Blow off valve

fd3szhi · January 06, 2012, 11:18:16 PM

I have a hks bov at the moment on twins is there anyway to get rid of the bov so i can hear the waste gate chatter everytime? i seen to remember when the car was still standard on the bov that the mazda fitted i can hear the waste gate on full boost.

unwindcompletely · February 04, 2012, 12:11:03 AM

Quote from: fd3szhi;805320is there anyway to get rid of the bov so i can hear the waste gate chatter everytime?

ahh a common misconception here, in truth no waste gate ever makes the chattering noise, in fact the chattering noise you hear is air escaping from the inlet.

Hope this helped in some way or another

dthebuk · February 04, 2012, 10:28:34 AM

wastegate chatter is bad

turbo chatter is good.

trotter · February 06, 2012, 02:25:22 PM

Ooh, we\'re doing this again!! It\'s been a while since this was brought up last.

The fluttering noise you are after is the result of what is more commonly known in engineering circles as compressor surge. The compressed air has nowhere to go without a BOV when you lift off (the throttle body is shut) and so forces its way back through the turbine the wrong way. The noise you hear is the air flow changing direction many times as it pressurises one side then the other of the turbo.

There is an epic thread on here somewhere about if this is good or not, but from what I know of North Sea gas compressors, it\'s something to be avoided as you can knacker bearings inside the turbo.

Just my 2 penneth, and I know that this will be answered by loads of peeps saying "i don\'t run one", but my opinion is keep it on. You get arguably better performance with it as well.

graeme

dthebuk · February 06, 2012, 02:27:49 PM

isnt the idea that you get better performance without a BOV than with one? Hence raving cars not running them

trotter · February 06, 2012, 02:45:53 PM

Quote from: dthebuk;811199isnt the idea that you get better performance without a BOV than with one? Hence raving cars not running them

I always figured that they were there to get rid of the pressurised air on the downstream side of the turbo, therefore when it goes to spool again it can do it faster as it isn\'t having to work against pressure??

dthebuk · February 06, 2012, 02:51:22 PM

Yeah I see where you\'re coming from, but i think the idea is that with chatter you keep more pressureized air between the turbo and engine, thus when you open the throttle again you\'ve still got some pressure there.

BlitzBoy · February 06, 2012, 03:24:07 PM

Oh no not this subject again, to the OP, do a search Zzzzzzzz bored.com ....... lol