fuel has already been metered.... and you can't program the ecu for a BOV.. .

 

No one can that I know of, the system(ECU) is programmed for the recirculating air if that is missing the driveability lessens, which in turn pressing the gas peddle harder = more gas useage for the compinsation or lack of air. I may be wrong.

 

The computer sees the MAF first, then uses the front o2 for closed loop fueling. You might feel a bit of a stumble ,but it DOES NOT use more gas. The computer doesn't cause the driver to push the gas pedal harder.

 

pork chop is right. The MAF sensor calculates for the air before its lost so the fuel is already calculated according to the MAF sensor. This is why you should change to a MAP sensor anyway...dont have to worry about that ****e

 

folks, use your brains.

how/why does the car run rich if it does not use more fuel?

the extra fuel comes when ADDITIONAL air must be sucked past the MAF sensor AFTER the BOV vents to atmosphere. this air used to be ported back into the turbo inlet pipe and is now lost, and must be REPLACED by MORE AIR from the intake system through the air filter and it is metered as it goes past the MAF sensor. it is during that time that MORE FUEL gets called for by the ecu.

if you think that means your air filter will get dirtier, faster, as well, then you would be right.

ken
not a hater, have a txs rfl run half the time