hi all,is their anyone out there who can help me.I have an 03 sti uk and have just fitted a cold air induction kit that reaches down into the wing and just sits nicely behind the fog light cover. I seem to be able to hear the turbo spool up alot more and more alarmingly i am getting a kind of fluttery sound at higher speeds.will this be hurting my car in any way,can anyone shed any light on this problem,thanks in advance for any help.

 

Air coming back through the turbo and being chopped by the blades.

 

"flutter" noise reported by many excited enthusiasts may sound good but is actually very unhealthy for the turbo. The "flutter" occurs when upon shutting the throttle, air caught between the free-spinning turbo and the shut throttle. The consequent back pressure forces the air back through the turbine blades. This process, more commonly called "cavitation" places enormous loads on the turbo and can lead to premature wear of the turbo bearings and other load-bearing components. The cavitation or "flutter" can be fixed by either fitting a blow-off valve onto a system that hasn't got one, or making sure the blow-off valve is matched to the output of the turbo and is not working outside its flow capacity and ensuring the blow-off valve is set up correctly."

 

Normally caused by an aftermarket dumpvalve thats been incorrectly adjusted. Its shouldn't happen with the factory item, unless its broken.

Not good for VF turbos, but the TD05/04s can handle it.

 

my 52 bug flutters in 4th 5th and 6th under acceleration
and not when throttle is lifted

mines fitted with k&n type induction kit and a bailey dumper

alls fine in other gears when pressing the loud pedal

any ideas??

 

hey thanks for the quick responce,i think ill put the standard air box back on just to be safe.

 

i dont mind getting hands on with my scooby but hav'nt got the technical knowledge on somthing this complicated.

 

hey nice buggy by the way

 

After fitting a freeflowing filter (in the airbox) and removing the snorkel (air box resonator) I got the exact sound you are experiencing.

This sound is more noticeable under hard acceleration in 5th and 6th gears, I quite like the sound btw.

I too was a little concerned and posted the same question as you have asked. After a couple of replies from people that wasn't particularly sure what they were on about, Andy F responded and reassured me that all was fine, it was just the sound of the turbo being more audible with the mods mentioned.
The sound was originally there although alot more suppressed.

Nothing to worry about.

 

Yup, nothing to worry about. Sounds good

 

I get a fluttering sound when accelerating from too low a gear ie as the boost builds. Fluttering then turns to a whistle as the induction kit comes on stream. All sounds rather nice to me

TX.

 

Sounds even better with no dump valve at all

 

in my classic since having the decat fitted, i get the fluttery noise too, but lower down in gears when accelerating softly.

withour trying to disprespect satans baby, il go with what andy f says, over someone with lexus lights. again no insult intended so please dont take it the wrong way

 

is there a way to get my classic to make this 'flutter' sound and not bugger the turbo as i quite the sound also

would be quite interested to know

 

I have a decat and mine also flutters a bit under scceleration (more noticible when accelerating while low down the revs) Sounds like I can stop worrying about it then -PHEW-

 

mine flutter heavily, with a vf34, decat, induction kit, autronics o and a front mount.

its nothing to worry about, and sounds seriously cool

 

hello mate, just a quickie about your de cat blitz - did you notice any increase in power after you fitted it? I've got a full system (Magnex), but need to get the cats taken out, just wondering if it's worth it? I've been told you can expect gains of 20 - 30bhp, is this true, or just sales banter??

 

yes you will get gains from decatting alone, and 20-30bhp is about right, you'll get an even greater increase 40-60bhp with a remap as well

 

aye. il hazard a guess ive gained around 25-30bhp from decatting without supporting mods. got a decent air filter too, so the above guess would seem closeish...

andy

 

Put my DV in the bin for the sound!!!

 

Would the wastegate be causing the flutter noise?

 

Ever thought of joining the diplomatic service?

DNC

 

nope, although its commonly known as wastegate flutter

 

love the noise, large turbo and adjustable dump valve that doesnt vent till 0.5bar. LOL

 

why thankyou

 

thanks to all for the advice,you have put my mind at rest, (again).

 

i want my impreza to chatter/flutter

iv got hks ind kit + full straight thru pipe...am i going to have to bin my hks ssqv????

 

I got the flutter sound since fitting FMIC and cold air induction in the wing. The noise is turbo surge. It's not supposed to be good for the turbo, but loads of people run with it and there don't seem to be that many blown turbo's. If your turbo dies - fit a bigger one

 

^^ Bob Rawle heard mine & didn't say it was a problem ...

TX.

 

had the same for 33k now all still running good got a very big k&n on the car

see view my scooby