whooshing noise Pt 2

[Oedipus Rex]

thought I\'d start my own thread instead of hijacking someone elses. When my turbos start spooling up, they are making a really pronounced noise and an even more pronounced one when they dump. I figured it must be a loose vac hose but having watched the boost pattern on my commander it seems to be building pressure fine. when I\'mm off boost it hangs somewhere around -600 mmHg.

Any ideas why I\'m getting such a noticable noise from them but still getting decent boost pressure?

[Oedipus Rex]

nobody?

[Speedworks]

Now that I have my HKS filters on I\'m distinguishing a wooshing sound when the 2nd turbo comes online.

I\'m still a lttle unsure if the second turbo makes normal pressure or if the 2nd trurbo dump valve is releasing pressure before it actually needs to -> vac problem.

[mattsteadz]

Originally posted by Speedworks
if the 2nd trurbo dump valve is releasing pressure before it actually needs to .

Unless I am mistaken (often am) there is only one Dump valve.

[Oedipus Rex]

the noise from mine starts as soon as pressure starts building

[MillSpeed]

What sort of induction have you got? There\'s several things which could be making wooshing sounds. There\'s one pipe which has something to do with the air-pump which vents when it switches on and off at around 2500rpm. It also vents when you come off the throttle. Second is the charge relief valve which\'ll start venting when the secondary turbo begins to pre-spool at about 3500rpm. Third is the dump valve which just vents boost pressure when it gets a vacuum signal from the inlet manifold (ie. when the throttle\'s closed).

[Oedipus Rex]

Originally posted by MillSpeed
What sort of induction have you got? There\'s several things which could be making wooshing sounds. There\'s one pipe which has something to do with the air-pump which vents when it switches on and off at around 2500rpm. It also vents when you come off the throttle. Second is the charge relief valve which\'ll start venting when the secondary turbo begins to pre-spool at about 3500rpm. Third is the dump valve which just vents boost pressure when it gets a vacuum signal from the inlet manifold (ie. when the throttle\'s closed).

I\'m totally stock apart from a port a downpipe and a decat (and ecu)

[MillSpeed]

Hmmm, might be something else then. The stock air box is supposed to be pretty good at silencing all the various wooshes that these cars make. They only really become audible when you put an aftermarket induction kit on it. Only other thing I can think of is a boost leak, but you say she\'s boosting fine yeah?

[Oedipus Rex]

yeah this is why it consfused the crap outta me. Getting a perfect 8 7 8 out of it. Ah screwit anyhow I\'m off to pip next monday for a new intercooler filters, ecu map and dyno. I\'m sure he\'ll hunt it down for me.

[Oedipus Rex]

:rollin


well its well and truly gone off the radar now. Whoosh has turned into a loud hiss, can;t get good pressure and when it does get up to a reasonable amount of pressure it makes a noise like a ****ing horn honking. You know, like the ones clowns hold. Also does the same when it dumps.


I\'m guessing that the dump valve hose is screwed. Still I\'ll find out on monday.

[MillSpeed]

Yeah, keep us posted dude...I for one am intrigued! I know the air pump makes some pretty unusual \'moo-ing\' sounds, but that stops spinning above about 2.5k. Hang on, when you say you were boosting 8-7-8, that\'s psi yeah, not 0.8 bar? 8-7-8 sounds a bit low, should be closer to 10-8-10 if I remember. Defo thinking boost leak now....check all the rubber pipes, the one that comes off the top of the Y-pipe is b*stard for splitting!

[Oedipus Rex]

I think something has been perishing and the more pressure I\'ve been putting it under, the more it\'s been going. Met a cooper S on the way home from work about 12.oo last night and he was dying for me to play with him so I obliged. Put it under quite a bit of pressure. Woke up this morning, got on the A1, put my foot down and it just went ppppssshhhhhhhhhhhh HONK. I was ****ing myself laughing and nearly swerved into the next lane:D

anymoo I\'ll say what it was when the doctor has examined it on monday

[Oedipus Rex]

Originally posted by MillSpeed
Yeah, keep us posted dude...I for one am intrigued! I know the air pump makes some pretty unusual \'moo-ing\' sounds, but that stops spinning above about 2.5k. Hang on, when you say you were boosting 8-7-8, that\'s psi yeah, not 0.8 bar? 8-7-8 sounds a bit low, should be closer to 10-8-10 if I remember. Defo thinking boost leak now....check all the rubber pipes, the one that comes off the top of the Y-pipe is b*stard for splitting!

0.8 0.7 0.8

I\'ve got it set conserfvatively until I get it remapped on monday. Having said that it\'s not even getting to 0.6 now.

[gavin]

any up date as to what was wrong,
im also getting the horn honking sound when 2nd turbo starts spooling and its not boosting as high as it should be,
1st turbo boosting fine until change over,
checked all hoses and checked the actuators today as well (to the best of my knowledge)

[Oedipus Rex]

yeah it was a loose clip




couldn;t be arsed hunting too hard because I knew the airbox was coming out and a new intercooler going on it hardly seemed worth the effort.