How To Get Wastegate Chatter

[Vimmy]

Not sure if this helps, or I'm probably thinking of something else, but I have both a Forge twin piston and an old Blitz single piston DV and both have adjustable springs. At the minute when I lift off the loud pedal and when using either DV I get a slight chatter from the turbo, where it is stalling, then after a short delay the DV opens and off goes the whoosh.

As i understand it, the vaccum/boost pressure on the spring holding the DV piston closed is the same when the throttle body is open. When the TB is closed there is now vacuum pressure behind the closed TB and this vacuum goes via the small piping to the spring held piston in the DV to start pulling on the spring/piston to help open it. As the boost pressure on the opposite side of the TB still exists, this then pushes on the piston to open it fully and divert the air away to atmosphere or recirculate it. As I see it the chatter I am hearing is where the spring is set too high/stiff and there is a delay whilst the boost pressure pushes on this until it finally gives in and opens. To fix this the spring tension has to be reduced or a less stiff spring put in place. However if you go too far and put too weak a spring in you will get constant boost leak as the boost pressure can force the DV piston to open, twin piston DV's do away with this problem.

The noise of the chatter is quiet loud as I have a home brew air intake thingy and the noise of the air hitting the turbo blades echoes back along to the air filter, so enclosed systems may muffle this noise due to them being sealed off within the car. I don't think too much 'chatter' is good as this does push back against the turbo could stop it rotating massively leaving you to wait a while for boost to come back as it spools back up. if the DV was blocked off altogether then all this pressure being forced background the car could lead to early turbo failure and possible consequences of the turbo breaking and parts getting sucked into the block, but I'm no expert so don't take this as gospel

I reckon the best way to get some chatter type noise out of thecar would be to have some open filter within he car so that the noise has an open exit path that can be heard or as has been said in the wing. After that then its a matter of adjusting springs or spring tension depending on the DV type.

Anyhoo just my tuppence worth

Cheers,

Col

[mctwistuk]

I love how a fairly simple question can end up with complex answers. I think that it is a no go for me at the moment. Least I know what to do to get it.

Thanks

Chris

[scoobywho]

Just get a cd and record.it onto it and just use it accordingly lol