Bov's

[xf_turbo]

Depends on the bov noise. If its the std twin recirc bovs then no; not a ricer. If he's strapped a sheepdog or some stupid sounding bov then yes. A ricer.

Bov's only hinder performance; their only purpose is emissions and smooth drive ability.

Watch what occurs to the afm voltage when you run no bov and lift off the throttle.

Run an atmo bov and watch it dump fuel and attempt to stall/bog the car.

Myself. I run no bov; not for the dose ricer noise but for the improved throttle response and instant torque feeling when you grab that next gear at part throttle/normal driving conditions.

I've tried atmo bov to feel the difference but with an afm setup the car bogs a little on gear changes and is a pain in the arse as it always tries to stall when coming to a stop.

Do some research mate and you will find BOV's play an important role in a turbo charged engine. They actually prevent the turbo from slowing down during gear changes so I dont know what you on about with 'improved throttle response'.

And this part 'their only purpose is emissions and smooth drive ability' is wrong also. Maybe niose emissions but not engine exhaust emissions if that what you were refering to.

Joel

[Cubes]

Do some research mate and you will find BOV's play an important role in a turbo charged engine. They actually prevent the turbo from slowing down during gear changes so I dont know what you on about with 'improved throttle response'.

And this part 'their only purpose is emissions and smooth drive ability' is wrong also. Maybe niose emissions but not engine exhaust emissions if that what you were refering to.

Joel

lol.. Another Joel.

I have done much research but not only theoretical research but practical/data logging both on the street and dyno.

Please do block your BOV and take note of the improve throttle response when grabbing that next gear as the turbo doesn't have to refill the ic piping and ic core.

Having the turbo get back up to speed when running no bov is of a shorter time than it is having the turbo already up at a reasonable speed and having to refill the ic piping and ic core.

No bov most definitely does have a lot to do with exhaust emissions. Block the bov off and watch the AFM go crazy on gear changes. It saws up and down which results in excess fuel being dumped in to the motor; you often notice popping and in extreme cases backfiring/acceleration surging when jumping off the throttle. Cruise at 100km/h in fourth, get some decent boost in to it than back off the throttle but not completely; feel the car accel. surge; watch the afm via data logging and wideband and you will see.

Do try it.

Joel.

Edited 08/09/07 01:56 AM by Cubes

[tab]

Will the plane take off?

[nimsie]

This is the Wiki definition:

A blowoff valve is a pressure release system present in turbocharged engines, its purpose is to prevent compressor surge and reduce wear on the engine.

Blowoff valves are used to prevent compressor surge. Compressor surge is a phenomenon that occurs when lifting off the throttle of a turbocharged car (with a non-existent or faulty bypass valve). When the throttle plate on a turbocharged engine running boost closes, high pressure in the intake system has nowhere to go. It is forced to travel back to the turbocharger in the form of a pressure wave. This results in the wheel rapidly decreasing speed and stalling. The driver will notice a fluttering air sound.

I've just fitted a tuner to my ute yesterday and am running a 10 lb generic tune. After going for a play this morning, the compressor surge it alot more than I'm use to.

I don't like hearing the big Shssss that's comes with BOV's but I also don't want my compressor to go: SURGE - SURGE - SEIZE!!

[Dillz]

So bov's are good then, not bad??

[koppers]

Even at 90lb/min or 41kg per minute, a huge 680 grams per second (weight of air) of air is forced at back past the compressor WOW what an unbelievable force of air !!!! That is assuming 900bhp worth of air flow on an instantaneous closed throttle situation going back past the compressor wheel, what amazing thrust loading ! No wonder thrust bearing wear out and compressor wheel snap off due to the massive accelerations involved on a closed throttle as it pulses back down to 0 pressure.

This is instantaneous load to, this quickly diminishes as the turbo slows down very very fast, within 0.5 second it will be hard pressed to deliver half of this flow amount. The loads are small the accelerations due to the WG fluttering are small, these factors are insignificant and are not worth worrying about.

[SCRIBR]

the bearings can take it

dw

[Dillz]

Thanks for clearing that up

[koppers]

the bearings can take it

dw

I was being facetious.

[bk284]

Little bit off the topic but still on BOV. I am looking at getting the replacement Bosch BOV for the T. It is a direct replacement for the original but it is nice and shinny. There are also a few other advantages apparently. If anyone is interested just post uo in the ideas for group buys section. I have already posted in there with bit more info and pics.

Brendan