Vectra C pipe mod on Astra G!

If you mean a dump valve doesn't stop the turbine wheel shattering, can you prove that?

A recirc and atmo do exactley the same job. The difference is, manufacturers with air metres rather than MAP based fueling use a recirc to make sure that the fueling isn't compromised. That is generally only the case at idle anyway where a dump valve does nothing.

The other issue with recirc over atmo is, cheaper diaphram dump valves leak some boost. If it is a recirc it is sent back into the system anyway, so fueling stays within parameters. If it is an atmo, the extra air is lost, but the extra fuel that was metred is still injected, so you get overfueling. In a turbo car that isn't such a big performance problem as it is better to cool the piston crowns with "Some" excessive fuel, than burn a whole through them with a lean mixture. To run an atmo valve on a car with an air meter, you need to use a spring or double spring valve. They are stronger and less liable to leak boost than a diaphram. They may on occasion be excessive smoke occasionally, but nothing like a turbo diesel car.

With all due respect, i.e. none, your question was answered, or rather the flaw in your question was pointed out. A wastegate is not the same thing as a dump valve. I don't know of any "recirculating waste gate;" perhaps you can furnish an example?

Rachael (not a sock)

Let me make the question easier to understand: What possible purpose does fitting a dump valve to a road car, actually serve?

Let me make the questions simple and easier to understand.

When are you going to prove that Judge Selwood is a Mason?

When are you going to send a letter of intent to me?

When are you going to visit me to teach me a lesson?

When are you going to post the details of me which you say are on the Sex Offender's Register?

How about YOU answering some questions?

Mike That damned truth keeps on prevailing :-))

What is a recirc wastegate? It sounds to me like it blows exhaust gas back into the intake?

Then why didn't you ask that, f*ck wit? Instead of spouting some s**te about a 'recirculating wastegate'

FWIW dumping air that's already been forced in with boost, as opposed to recirculating it, helps to cool the intake charge. Air entering the turbo for the first time will be at a much lesser temperature than that which has already been through the turbo.

You're having a laugh, right?

It's EGR, 'Fast and Furious' stylee.

Model before did. And had a charge cooler. Model after did And had a charge cooler. My model didn't had a BBQ rack/Breakdown hand warmer.

"Pete M" wrote in message news:ei2neh$q7n$ snipped-for-privacy@registered.motzarella.org...

I've not had much experience in working with turbo'd motors so am unable to comment, but I've heard that the 'wastegate chatter' you speak of is indeed s**te.

Apparantly it's the noise of the air being forced back through the turbine housing, and has nothing to do with the wastegate. I did, at one point, say it was chatter but was proven wrong with an article on Wikipedia.

If anyone could dispute that and prove me right again, I'd grin :)

Do you have a dump valve fitted? And if not, if you had a turbo car, would you fit one?

No, I don't. I don't suspect a standard 330Ci would have much use for any form of boost pressure regulation.

Had I a Subaru, Evo or Cossie, yes, I would. It wouldn't, however, have a large trumpet to amplify the 'pshhhhh' noise when it dumps.

In news:xx51h.43567$ snipped-for-privacy@text.news.blueyonder.co.uk, Sandy Nuts wittered on forthwith;

TBH I don't actually know what causes the warble, but I do know that it was different when I changed the -31 actuator for one off a light aircraft - even though the max boost level was the same with the aircraft actuator the warble was brilliant....

Now we have a question............Sssuming you would fit a dump valve to a std turbo road car, what would you think fitting one would actually achieve?

Ah, the empty vessel booms out again. Ken, Kenny, Chrissie, Weekend Wendy, whatever you are, you have already betrayed your ignorance on this topic; can't you just shut up? Your statement above does not even make grammatical sense.

Modern lightweight exhaust turbine driven compressors operate close to their design limits and benefit from properly set up dump valves to avoid persistent surge conditions and early structural failure of the blades. Diesels don't suffer inlet pressure spikes the same way since they either have no throttle valve, or their throttle valve is controlled to avoid sudden closing on overrun.

Are you saying that all the car manufacturers who fit DVs (recirculating or otherwise) have wasted their time and money? I think you are confusing chavs fitting an incorrectly calibrated aftermarket DV with a "factory fitted" DV. You should read properly the posts of those you are trying to patronise/insult.

Read people's posts properly, understand what dump valves do.

Then f*ck off.

Ummmm, nearly all standard turbo road cars come with a dump valve. My WRX has one and my GTR had 2. Factory.

Fraser

Depends on the turbo. Steel compressors are a lot sturdier. My GTR had ceramic compressors. So does the Soarer and the Supra depending on where it was delivered. The Yank ones had steel. Current turbos are now even using plastic for compressor blades for quicker spool up. They reckon after one bar of boost it is goodnight Irene for them.

Fraser

Perhaps you would be good enough to denote which cars are factory fitted with dump valves?

There seem to be so many quite different benefits to be had from them, that I am sure many cars must have them as OE..................