Robert_Cox

got a FRS was wondering if this is safe to do so??? got a couple fo mods, including filter, zorst and chip. is it safe to take the dump valev off completely or is it detrimental to the turbo??? cheers.

Lee Ivatt

iTrader: (1)

as far as im aware.having no dump valve should only become an issue when your pushing 25-30+psi.

take it of and get some chatter

gingeRS

fiesta or focus

the focus should always be run with a recirc dump valve

Robert_Cox

its a focus. ive heard that before and enquired before i put it on. soe people said they had overfueling problems and stalling and stuff like that but ive had mine on there for a good 18 months now and its caused no problems. still trying to find if its safe to run with out cos in honesty i think it sonuds a lot better

focuschivvy

turbo chatter you mean?

as far as im aware, running without a dump valve, the excess air thats produced on boost cant escape, causing it to be pushed back into the turbo, making the shaft stall , not good IMO

it does sound ace though

AlexRS2782

The Focus RS is designed to run a dump valve as standard, preferably of the recirc variety Remove the dv setup altogether & you're asking for trouble

Feel free to remove it though if you want as its your car, then you can rag the tits out of it to the redline enjoying the chatter & then you can go ahead and book your car in with an RS specialist for a brand new turbo and at the same time also hand over some more ££££ for a nice expensive engine rebuild, which is what you will need once it all goes pear shaped

I have seen it done on a couple of FRS before & although it sounds good it will ultimately be expensive for you

focuschivvy

alex, the FRS god

GUZZLER

iTrader: (3)

how will not running a dump valve affect the engine it may put more pressure on the turbo but if the car is set up properly it shouldn't be to much of a problem

COCHYN

Well if your stupid enough to run a Focus RS engine without some sort of DV, then I bet the owner will be stupid enough to not have the car setup properly

pa_sjo

The point that everyone appears to have missed is the FRS runs a MAF and not running a re-circ valve will screw up the fuelling whenever you lift, change gear, go back on the throttle..

However, as some comments above, ball bearing turbos dont suffer compressor surge (chatter) as well as journal bearing turbos so will fail considerably earlier.. Maybe even to the point of breaking shafts..

Robert_Cox

yea i totally understand the priciple of the dump valve but you see a lot of big power cossies not running them. and i obviously dont want to do it if its gonna cause ne problems. hence the reason why im posting on here to get some information of people who may know a little more than i do. it sounds good as it is, but im always looking to improve ne thing i can.

COCHYN

Just do what I did and whack a big Group A cone filter on along with either a DV26 or recirc valve. Will give you a nice chat sound. Not as obvious as the Cossie's you mention, because what your describing is an external wastegate sound.

TurboShed

When this has been raised before on the Sierra forum here, the majority of advice is it's safe for the turbo so long as it's a T34 or smaller.

foreigneRS

you may be getting confused with a blow off valve which can be used to blow off excess boost, or you are just using confusing terms

the purpose of the dump valve is to let out the compressed air that is left over in the inlet system (between compressor and throttle plate, so quite a large volume of air depending on boost pipe sizes, chargecooler size etc) after the throttle is closed and the engine is no longer swallowing it.

you are right though that if you don't have a dump valve, the only way out for the air is back past the compressor wheel. some say that makes it slow down more rapidly causing more torque on the shaft, but i don't think that it's ever been shown with shaft speed data.

i think he means if the compressor wheel is shattered and ingested

COCHYN

That's fine as it has an external wastegate, the GT series turbo's run on internal.

Robert_Cox

i got a gen 2 filter on there and a DV 26. it does sound awesome and i think thats the way ill be leaving it. im not entirely keen on running it without ne kind of pressure relief system. it was my freinds fault!! he put this idea in my head in the first place as he was running his escort cossie with out a dv. he has since fitted it as he says the car runs better with it, but it dont sound as good. its a small turbo cossie.

jammy86

The point of a re-circ DV is that the energy gone into compressing the air is recaptured rather than lost to the atmosphere. The ECU expects to see the extra air and so is set up accordingly. If the car has been re-mapped not to expect the extra air then you wont need it, however it is rare that this is the case.

As far as I know you must have a DV if running about 18psi as the inertia of the compressor starts to rip itself to peices when you get compressor stall (or chatter as some people call it).

For more advice go and ask the guys on VW fourms about the 20VT, they use a re-circ DV and all leave it in place.

As someone has said, you can remove it, but its going to be expensive.....

JAmes.

TurboShed

Nobody has mentioned that without a DV, your turbo might slow down, but you keep more pressure in the system as it's harder to escape through the spinning turbine blades than being dumped.

So, depending on a lot of factors, running no DV could be more efficient. More to the point, it sounds well 'ard

Oh, and the DV noise is