What kind of BOV are you running?

rjs_speed3

Member
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MazdaSpeed3
Just wanted to know what types of "safe" BOV are out there and available for our cars..

I spoke to a Mazda specialist over the phone, and he told me that if i were to upgrade my BOV, it might create an overboost of some sort..

He stated that our factory BOV was designed to slightly leak.. to prevent an overboost..

Im not too sure if this is true, but if it is, what are the types of aftermarket BOVs that are safe to use on our cars??

THANKS!!!

Peace,
RJ
 
There are two different ways of running a blow off valve or recirculation valve:

Vent to atmosphere - excess air is purged from the system

Recirculation - excess air is transferred back into the system after the MAF.

The stock system is set to run in recirculation mode, this means that any air that is measured by the MAF, once it enters the intake system stays there. Venting to atmosphere will allow air that has already been measured to exit the system, resulting in incorrect amounts of fuel to be injected.

You can make most valves run in recirculation. The forge motorsport BPV came highly reccomended by some members. The HKS system is supposedly high quality as well.

There are numerous posts on this subject.
 
Just wanted to know what types of "safe" BOV are out there and available for our cars..

I spoke to a Mazda specialist over the phone, and he told me that if i were to upgrade my BOV, it might create an overboost of some sort..

He stated that our factory BOV was designed to slightly leak.. to prevent an overboost..

Im not too sure if this is true, but if it is, what are the types of aftermarket BOVs that are safe to use on our cars??

THANKS!!!

Peace,
RJ

The factory valve is cheap plastic. Don't quote me as I have not tested it yet (true on Subaru) but I believe the pin hole next to the valve on the pressure side does allow boost into the valve to begin opening it while building boost. (Edit: confirmed this is true on our speed's today) An aftermarket bov will hold more boost and not open premautrely but not allow the car to over boost as best as I have experianced. The theory your mechanic mazda guy stated is logical but I don't think its true.
 
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So it's between the Forged Motorsports BPV or the HKS SSQV??

Does any of these systems create some sort of a surge??
 
Im running the HKS SSQV and am completely happy with it

if your planning on putting in a BOV Im assuming your going to put in harpipes too? cause you kinda have to

well, if your gonna do that then BE SURE to relocate your MAF sensor to the throttle body intake pipe (the one running boosted air...I cant recall its correct name at the moment)

I know some people say otherwise but when I did it I noticed a HUGE difference in how my car pulled...it no longer had as significant of a 'hesistation' throughout the powerband and it drove all-together better cause of that

basically you should have on your hardpipes from intake filter to car for the relocated setup:
Filter->Turbo->intercooler->BOV->MAF->Throttle body

if your not planning on relocating it then run recirculative, if you do relocate (which I highly recommend) then just run vent to atmosphere...it wont make a difference in that case


as far as a surge, yea it will surge a little but we are talking less than 2 PSI....youll be running around 6 pounds stock, but when you accelerate hard it will jump up to around 7 or 7 and then immediately fall back to 6....not an issue at all, nothing to be worried about...I would only be worried if your car goes over 10 psi
 
Im running the HKS SSQV and am completely happy with it

if your planning on putting in a BOV Im assuming your going to put in harpipes too? cause you kinda have to

well, if your gonna do that then BE SURE to relocate your MAF sensor to the throttle body intake pipe (the one running boosted air...I cant recall its correct name at the moment)

I know some people say otherwise but when I did it I noticed a HUGE difference in how my car pulled...it no longer had as significant of a 'hesistation' throughout the powerband and it drove all-together better cause of that

basically you should have on your hardpipes from intake filter to car for the relocated setup:
Filter->Turbo->intercooler->BOV->MAF->Throttle body

if your not planning on relocating it then run recirculative, if you do relocate (which I highly recommend) then just run vent to atmosphere...it wont make a difference in that case


as far as a surge, yea it will surge a little but we are talking less than 2 PSI....youll be running around 6 pounds stock, but when you accelerate hard it will jump up to around 7 or 7 and then immediately fall back to 6....not an issue at all, nothing to be worried about...I would only be worried if your car goes over 10 psi

In general having the MAF closer to the throttle body will give more accurate readings, however I don't know how easy it would be to put it closer to the TB because of the way we're setup, I'd leave your MAF right where it is. Also, the BOV is connected to a hard pipe, if you moved your MAF to after the BOV then you'd have to drill a bunch of holes in that pipe, which IMO is just not worth it.

The topmount setup has one really nice feature, and thats the fact that we have VERY little piping after the turbo, the biggest restriction is in the air filter and intercooler.

I thought the mazdaspeed3 was running more like 15-16 psi?

The forge units are simple, and already tuned for our cars, all you have to do is screw it on.
 
wow

I REALLY have not been paying attention today haha

I thought this was the MSP section! nevermind me...
 
cp-e has the stand back, and xede has the piggy back...they are ecu for the motor that allow you to tune the car.
 
cp-e has the stand back, and xede has the piggy back...they are ecu for the motor that allow you to tune the car.
I see. Now i am by far an amature at anything car related. I can install the basic bolt ons and also do spring swaps and of course, regular maintenance. What does tuning consist of? As in, what kind of knowledge would one need to know.
 
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