wastegate problems

[kennyrodgers84]

ok got a bailey dv30 dirt cheap and fitted it to my lcr.ever since i have done this the wastegate chatters every now and again.is this cause the bailey uses a progressive rate spring which might be a bit stiffer??before i fitted it i tried pushing the piston inside the dv up and it seems alot stiffer than the forge 007p with a yellow spring.

 

[LiCkWiD]

There is a common myth in the automotive world about so called "wastegate chatter", a noise created on lifting off the throttle in a turbocharged car. The sound is commonly described as a chipmunk or a rattlesnake and is often stated incorrectly as being a result of the turbo's wastegate closing.

The noise is in fact the air compressed by the turbo passing back through the compressor housing of the turbo after having hit the now closed throttle plate.

A blow-off valve (BOV) will usually eliminate this noise, but in some cases, i.e. where it doesn't open fast enough or is setup to only react to high boost, some chatter will remain.

The chatter noise is very noticeable on WRC Rally cars, where no BOV is allowed.

- Wikipedia on wastegate chatter/actuator flutter.

The chatter would be related to the air passing back through the housing. :S It could be caused, as you say, by a weak spring.. is it causing performance issues?

 

[kennyrodgers84]

no thats the thing,this happened last nite and the car seemed 2 pull much stronger than before.would this not tell me the spring in the bailey is too strong therefore not dumpin off as much boost as usual??

 

[DPJ]

........would this not tell me the spring in the bailey is too strong therefore not dumpin off as much boost as usual??

Vacuum should allow it to recirc so it's more likely your dv is sticking. Not good.

 

[LiCkWiD]

Well i don't mean to patronise you if you already know how dvs effect the operation of a turbo, but the idea is they purge the unused boost before it passes back through the turbo, slowing down the rotation.

When the turbo comes on boost, it forces a higher density of air into the chamber, yeh? It takes a while to generate this boost and when you ease off the throttle, the air has two choices.. without a dv, it flows back away from the throttle plate and back into the turbo. This has a reversing effect on the motion of the turbine.

Before this can happen, the dv releases the unused boost.

That said, DPJs answer is probably correct :S Can you try another dv on your tubo?

 

[RickC]

its actually the spring is too stiff, or like Dave said the pistons stuck, causing the air to not be vented and force its way back over the turbo blades,

not good.

 

[kennyrodgers84]

thanks for the replies lads.yes i do know how they work,im a mechanic but its always good to pick the brains of others who might have had the same problem.took it off there now and it does seem a bit stiff at first wen u push it then it frees up.just a bit miffed as its brand new.have my old 007p back on

 

[Mitchy]

I had same problem with the baileys DV30.

It was fine for 2 years then all of a sudden it started sticking. It would only do it for the first 5-10miles per day. When the car had warmed up, it would then work fine

Changed it for the forge valve and back to normal now

You can clean the DV30 so may be worth cleaning and regreasing it.

 

[kennyrodgers84]

yea funny enough it was at the start of journeys it gave bother.did u hear the wastegate chatter??took it apart at dinner time there and it full of this gluey ****,lol.cleaned it with brake cleaner,polished the inside with brasso and coated the piston in engine oil,seems 2 b fine now

 

[ibizacupra]

dismantle the bailey and see if the top cap is riged.. worn ripply from o ring groove

if so its dead.

had the same on mine