Just wondering if its possible to get turbo chatter with a scooby if you remove the standard recirc?

 

Yup.
Although you might want to be careful - the MHI turbo's (TD04/05)don't mind this, the IHIs (the VF ones) do.

 

Why dont the VF series turbo like wastegate chatter ?

 

is turbo chatter the same as wastegate flutter ? why is it ok on one car and not ok on another ? does the subaru wrc have a dump valve fitted ?cheers nomad

[Edited by nomad - 7/7/2003 11:34:03 PM]

 

The VF models are roller bearing, spin more freely, don't like spinning too fast. Yes WRC cars use dump valves

 

Turbo chatter is the compressor, etc. stalling. And it can destroy some turbos while not affecting others that much as noted above - it depends on the bearing type. Some bearing types are tougher than others - MHI uses sleeve bearings, which are very tough. IHI typically use roller bearings, which are more 'free running' (help spool up earlier, for example) but are far more delicate.

 

Cheers nom for explaining why it should be TURBO chatter/flutter and not WASTEGATE chatter/flutter, you wouldnt beleive the arguments i've had with people about how its the blades chopping up the air as its coming back through rather than the wastegate bouncing open and closed! I Know people who run T34's on cossies who run 28-32 psi without a d/v and they have no problems at all with reliability just wondering if scoobs followed suit.

Which models have the stronger bearing type turbo as standard then or are we talking aftermarket hybrids? dont know how to translate all these jap spec turbos its easier with the ford/garrett stuff!
Cheers

 

I tried to get my my99 to "chatter" last night by disconnecting the vacuum line to the dump valve (it's a forge recirc with red spring + 3 shims - ie unbelievably difficult to push open). It's got a tdo4 turbo running 18psi boost. No chatter though just a bit of surging on lifting off (sort of WHEW-ew type of noise). I reckon you need to be running a lot of boost to get the WRC type noise, plus it depends on the configuration of the compressor blades. It certainly didn't increase the lag between changes also.

Simon

 

The MY99/00 has the TD04, which should chatter... I certainly have managed it in the past when forgetting to reconnect the DV hose but then I was running a different air inlet system on top of the induction kit. You do need something that lets the noise out - like an induction kit, etc. It should also do this on normal boost (just!) although nothing like to the same extent as the WRC stuff, no

 

Mine cahtters when i disconnect the d/v, standard internals. Nightmare for MAF sensors though, it f***** mine in a week, with the backpulse through the air filter i reckon, TD04 at the time.

 

can anybody specifically tell me what needs to be done and required to get a chatter from td04 turbo

cheers

 

simply remove the dump valve and block the pipes..

I did this on my 350bhp engine with td05.. dont know about reliability though.. its not a word Ive ever really understood...

David

 

I have seen it on here quite a few times before that WRC cars do not use dump valves but are mapped for anti-lag.