myp1

had a prob with a dodgy bailey once..if it sounds like a horse blowing air out thru its nose then check the valve isnt stuck shut.mine was the plastic was stuck in the closed position...and this was on a calibra.open engine bay and blip throttle at idle valve shd be shut a diaphram but plastic cover open as u rev car plastic cover shd slide down and close valve cempletely.if plastic cover is stuck shut then it is faulty

[Edited by myp1 - 11/8/2003 7:38:18 AM]

mantamagic

Fitted a Bailey TP DV26 at the weekend.

Engine is more eager with excellent thottle response but there is only a chirp on gear change.

If car is standing and not in gear, when you rev the engine I get a echoey wastegate kind of chatter.

Is something wrong, or is the spring too strong in the DV ?

It's not on a scooby, it's me Astra 888. But thought you guys might help ?

Regds,

Mantamagic

Andy McCord

sounds to me that your VTA d/v is not operating at all, the chirp i think would indicate that your turbo blades are stalling, very much like you hear on a rally car

Judge

I used to run a blue spring in my forge VTA and that gave a loud tsssh when changing gear on boost but when I changed to the red spring,which is a fair bit stronger,the valve only makes a kind of chirp noise at medium revs and a chattering chirp noise at higher revs.I was told that this is to be expected so I would say that perhaps the spring is a little strong for the effect you want to achieve.

scoobylav

I am with the judge sounds like the spring is too strong to allow the DVA to dump !!!

mantamagic

On speaking to a Bruce at Bailey, it is fitted with a strong spring.

Something to do with the maf on the Astra.

The valve has to shut quickly so not to upset fuelling.

Echoey wastegate noise is just the wastegate closing noise being heard through the cone filter.

It would seem that dump valves do improve performance compared to the std bosch effort, as the car pull's a lot better.

Thanks for help/comments anyway guys.

Regds,

Mantamagic

Turbo_Steve

The wastegate is in the exhaust pipe? Why would you hear it from the air intake? It doesn't really 'chatter' either, it's just open a varying amount, or closed. I think your turbo blades are stalling.

scoobylav

Exactly how bad is it when turbo blades stall ?

Andy McCord

it will disintegrate very quickly

scoobylav

If you are correct in the noise being the turbo stalling then mine has been doing it ever since I have had my scoob. If this is so how can you prevent the turbo blades stalling ?

Judge

I have had this noise for over a year and my turbo is still going strong.Would suggest that it is not stalling but is the strong spring in the DV.If my turbo should blow up tomorrow I will,of course,apologise.

Turbo_Steve

It depends on the type of turbo you have as to how bad this is, and how much stall.

This isn't gospel, but I would imagine a TD05 with a slight amount of stall is going to last a lot longer than a VF12 with no dumpvalve.

RB5_245

Depends on the turbo you have, ie the sleeve bearing TD-- turbo's will handle stalling a lot better than a roller bearing turbo. If you want to run with a chattering wastegate a 360 degree thrust bearing is the way to go.

I had originally thought that the chattering was from the blower side blades stalling (turbo surging) but after a de-cat the noise is louder therefor i'd say it is the wastegate.

Surging sounds like an asthmatic blowing as hard as possible down a drainpipe.

Dave

scoobylav

I always thought it was the wastegate too, not the turbo stalling

Turbo_Steve

My turbo has ALWAYS sounded like an asthmatic blowing down a drainpipe.

r

i am an asthmatic!.............never thought of blowing down a drain pipe,any good?

RB5_245

r.... please blow hard down a drain pipe and record the noise to help educate others...

Drainpipe blowing at full throttle is just induction noise, it's when backing off you hear the turbo surging.