Fluttering is … With the throttle body closing, pressure builds in the InterCooler tubing and backs up back into the turbo since the bypass route stays closed, causing increased strain and rapid/forced deceleration of the turbine wheels inside the turbo. - posted in Under the bonnet: i disagree .ive not had much practical experience with them but in theory it should reduced boost drop off during gear changes..or at least reduce the time for the turbine to spin back up to speed ..The BOV has absolutely no effect on turbo spool-up times. 14-05-2012, 05:26 AM. The good: nothing. The easiest way to create turbo flutter is to remove the blow-off valve. Pretty much if your BPV/BOV doesn't open early enough when you close the throttle plate the back pressure hits the turbine wheel and causes the blade to slow/stop/go backwards which makes the noise. So to the OP, what you want is to either block off the standard BOV or buy one that's adjustable and wind the … The only problem is that this flutter is extremely unhealthy for your turbo. Taking that into account means that the compressed air would have to create much more force than the exhaust to create a stall event in the turbo. While you won’t find a mechanic that recommends this, it’s unlikely to cause any damage to your vehicle if you aren’t creating loads of backpressure. The turbo flutter noise is caused by having no blow off valve (or having the spring pressure set so high on the BOV it doesn't open except under high boost pressure). Lol @ James Flutter through a VTA blow off valve is caused by variations in plenum pressure when the throttle is released. Join Date: Oct 2011; Posts: 5240; Share Tweet #2. When properly adjusted, the valve should make a clean PSSSH or Whoosh sound when venting a significant amount of … compresosr surge. I thought the fluttering he was referrring to is the air fluttering agaist the compressor ie. Don't worry, your turbo is okay. The bad: everything. do you think you guys could do an episode on turbo flutter? You're getting the flutter (like a Supra) because your car is not generating enough vacuum to lift the rubber diaphragm (assuming you have the OEM 710N Diverter) and not letting the air escape. This can cause premature wear on your turbo, however closed throttle flutter on modern turbochargers is unlikely to cause a noticeable drop in turbocharger lifespan. oh, the fluttering you are referring to is the bov fluttering. With an aftermarket BOV fitted some non-detrimental low rpm fluttering does characterise certain cars (as mentioned above) particularly where a larger turbo and intercooler have been fitted. Also given the housing and wheel sizes, the turbine size is generally smaller as it is made to make maximum use of the force from the exhaust vs the larger compressor side. It happens MORE with bigger single turbo's as they don't slow quickly enough creating minor amounts of pressure in the system between the BOV opening then closing, then pressure builds as the turbo slows, BOV opens etc etc (Can happen a few times in less than a … The flutter is caused when the throttle is shut and air caught between the free-spinning turbo and the closed throttle (when you have no vent ie blow-off valve). Page 3 of 6 - How to get turbo to flutter? Afaik if your turbo is making flutter unintentionally, it's sign of a failing bypass valve or blow-off valve. the good and bad about it, and how to get it and or get rid of it on your car Tags: None [email protected] Banned.