fiveskin

hello all.

I get an annoying flutter at low RPM, only under load and it disappears as you speed up. It also stays to the pulse of the exhaust. Its only on acceleration not lift-off, and its definately from the downpipe/turbo area as i can hear it very concentrated since the bung was cut for my gauges in the footwell.


wastegate flutter seems to be the yanks opinion of it...

it sounds EXACTLY like this video of someone with the same problem. some say shortening the wastegate arm (surely this will cause spiking though?) and some say wrapping downpipe can hide it...

i had new gaskets when the downpipe was fitted, no leaks anywhere as i asked subaru to look during some warranty work and also two other places have had a look and could find no leaks.

opinions? anyone else get this? dont seem to have any performance problems, just swear its getting louder...though i think thats my imagination where its just annoying me.


2006 wrx flutter

bengo

iTrader: (17)

I have the exact same noise on mine since fitting my decat downpipe (which is heat wrapped). I'll be mapping it later this week once my Tactrix arrives so will be adjusting the actuator and WGDC maps. Will keep you posted...

fiveskin

Mine was fitted and mapped same time.... There has always been a slight tick even when fully standard but downpipe being more open and thinner seems to have increased it.
It seems a case of some do it some don't from what I've read on the yanky forums.

It's just really annoying when say you're going up a slow climb in a built up area. Say doing 30 in fourth half throttle, the sound reflects off buildings around you. Actually feel embarrassed by it sometimes.

stort

I had this problem with mine a little while ago and thought it was something to do with the exhaust on it. It wasnt!

Try shortening the length of the actuator rod (only do half turns at a time though). This will also increase the boost so make sure you dont go over doing it or you risk your engine.

I gave my one a few turns and the noise went. The car also goes like stink now.

fiveskin

did see someone had done that on a yanky forum, did you have any trouble with it spiking after? Didnt wanna touch when first i read it in case adjusting it meant my map would need going over again.
How many turns did yours take til it went? And was it totally gone or just loads quieter?

saiklon

There is no such thing as wastegate flutter, there is however a phenomenon called compressor surge.

The video you posted is (most likely, can't stream video at work but 99% of youtube videos are of this) of someone lifting off and getting compressor surge because of a stiff/or no BOV.

The one you are getting during acceleration seems like it's caused by running the compressor in the surge region. It can be cured by a remap of the ECU to reduce the wastegate duty during spool-up. Does your boost fluctuate while you are hearing this sound?

JohnD

iTrader: (5)

Yes, the symptoms tend to suggest compressor surge.

JohnD

Big 'D'

Do you have an aftermarket silicone turbo intake pipe fitted?

stort

It only took a couple of turns to get rid of it but I thought I would go with a couple more.
I wouldnt recommend doing this many without checking every half turn though.
Apparently you can cause underfuelling to happen if you over do it though and the ECU would need to be remapped.
Give it a go and if it doesnt work, just reset it back again.

maydew

iTrader: (9)

does this happen around 0.5 bar boost??

believe its because there is no cat and flow is less restrictive/less back pressure so noise is more pronounced.

quick and easy to test if its the actuator making the noise,

remove the pipe going to the round gold actuator part
either block pipe or bend pipe and cable tie it.
drive it to 0.5 bar boost and ticking noise will have gone if still there check heat shields etc

.... at all times keep eye on gauge dont let boost build over 0.8 as it will keep building boost.....

td04 actuators are on the weak side and start opening a little premature then close again so its very slighty flappin hence the noise is only there on light boost
turning the arm 2 1/2 turns wont do no harm

sti_scott

I also have this noise sounds like a whistle

53

iTrader: (41)

That would really annoy me, even if it isn't, it sounds like a phutting uppipe which is really annoying !

fiveskin

Big d - standard turbo pipe still.

Maydew- gonna try your idea tomorrow if I get time and double check.
I've not noticed the boost bounce around, not long fitted a gauge and since the I've not had any clear runs only crap work and back traffic driving. Another thing to check the weekend.
I'm definitely not hearing a whistle of any kind though.

It starts ticking faintly at -5 or -7 psi roughly. Then it gets louder and quicker along with the exhaust pulse up to around 5 psi if your really giving it some, and about 8 if your not. Most audible high gear low revs. So if say you were plodding up a hill that's a 3rd, sticking it in 4th very low revs and foot flat down you hear it. I'm seeing Duncan/dynamix soon for a map check over and some other bits so hopefully all ail become clear.
Definitely zero noise on lift off though.

It's fitting the gauges and having the bung out that's really made me hear it

dynamix

iTrader: (3)

Sounds like the boost solenoid doing its job in controlling boost after a decat to try and keep it under control.

Easy enough to datalog and identify it for you though

mikescooby

iTrader: (2)

thats loud. mine aint has loud as that

fiveskin

Can't tell how loud mine is outside , but sounds louder with the windows shut as it's being concentrated through the bung hole (ooh err)

And cheers Duncan. That date you said was good by the way, sent you PM on .org confirming but I haven't logged back in since.
You're a bit like a magic genie on here, if someone says your name you appear hehe

sti_scott

just shortened mine by 2 full turns, it is still there but quieter may try wrapping down pipe as well.

fiveskin

doesnt the whistle noise mean a leak upipe side?

dynamix

iTrader: (3)

Not really - normally a split in the inlet pipe if it isnt just the turbo singing to you.