what to you think about d/v's

 

How will it make your car 35% faster????????????????????

 

good makes your car 35%faster??

hell yeah if not even 50%

 

im saying thay are crap!!!chavs probly say it does.

 

it just shows that your retarded if you vote yes!!

 

Dump valves are needed on some cars running big turbos so they are not crap

 

well ok but e.g on a rs turbo or cossie:

big power norwiegan cossies do not have dump valves they have big,big wastegates=cossie's,rs turbos etc.dont really need them.and i dont like the noise of them

 

ok

 

 

But come on an extra 100bhp right across the rev range cant be argued with

 

 

 

my dump valve fell of yesterday(lost)so i now hate them

 

have you noticed the 35% loss in power now then?

 

A dumpvalve made quite a difference to my XR4x4 turbo. Didn't make it faster as such but when you came off the throttle without it it was like the engine was hitting a brick wall.

I think it may have been down to it having the K-Jet mechanical metering head but I aren't sure.

 

Depends on the application. You can't really make a sweeping statement and say they are crap.

On an RST or Webber managed Cossie then no they aren't required until 30psi of boost has been reached or the turbo is T4 or larger

On a EEC IV equipped Cossie then yes they are needed as the air flow sensor can't work out which way the air is being passed over it and gets upset. Focus RS also require them as the turbo in use a bit more fragile and suceptable to damage through compressor stall.

At least that is my understanding of things

 

See my sig for details

 

Some engines will lunch themselves almost immediately without one, and some forms of management require one be fitted too for correct operation.

 

That's fair, but at least get a silent one

 

I've got a Forge Motorsport one for my car, not because i particularly want the sound - but because i'm only building this car once...

Don't particularly like the concept of paying three/four figure bills in comparison to spending Ł60 and having to put up with the dump valve noise

 

Is that for the S2 or something else?

 

who gives two fucks whether anyone thinks theyre good or bad ? just about everyone had them until someone on here decided it wasnt fashionable any more

i like mine and i like the sound of it, if you dont like them take it off, or in your case dont fasten the clip up and let it fall off

each to their own

 

Now that's funny

 

i dont believe they doo fook all
or even this bollocks there good for ur turbo by and others say there bad for ur turbo
i like the sound of it and love it wen i come on full boost and get dumpy and shudder i think its all down to personal taste

 

This has come up so many times and theres been so many debates, bottom line is if you dont like it dont have it simple

 

Man my S1 is wikid wiv a dump valv guy........I is flexin' wiv one ma car and da chiks dig it ya no ?



FFS - another one who hasn't got a clue telling us all the facts of life when he really should do research before posting

 

I can't stand the noise TBH, but have reverted to putting one back on my Cossie as I ran it without one for about 6-7k miles and the turbo was absolutely fooked in that time from being recon'd.

Only got the std one on the FRS but its bloody loud now since putting a K&N on it, cant win.

 

Most turbo cars have them as standard but are recirculating ones which is far better. No noise and prolongs the life of the compressor when running increased boost.

 

My Focus has a recirc one on (std) and with a K&N cone its loud as fuck! Not what I expected or wanted.

 

they sound terrible!!!
but u need them most of the time if your going big BHP.
try a re-circulating one

 

well im sure theyre there for a reason not just a ptschhhhh



personally dont like the sound of them the Cossie's never had one, prefer wastegate chatter it sounds less ghey

Sarah

 

Wastegates don't make any noise. I wish people would stop calling it wastegate chatter. It's just chatter

 

Thats logic for you. Lets have a look at why the dumpvalve was invented shall we? And no, it wasn't to make your car go "P-TISH" either....

The idea behind a dumpvalve is to release trapped air from the intake system - between the turbine housing and throttle butterfly - when the throttle is snapped shut (eg, lift off or gearchange). Think of it like this : you have pressuried air from the compressor housing being fed to the throttle butterfly to enter the engine. When you snap the throttle shut this charge air has nowhere to go. It crashes into the now shuit throttle butterfly and richochets backwards, towards the compresser of the turbo. This is it's only exit point - throught the compressor wheel and out via the air filter. The process caused by charge air travelling backwards through the compressor wheel is called "turbo stall". It can significantly slow the speed of the turbine, and in some cases (if there is enough air) stall it. Meaning two things : 1) when you get back on the gas again you have to speed the turbo up again and start compressing all over again - this is called LAG. 2) turbo stall can significantly lower the life of the common shaft and bearings inside the turbo - in extreme cases this is called FUCKED.

So, the dumpvalve opens when your throttle is closed (dumpvalve is kept closed when the throttle is open as it is under vacuum(sp)) and releases the trapped charge air so that it doesn't travel backwards through the turbo calling turbo stall, lag and lowering the lifespan of the componants.

Don't like the noise, or attribute "nah they're shit cos of the way they sound" ??? Then get a recirculating dumpvalve - the type that is fitted to MANY cars from STANDARD (including RS Cosworths )

Oh and whats the point about the big BHP cossies having big BIG wastegates? So what? All the wastegate is, is a part of the turbo that opens when the turbo has achieved the preset ammount of pressurisation (ie, if the turbo is set up to make 25psi, the wastegate opens at 25psi) to allow a flow-out of exhaust gas (from the exhaust side, not the compressor side) from the turbo to maintain a constant 25psi held, rather than to carry on building pressure. The wastegate does nothing like what a dumpvalve does, and it DOESN'T contribute to any chatter noises either.

Chatter noise is the sound of charge air being "chopped" by the compressor blades as it exits bacwards through the compressor and out the air filter when you don't have a dumpvalve

 

stop trying to be clever

if i just said " its got chatter" people would look at me like i was a stupid bint ,if i say wastegate chatter it sounds interesting

Sarah

 

Just say "it's got XXXbhp, now fook off "

 

cheeky bugger

just cos you drive a scrap car doesnt mean your better than me

Sarah

 

You are a tool

Your dumpvalve fell off, and for that reason you hate them? Shouldn't hate yourself for being such a tool you can't secure one to your car properly?

On a side note, did it fall off while you were driving? How did you get the car home again, as you would have had a major air leak without the dumpvalve in it's place and the engine wouldn't run

 

2 scrap cars

And I did mean when you're telling people this :

Just tell them it's got 350 or whatever horny stallions under the bonnet, that ought to concern them more than does it go 'ppsssssssccccch' or not

 

Unfortunately, you achieved the opposite of your objective , no need to talk rocket science if you are not a rocket scientist is there

Thrush: top explanation

 

I try!

Just annoys me when youngsters who have no clue what they are actually talking about come on giving it all like they DO know what they are talking about