bov q

since thee svo didnt have bov is it necessary for me to have one??? im told by my crazy old man that if i put one on id have to block off waste gate... its running fine with just the wastegate ... almost ready for the street!!!

:yahoo:

the bov isnt required. the svo ran with a pressure bypass valve. i dont remember exactly what it is called. the name is in the tech library in the 2.3 turbo swap section. but that valve takes the pressure being applied to the throttle body and blows it back into the inlet stream before the turbo to kelp keep it spooled up inbetween shifts. the bov just does exactly what is says right into the atmosphere. As far as i know, you can only have one or the other, if you had both, they would work against each other. hope i helped!

88gt said:

the bov isnt required. the svo ran with a pressure bypass valve. i dont remember exactly what it is called. the name is in the tech library in the 2.3 turbo swap section. but that valve takes the pressure being applied to the throttle body and blows it back into the inlet stream before the turbo to kelp keep it spooled up inbetween shifts. the bov just does exactly what is says right into the atmosphere. As far as i know, you can only have one or the other, if you had both, they would work against each other. hope i helped!

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im pretty sure the svo didnot come with a bpv it came with a wastegate wich works similar to a bov but it vents exhaust gasses past the compresseor and to the exhaust thus eliminating spool down. from what i understand i would want to run a bpv vs. a bov since a bov will vent intake air ,already metered by vam, into atmosphere causing a rich condition into the next gear. so i guess the question was do ''i need a bpv runing svo computer at normal parameters with fmic and if i do is it neccessary to eliminate internal waste gate or is both a good thing?''... i have a bov that i can converet to bpv.. thanx for all the help guys!!!

i am not exactly sure about that, but my educated guess would be that having both couldnt hurt. if one fails, at least you will have a backup way to dump the extra pressure. they should happily coexist

the wastegate and the BOV/BPV do COMPLETELY different things... they are not interchangeable concepts and most cars have BOTH of them to work correctly.

The wastegate does not deal with spool down. When you reach your target boost level the wastegate opens and passes some of the exhaust around the turbine keeping the boost from rising even further. Without a functioning wastegate there would be nothing to keep the engine from overboosting because all fo the exhaust would have to pass through the turbine.

The BPV/BOV is like this. Without one when you let off the throttle and the throttle plate snaps closed any boost left in the intake between the turbo and the TB has to go somewhere so it would act like a wave and escape backwards through the turbo which would stop the compressor wheel from spinning or it would find another place of exit possibly popping off a hose or doing other damage to some of the components. You use the valve so that the instant you let off the throttle, vacuum opens the valve and lets that extra boost escape to before the turbo eliminating that wave of backpressure that would form.

The difference between the BPV and BOV is the type of engine management you are using. If you are using a MAP (manifold absolute pressure) system then the quantity of air in the system is not metered so running a BOV is fine and venting the extra air to atmosphere has no negative effects. If you are running a MAF (mass air flow) or other metered air system (vane air meter) then you should use a BPV which diverts the air that is already measured in the system back into the air track. This keeps you from loosing any already measured air. With that loss of air the A/F ratio will be thrown off and there will be a stumble as the engine runs rich with the extra fuel that doesn't have the air it expected to burn.

So you will ALWAYS need a wastegate to limit the amount of boost you have, and to run most efficiently and healthy you should run a bypass valve also.

Oh and a BPV/BOV will never limit boost so is not a plausible method of limiting boost. They are designed to hold as much boost as possible until vacuum is activated on the port which is when it is opened and the boost wave is released.

thanx

ok thanx so i will go ahead and run the bpv... but the svo didnt come with a bpv or bov stock right?? cuz i actually had the donor car siting in my garage while i was doing the swap and their was nothing on the intake but the inter cooler...so it ran with only a wastegate
oh yeah im mazdabomber... i had to change my email adress due to school change!!! i cant even sign on my old one any more...