Flutter/Chatter sound. How do I get it??
 

Hi All,

As per the thread's title really!!??

Iv'e taken the HKS SSQV off and miss the sound a little! But the car feels better for it. I've always liked the subtler chatter/flutter sound but have no idea what it is or how to get it! Any ideas please?

Remove dump valve.

But depending on your turbo and induction setup ofcourse.
If you running a VF series turbo I wouldn't advise it.
And if your still using standard airbox you won't get the sound your after.

Here's mine...


Tdo5 20G, large KandN cone, front mount, maff'less

remove dump valve, cone filter, resonator delete.

thats what i've got on mine and it makes a right racket!

Sounds much better than a dump valve imo :thumb:

And if you have a fmic with hard pipes, dont that make it louder again along with the induction pipe :wonder:

My dv is on the top mount so if I took it off what do I do about the hole that it leaves

blank it off, although I would doubt your turbo wont last long.

Hmm ok might leave it then

im running a vf48 with a front mount and the hole blanked off, its running about 370bhp and has been for months now, flutters hard and had no problems what so ever

my td05's been good as gold with no DV.

Remove/bank off dump valve and fit cone filter. Beware of MAF failure issues of runinng a cone (especiallyif the bracket holding it isn't rubberised.

Probably not a clever idea on a VF turbo if you don't want it to give you issues a few years down the road. TD0s generally aren't so fussy :o

Alternatively most aftermarket DVs aren't adjusted properly or set too stiff (to prevent MAF/overrrun issues) so do it anyway :lol1:

I have a AF20g with a very little play running 370bhp was considering doing this but unsure if it will destroy the turbo or not.

What do u use to block the hole in the Intercooler as its a funny shaped hole ain't it

What year is your car mate?

2001 bug wrx

A tiny bit of play is totally normal mate

Any power gains for this mod?

About the same gains from having a dump valve.....none.....

:lol1:

but you get a bit more lag with dv less.
but im doing it as i like the sound

Wait for it!

So minimal it's not even noticeable. A decent mapper will solve any lag issues.

Im running EJ25 :norty: so should not feel the lag that much. :D

Does it require a map tweak?
sorry for highjacking your theard OP

My friend CNC'd my DV blocking off plate for me. Works very well :D

You blank it off with a plate thick enough to compress the gasket so there are no leaks.
I have aluminium plates for either Classic 99-00 Ver 5 and 6 or a different shape for new age. £10 each.

Ali-B Did you really mean to say this? :)

TD04 and TD05 series turbos are sleeve bearing and quite robust. Some but not all VF series turbos are ball race bearings. Eg VF35 is sleeve bearing and probably just as hardy as the TD series. Roller bearing turbos are probably more prone to DV delete related failures than sleeve bearing turbos because of the effect on the turbo shaft assembly. Do not try this if you run a VF22.

The dump valve is deemed necessary by the manufacturer to dump boost pressure when the throttle butterfly is closed. This relieves stress on the turbo. The turbo compressor fills the system with compressed air. When you lift off the throttle to gear change or whatever the compressed air has to find somewhere to go as it is blocked by the closed throttle flap. At this point the DV opens to release pressure.
If there is no DV then where can the air go? It reverses back up the pipe from the throttle flap to the compressor wheel and shock loads it, acting as a brake on the rotating assembly. It is this reversal you here without a DV.
The Subaru DV on all their cars is quite capable so the O/E item does not need replacing and claims that a DV improves acceleration etc are rubbish and part of dishonest glossy advertising claims to sell something that might look nice and makes a noise but is unnecessary. If the noise is important to you then that is your choice and if you want to remove the DV again your choice, your turbo but do not kid yourself into thinking it improves performance.

This.

Ive got an early HKS SSQV that does this. Was fun for a while but I took it off because I really wasnt keen on the fact it wasnt working as intended. I'm a perfectionist and it annoyed me.

Where does the air go with an OE spec dumpvalve ?

Goes back into the intake just before the turbo

And then where ?

Here's how mine used to sound, (mic was under drivers seat)
MD321T+ turbo
Custom inner wing induction kit with K&N
STI Topmount with blanking plate over dump valve hole

I asked Mark if he was still happy to warrant the turbo if I did this and he was happy as long as I didnt map in antilag