I've just had a Blitz SUS Airfilter fitted yesterday to a MY98, and i can hear the same thing. I thought it was a normal sound. I've noticed my VTA DV is much louder too, and when accelerating the induction sounds like a touring car :)

(Also, i have a spare bracket and bolt left after having the airfilter fitted. Does anyone else?... just checking )


[Edited by Mistacain - 12/3/2002 3:53:49 PM]

Cheers Steve.......

Nope.....I'm with you on that. I don't use XS gas until she's warm.

It's just when you've built up a small amount of boost (say -5 to 0) and ease off..... Chattter away...... I can ease on and off around the 2k rpm mark a it'll chatter .....

Few..... not so worried now......

editeed to say....... coz I forgot

Maybe worth me considering the oil temp gauge..... any experience of these?? how much for one and fitting??

PS like the sound effects.......
Just have to get the story straight for the wife..... "sorry luv turbo's blown, .... need a new one....."

There's a thread on Drivetrain about a guy that gets irratic idle after he's booted it......

[Edited by Legacy4x4Turbo - 12/3/2002 6:03:12 PM]

So i've recently put a Blitz SUS Air filter on and it now makes all sorts of funny noises which is cool. One in Particular though has me guessing as to what it is?
Basically under hard acceleration i take my foot off the gas and get this machine gun type chatter? when cold it almost sounds like a second dump valve, but when it's warm off it goes. I know it not the DV as i hear this after?
anyone got any ideas ?

It just lets all the noises that were always there be heard! You're hearing either the wastegate chattering od the turbo stalling! Whatever, it would have been happening before, it's just that you can hear it now :)

If it's the turbo stalling is this a bad thing that could cause damage?

Question is: is the rest of your car standard?

If you just have th airfilter then you have nothing to worry about. The noise is natural.

However, I suspect you are either running a different dump-valve or a different level of boost. A different dump valve can definitely cause chattering noises (especially if it is a recirculatiing type, as you would not have noticed the change in sound until your new airfilter).

Increased boost will make a lot of different re-circulating dumpvalves (including the standard one) chatter.

If the dumpvalve is chattering, then the turbo IS stalling a little. Whether or not this is bad for it is something that has been debated at GREAT length elsewhere on Scoobynet. Some people do not run dump valves at all, and have not blown a turbo yet!

The only other option is wastegate chatter, though why this would happen due to an airfilter change, I don't know: possibly your car is set to prduce higher boost (dawes or ECU) and the OEM airfilter was throttling it. Now that it can breathe freely, it is boosting to target, and your wastegate is chattering.

If it is, I am jealous, becuase that sounds COOL.:D

Steve

it sounds the bollocks m8

i removed my standard factory dumpvalve and blocked the 3 pipes it attached 2 up as well as a blitz kit and the wastegate chatter is really loud now :)

Paul,

Have just fitted a HKS Super Power Flow (2 hours ago) and have got almost identical sound as you are experiencing in the same situation. My car has standard re-circ DV, Full SS inc DP/UP + Tek2.

Anyone else experienced this / know what it might be?


Tony

same hear matey, fitted a hybrid HKS Metal Flow Filter an a HKS SSQV and it chatters away like a demon....sounds wicked.
More to the point it does not sound like one of those damn granny chariot, punto turbos.

jay

I do also have a blitz DV stuck on and a scoobysport back box. I'm sure it's not coming from the DV thought as the woosh from this clearly goes from the left, where as this chatter comes from the right. Almost as if coming from the air filter itself?
Where is the wastgate located?

Wastegate is smack bang next to the turbo

I have to admit to being extremely surprised that a change in airfilter lets you hear the wastegate better: The wastegate is in the exhaust turbine side of the turbo, meaning it has absoloutely no connection to the air intake, other than a very small pipe from the actuator to the inlet manifold.

If the noise sounds "whistley" I have a horrid suspiscion this could actually be the sound of the turbine stalling and accelerating slightly as the wastegate fluctuates between open and closed. But this is entirely conjecture as I have no idea about all this. It just seems highly unlikely to me that you can hear the actual wastegate thru the airfilter, as it's only connection to that bit of pipe is thru a solid metal bar (the turbo shaft).

I am not saying anyone is wrong! Just curious?

Steve

Err no? what sort of bracket have you go left?

Please make sure your air-filter + MAF assembly is securely bolted to the chassis, or your engine will rattle your MAF to a quick death! (Believe me, you don't want this!)

Steve

I've had a HKS Ind Kit fitted since the middle of the summer (What summer) to my92 Legacy.

The noise it gives off, when you ease off the gas completely masks that of the dump valve.

However, when driving the car from cold and not pushing the car hard, I too experience the 'chatter' of the turbo.

Until the HKS was fitted, I never noticed it.

However, by the time that it's upto temp, the chatter seems to dissappear.

Running on - Uni chip, 18psi, stnd Turbo, Mongoose s/s ex HKS ind Kit - 290 bhp

I have a long "L" shaped bracket with a hope each end, and a short straight bracket with a hope each end, and one spare bolt. It does feel secure though. Just wondering if this is normal?

It goes away when warm? Hmm...lubricant effectiveness?

I am very curious as to what this noise is, now!
How much are these Blitz Airfilters, and where from, because it sounds like I may need to buy one.

go for the HKS METAL FLOW filter, same constrution as the Blitz one, but looks far better, you get the same flow and the same splendid chatter.

you will need a standard HKS fitting kit though as they do not make one for the scooby, but they fit great and look and sound a treat..

jay

may sound stupid but i have just got a scooby and when i power on my turbo heat sheild vibrates and chatters it can be heared when letting off as well as the vibration kicks in again gets worse the hotter the car gets

just an idea

i know nothing about scoobys yet

how much is a filter kit?

Turbo steve.............. don't frighten me like that when you say lubricant effectiveness........

It's only fo a mile or two. Do you think it needs looking at??

It does sound cool....... but I'd rather it be quiet andd not cost anything than chatter and go bang!!!

Mistacain
Like Steve said “Please make sure your air-filter + MAF assembly is securely bolted to the chassis, or your engine will rattle your MAF to a quick death! (Believe me, you don't want this!) “
The L shape bracket is for securing the filter to the chassis. You bolt it on the back of the air filter plate and then into one of the screw holes used when removing your air box.

Steve
Blitz air filter is about £200 most places.

DJ
Good thinking but alas I have no heat shield.

Sorry matey. Not trying to scare you.

Would like to point out, though, that if you are using your turbo when your car is cold, you probably aren't doing it any favours.

Most 'serious' turbo-charged cars come with an oil temperature guage, so you know when it is safe to put your foot down.

As a general rule (for all cars, not just turbo'd ones, really) if you go above half-way down the accelerator pedal, or 3000rpms (or so) then you really aren't doing the car any good.

I normally wait until the water-temperature needle has moved up to the "first notch", as if the water is warming up chances are the oil is way ahead of it.

Saying this, the scooby's ARE very robust, and blowing a turbo COULD be the excuse you need to rip off the pesky little VF11 and go for a TD05 or a Hybrid V28 or something! That would demand an ECU re-map, but couple it with bigger injectors and a better fuel pump and you are looking at some silly horsepower!

Rattley heatshield isn't it: I have one of those and it goes "jingle-ingle-ingle" like a sort of grasshoppery noise. Good suggestion, but definitely not the
"fffffFFFFFFTHPR-THpr-thpr" noise these guys are talking about.

Have to add that I have not heard a scooby doing it yet unless it was modified?

took my turbo heatshield off the under bonnet temp hasnt shot up so **** it hehe. As for the chatter known as wastegate chatter its the turbine stalling slightly on boost that bounces back. Sounds the tits and to be honest theres no way 12+psi of boost is getting vented through the little dumpvalve pipes anyway so its going to stall whatever. I took my dumpvalve off so i get a louder chatter.

Having said I hadn't heard it before......

Rading SiWRX..... and saying that the it can't handle the pressure return......

My HKS ind kit was fitted at the same time as a re map with a unichip.... and boost was increased along with it.....

perhaps that's why I didn't hear it before.....

Cheers

lol @ 4x4......ahhh..now the whole story comes out! lol

I agree that the pesky little standard dumpvalve cannot dump 12psi of boost, but maybe it's just to reduce it some? The theory being that if you reduce the pressure even slightly, the resistance to spin on the compressor is reduced, alowing it to spin. I don't think you actually need to dump the whole 12psi volume (especially as the turbo would take ages to spin up again!)
Saying that: I am with you on the fact that it sounds COOL and improves your throttle response to get rid of it.

As long as it will hold out (and not leak) I plan to up my boost pressure and leave it in place.

OR...I had this thought the other day about a computer controlled BOV system............................................ ....