Marts

iTrader: (1)

As title says, does it?

Reason i ask is i just got hold of a solid boost hose (hard pipe), but it doesnt have the D/V outlet pipe on it. I am using a D/V at the minute, but will have to lose it when fitting this new pipe...unless i modify the new pipe.

My Series 2 has a pretty good Spec i.e Chipped, cammed, larger intercooler blah blah blah, but do i still need a dump valve or can i get away without using one?

Any help would be helpful, thanks

Chris69

you don't need one mate, the garrett T turbos cope fine without them

Marts

iTrader: (1)

Plus it removes one possible future air leak innit.

Is there ever a stage where the Series 2 needs a dump valve tho? Like when its running stupid boost pressure?

Chip

iTrader: (3)

Turbo life is generally longer with a DV than without, especially if you run the turbo to very high RPM's

Not needed as such a T3 but it will last longer with one than without.

Christian and Beccy

iTrader: (14)

I don't run a DV and never have. Last time the car was on the road, it was running 30psi with a GT30.

I have a Tial BOV here ready to fit with the new spec, but still not sure whether or not to bother. So generally speaking, I wouldn't fit one to an RST.

Marts

iTrader: (1)

Ok thanks guys The life shortening of the turbo is nothing too severe tho is it? I only had the T3 refurbed a short time ago, so surely that will allow it to last longer (hopefully)

Kinda feel safe in the knowledge that Christian ran 30psi without one lol

Without it, will the MFi give off that 'flutter' sound?

cozmeister

iTrader: (1)

It's not gonna cut its life expectancy in half, if that's what you want to know, but be aware that you will need to start saving the $$$ earlier.

Stu @ M Developments

iTrader: (12)

Sometimes you just need to ask yourself, did Ford fit one?

If they did, why did they? If they didnt, why didnt they?

Christian and Beccy

iTrader: (14)

Fair point, but raising the boost/performance can in some cases alter the answer to those questions. Although in this case, my personal opinion is that it isn't needed.

pa_sjo

Stu, that'd be far too logical. Waiting until what you want to hear on forums is much better.

Stu @ M Developments

iTrader: (12)

It does indeed sometimes, no argument, but in this case, in my opinion, the only thing that would really alter the answer to this question would be removing the Bosch KE system as thats the main reason.

Bosch KE fitted by Ford on 8psi engine = No Dumper.

Weber Marelli fitted by Ford on 8psi engine = Dumper.

Thats should tell you a lot.

Marts

iTrader: (1)

So Stu, what ya saying is, no it doesnt need one - in your opinion?

No, Ford never fitted one. Reason: At standard spec, there is no need.
But... Did Ford fit modified chips, uprated cams and larger spec'd actuators etc? No...

So the answer could well be on the toss of a coin!

MarkXr

What Stu is trying to say is that the KE Jetronic (MFI) doesn't operate very well with a dump valve fitted. Reason is the system measures the amount of air flow passing the metering head. Creating a leak in any way between the metering head and engine causes mixture issues.

In other words, don't fit one when running on MFI, do as you please when converted to EFI.

(must say that I'm running MFI but still have a dumpvalve. It's possible but far from ideal!)

Turbocabbie

I think what Stu clarified is that Ford considered it necessary to place a dump valve on vehicles using Weber Marelli management (cossie) with 8 psi unlike the vehicles which ran Bosch KE (Escort) at 8 psi
Stu stated the same 8 psi boost pressure with the only difference being the management as such you can come to the conclusion that ford did not consider it a requirement based on the management rather than the boost level.

On a side note not all dump valves actually work on MFI, try a diaphragm based dump valve and you will get an erratic idle. I would never personally run any type of dump valve on a MFI based RS Turbo

Stu @ M Developments

iTrader: (12)

If 8spi boost doesnt require one, why did the Sierra and escort Cosworths both get one as standard? Its nothing to do with the turbo mate, its to do with the management.

Stu @ M Developments

iTrader: (12)

Thanks you for fully understanding what i wrote.

Marts

iTrader: (1)

Seems I have started a healthy debate - against me

So yea, you say NO to D/V's on MFi's as, and i have experienced it in the past, messes with air flow etc.

Im currently running a Bailey twin piston 'evo' and see no issues... but my old valve allowed alot of issues, mainly leaking!

As you advise Stu (being the man in the know) I will leave it off and not modify my new pipe.

Chip

iTrader: (3)

Stu, why did ford not use a recirc dumpvalve like on the cossie then?

As IME even with flow meters, they dont effect running adversely, or is mechanical different to electronic in that respect too?

Must confess I know VERY little about MFi as I jumped from carbs to EFi

Stu @ M Developments

iTrader: (12)

Dont get me wronmg, the twin pistons will often work just fine as they only allow an air leak when positive pressure is present at the input stage, and if your happy with it, keep it, but you will find that the engine runs cleaner overall without one due to the archaic design of the metering unit and the way the flap drops shut suddenly when the dumper releases pressure and you get that sudden lurch as the metering unit thinks you have turned the engine off.

Its better without, but a good one will work if twin piston.

Stu @ M Developments

iTrader: (12)

See above.

Chip

iTrader: (3)

Cheers, I guess you could get similar with flap type meters on an EFi then?

Marts

iTrader: (1)

So thats a cleaner, smoother running engine - with no noise?

I do realise EFi is a hell of a lot better than the older MFi set-up, but i didnt realise a lot thats been said in this thread. What started as a simple question has turned into a very informative read

steveyb

i second that, i looks like i will be leaving mine off too then lol

Turbocabbie

further to this discussion stu.. I have a cossie managed escort running a P8 which currently does not run a dump valve.
Considering the management would you suggest running a dump valve or does it not make a great deal of difference

jonnyrsturbo

so is that a yes or a no then lol!

might take mine off

Marts

iTrader: (1)

It doesnt read very plain and simple does it lol

Basically, and this is how i have read and understood it, with MFi, ya may aswell remove/not have one because it can mess with the air flow of the metering unit... although Twin Piston ones i.e Baileys 'EVO' valves can work adequately.

I have dug further with this today and many people say that it aint worth having one fitted due to it being a hinderence (spelling) more than an essential part. Others simply say that its better to have no sound than sound like a bus 'dumping'

Kinda guessing with this thread it aint worth it, unless ya already have one fitted with no issues, but if ya thinking of fitting one... dont bother.

Pretty much down to personal preference, I suppose.

One thing that hasnt been answered yet is what happens when the Turb dumps without a valve installed. I know the pressure goes back to the wastegate and 'stutters' the turbo fins, which inturn can lead to the dreaded word of 'Damage'... but will an MFi 'flutter' like a EFi when dumping?

If it does, the valve is definately staying off as thats a mint sound!

MorryRS

You wont get a MFI Rs Turbo to flutter as you put it. Only if you go EFI - i dare say someone will explain it fully

sm

mfi will "flutter" as much as efi, the only differnce is you will hardly hear it due to it being muffled by the metering unit where as on efi the the turbo connects directly to the air filter giving less restriction and not muffling the sound

turbozvh

ive got mfi and took the dump valve off but the sound off the turbo stall was'nt loud enough so the dump valve went back on but the car did seem to drive a bit smoother in slow traffic

Turbocabbie

Out of curiosity how many turbo's are you aware of which have failed or had damage which can be solely attributed to compressor stall and what was the boost level prior to failure.

vroooom ptssssh

What is the reason Stu?

I 'thought' it was noise suppression?