stg1 saff std turbo

 

I would say yes, if Ford put one on then it is there for a reason

 

It depends on if you have at atmospheric one, or recirculating (the latter is the standard)? But yes, agreed it should have one of some sort.

Martin

 

I took mine off and fitted a group a air filter to get the chatter but I'm not sure it does the turbo any good? Few turbo places have told me on the t series turbos it doesn't matter but I'm not 100% sure

 

It doesn't, look at the physics, without a DV the boost has nowhere to go when the throttle closes, so it is forced backwards through the turbo, trying to turn the impeller, which is spinning extremely fast in the opposite direction (this is the 'chatter' you hear, and has been known to break the blades).

A DV, opens and safety releases this pressure, preventing this from happening.

Martin

 

i think its a good idea io keep it i thinks ray was lesley7

 

This is the ultimate can of worms. Has been done to death over multiple forums and you will never find an conclusive answer for or against.

As Marty explained it would seem that the compressed air passing back through the turbo could cause extra wear. However, you'll only ever read about this and the potential damage it can cause from the people who make and sell DV's.

The other side of the argument is the ammount of people (myself included) that have run turbocharged engines with no dump valves for years without issue. I ran my t3 at 17psi for 40,000 miles over 5 years without a dumpvalve without issue.

Then there is the argument that some cars didnt run them from factory, but then most people modify their cars and are running more boost than the factory so thats a grey area...
Some people say new cars run recircs to prevent damage, but others argue this is to keep various boost related engine noises down for a more refined drive.

Some people say if you have a ceramic turbo you HAVE to run a DV, but many people haven't without issue.
Some say you can run a ballbearing turbo without but not a journal bearing.. again people have and havent without issue.

On top of all of this, it's an engine component, they wear out, sometimes other factors can contribute to them not lasting as long. (cheap oil, not warmed up/cooled down correctly, not serviced etc..) So the results can vary massively from person to person, car to car.

However, it's the sort of thing where if you are worried about it, running a dump valve will not do any damage so it's a safe bet. I personally run a recirc valve on my new zetec turbo, but mainly because as cool as chatter is, it can get very annoying if you do alot of driving.

 

would i be wright in saying that the atmospheric releases out to the atmosphere and the recirc one blows back through the charge cooler i thought i read in fast ford that they blow back and keep the turbo spun up but from what im reading its blowing back in the oposite direction do both make the same noise my thinking of running withought was i got a less chance of having boost leake through the waste gate mine is on top of the std 2wd charge cooler

 

That little company called ford thought it was a good idea along with the engine gurus cosworth.

I would fit one.

 

Yeah atmospheric just releases it under the bonnet. Recirc will take it from the intake and return it to just after the airfilter and is usually a much quieter operation.

The argument goes that releasing the pressure from the intake through a dump valve / recirc will allow the turbo to spin freely and mean less lag between gear changes as its already spinning. However, the other side to that argument is you have dumped all the pressure out of the intake and the turbo will need to repressurize it again.

 

They reduce stress and forces on the turbo.
This maybe a little benefit on lower stressed applications or a greater benefit on more highly stressed applications with respect to turbo life.

All the other talk is white noise.

 

did you sort your water prob

 

I bought a higher pressure cap from Pro Alloy I think it was, not run the car since and won't really know till I do a track day later in the year.