Actually the main reason why BOV are re-circulated back into the intake track on stock cars is beccasue the turbo is located after the MAF. Because the MAF has already metered the air when the throttle plate closes and you need to put the air somewhere releasing it will cause a major rich condition. Due to the ECU thinking that the air you just expelled is going to the cylinder as a result of the metering pre turbo. usually when this is done the air is re-circd back into the intake pipe after the maf but before the turbo. This can cause SOME very SMALL turbulance issues. In BIG HP applications where the CFM of air moved by the turbo is that large recircing can cause HUGE probs as a result of both turbulance and efficiency is reducing compressor surge. That why in any big powr application they vent to atmosphere. Or the other reason is if the turbo is before the MAF> IE the Turbonetics kit. Becuae the compressed air from the turbo is actually being metered by the MAFwhen the throttle plate closes you can vent to atmosphere as long as the BOV is located before the MAF...

 

i don't know if it is possible, but would moving the BOV "infront" of the MAS help to reduce the likely hood of running rich? if someone has already said that I apologize then for the repost. Are there kits that put the BOV "infront" of the MAS?

 

See my post above...

as for putting a BOV on a non-turbo car...No it wont do anything and even if it did your new name would Ric-a-roni

 

from all cars that i am familiar with, all the MAFs, AFMs, MAPs are positioned before the turbo, and the bov's are located on the pipes comming from the compressor housing. so to position it there would defeat the purpose.

 

What if you are using a standalone that replaces the MAF sensor?

 

Well there are more setups then you can imagine trust me...

Heres a pic of a Spec V turbo kit configured as I described... the recirc valve vents back into the intake AFTER the MAF but before the compressor..





Heres a pic of the Turbonetics turbo with the MAF metering the compressed air... Note BOV is between the MAF and the outlet pipe...






Likewide with the APS kit



In fact the only time you can vent to atmosphere with a pull through type turbo setup where the MAF is pre-turbo is if the ECU can correct for it... On a lot of factory turbo cars a MAP is used. In this case you can vent anywhere you want as the air is not metered as it enters the motor. The ECU checks the air by utilizing a pressure sensor in the intake track. This is the set up most Hondas use...I cannot speak to what MR2s use but all the pics I have ever seen do not show a MAF therefor it leads me to believe it is a MAP based ECU...Usually in high horsepower based kits where the MAF is before the turbo the MAF voltage is clamped and it is using a MAP sensor for tuning. If it does not you will most certainly have a rich condition when venting to atmosphere unless the ECU is somehow accounting for the air it already metered being expelled.