before i forget..
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r34 gtr
- Posts: 8909
- Joined: Sun Dec 29, 2002 9:33 am
- Car: 98 Nissan Frontier XE 4x4
95.5 Audi URS6 Avant 5spd
03 BMW 330i ZHP 6spd
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before i forget..
my turbo is making a funky noise. If anyone watched that advan neova drift video, you might have noticed how those cars all made wierd sounds when they shifted gears or let of the gas in any way. my turbo makes the same sound. the reason im asking is that it didnt make this noise before, but my turbo was raped to hell, so i can see why it wouldnt have. is this normal or is my actuator being gay and not working? ive got plenty of time to worry about it because of my water pump eating problem. thanks! - tim
ok i assume your talking about the few cars that have the fluttery type of sound when blowing off. i can make the sound with my mouth but not on the keyboard ! that is noise from wither rerouting or not having a BOV installed ! ! least thats how mine sounded till i started venting it to the open air !
that fluttering noise is compressor surge and can cause damage to your turbo. the reason that it may be occuring are:a) your stock bypass valve is stuck shut and no longer is recurculating the air. when you shift gears or otherwise let off the throttle at high boost the pressure, the built up pressure in the intercooler piping hits the throttlebody and bounces off. with no place to escape to (since the bov is closed), the air slams back into the compressor wheel and back out the intake itself making that fluttering noise. this not only is bad for the turbo but significantly slows down the wheels so you need to spool the turbo again.b) same situation as before but your bov works, its just not flowing enough air to let out enough pressure. this normally happens if you run high boost on the stock bov.c) you dont have a bov installed on your car.
when i got my engine swap my mechanic hooked up my bov wrong so it wasnt opening at all, since he had the pressure line connected to the compressor housing not the intake manifold so the bov was always seeing positive pressure. i thought the compressor surge was actually the bov sound and ran the turbo at too high boost and physically blew half the gasket between exhaust manifold and the turbo off the car, and pretty much ruined my stock turbo in the process.
when i got my engine swap my mechanic hooked up my bov wrong so it wasnt opening at all, since he had the pressure line connected to the compressor housing not the intake manifold so the bov was always seeing positive pressure. i thought the compressor surge was actually the bov sound and ran the turbo at too high boost and physically blew half the gasket between exhaust manifold and the turbo off the car, and pretty much ruined my stock turbo in the process.