does anyone know what kind of bov this car has,

http://youtube.com/watch?v=HqbyDH_HCTE

 

I don't think they are running a bov. Sounds like compressor surge on a ball bearing turbo.

 

hmm compressor surge is bad though, right?

 

it's not good.

 

A compressor surge, typically, causes an abrupt reversal of the airflow through the unit, as the pumping action of the aerofoils stalls (akin to an aircraft wing stalling).

they have websites that have sound clips of different bov.

 

pretty much compressor wheel spinning at over 100k RPM's in a fraction of a second is now spinning backwards....



not good..

 

not necessarily backwards, though it can. yeah that sounds like compressor surge jsut for the fact that the sound lasts so long

however, i think its a tial BOV. and just to prove my point (but my buddy has one on his DSM they sound very nice and unique) here is a vid http://youtube.com/watch?v=tXqgTtHECnk

sound is the last half

 

It sounds good, but yeah, that does make it hard on the turbo...

 

That's surge up the yinyang on the 240sx, there isn't a bov. Take a look when the motor is on the dyno. There is no bov there anywhere on the piping. It's straight compressor surge is all you're hearing. Go to a D1 meet and most of the pro Japanese drivers do not run one either. Their cars make the same exact sound. I know Taniguchi does not run one for sure.

 

even though i agree you cant see one, if you look on the cold charge pipe section, you can see 2 ominous looking cylinders that could be on the piping or in the background conviniently located.

 

If you're talking about that flappy-sounding noise, that should be a wastegate that's dumping direct to atmosphere.

 

nooo... wastegates dont make noise when you let off the throttle, they open only under full/near full boost. and they just open exhaust into the atmosphere if they have an external dump tube, and they just sound like a louder more uncontrolled exhaust tone.

 

Ah my mistake then. It can be misleading when are videos about wastegate noise like these:

http://youtube.com/watch?v=rhrqiOowORY

http://youtube.com/watch?v=mX6qJb8Pw_Y (at 28 secs)