Quick question , possibly dumb question too! What are the advantages (if any) of a BOV on an automatic transmission 97 1800 GSR??? Anyone out there own a auto GSR with BOV? Because of the slight decrease in RPM when changing gears I assume the turbo probably doesnt slow down much. Will the BOV still make a sound?

Cheers for your help!

 

The first atvantage to a bov is protection of your turbo. When you let off the gas just slightly you change the amount of air goinig into the motor. if you dont have a bov where will the air go but back down toward the turbo. That is extra wear on the turbo that you can easily avoid. The second anwser is that depending on how long you floor it the loader the bov will get just like with a stick.

 

Cheers thanks for that. I understand that every turbo vehicle has a factory fitted BOV atleast (not sure if its called a bov or not but anyway) where it releases the pressurused air back just before the turbo. Thats all fine and thanks for clarifying that! With regard to sound, am I correct to assume a bov wont quite make the same "hiss" in an auto transmission compared to a manual? I didnt quite understand the answer above about the loader...

Basically how I understand it is that the bov is designed so that when the turbo is not active (ie after you take your foot off the gas - ignoring rpm at this stage) the basic idea of the bov is to release the excess pressure between the turbo and the engine into the atmosphere so that the pressurised air doesnt get forced back through the turbo (ouch!). So, with an automatic transmission, when it changes gears, theres probably about a 500rpm (MAX) drop so I wouldnt imagine the turbo would slow down much (if at all), meaning the turbo would continue and hence no excess pressure to release. This is my uneducated assumption. Is this correct or do automatic transmission vehicles still have excess pressure to release and hence still produce an audible sound when passing through a BOV.

Man! Does that make sense, coz it sure as hell doesnt to me!
Thanks for any help!

 

what I miss spelled is louder. the sound also depends on what type of bov you get example ssq, rfl. and if you vent to the atmosphere. if what your are saying is true about it only dropping 500 rpm then of course it won't be as loud as a manual changing gears at 7k rpms but you should still hear it.

 

Neenor, Please update us if you decide to do the install. It's just one of those geewiz things I have always wondered about.

 

a bov is actuated by a difference in pressure. Its only going to blow off when the throttle plate closes, another words, when you take your food off the gas. Since you dont take your foot off the gas while flooring an auto, your not really going to be hearing it much. Upgrading a bov is pretty pointless for an auto

 

That was what I was thinking.