The Gravedigger

That's what I got asked today, while discussing proposed Stage 3 upgrade for my 4b Sapphire...

He did go on about lag etc. but my eyes started to glaze over...

The proposal is: exhaust, 3-bar map sensor, -31 actuator, Ahmed chip, cone filter, looking for 330 bhp.

nikh667

Seems to be a hot topic of late - see https://passionford.com/forum/viewtopic.php?t=74261 for more info and advice.

foreigneRS

i run without a d/v. i find the engine more responsive, with no more lag on gear changes. i run without to eliminate problems that can arise when the d/v leaks.

ScoTTyBEEE

I run with both and get a dump valve WOOOSH AND chatter, best of both worlds (or something broken!!!).

wimwerf

me to....

JBcos

i did run a dumpvlave and notice no difference except noise now that i only have a cone filter.

Cone filter sounds much better imo

wimwerf

noise of sucking air

The Gravedigger

Thanks for the link, so far the the chatter is ahead...

nikh667

No probs - am running a dump valve and cone filter on my Stg.3 4x4 Saff - get the whoosh at low boost but good strong chop of air back through turbo when foot down. Not really thought of trying it without DV - may give it a go but seems to run just fine as it is. Worth knowing from various posts and opinions on her that it appears no more detrimental to the turbo to run the car without....

JamesH

iTrader: (21)

CHATTER

deleted

no dump valve on mine prefer the chatter

mattbibs

chatter does sound the bollocks on cossies!

seveneigths

there is no sound like stag 3 chatter,it reminds me of the old rally cars,my 4b has a cone filter from quick shift racing and a polished pipe the sound is awesome

churchy

I've found a better response without a d/v on spin up, and the chatter does sound better, but at the cost of your turbo's length of life.

rapidcossie

after spending a fortune on hybrid i'll keep the dump valve cheers
both sound good but you will get bored of either.

mattbibs

you have to run some serious amounts of boost for the turbo's life to be shortened by chatter!

salmon

Whats that squeking noise you hear on rally cars out of interest?? (Malcolm Wilson old Michelin Pilot escort used to do it really loud).

tont2002

wastegate noise (i think)

The Gravedigger

I'm planning 350bhp shortly via a hybrid, is chatter gonna damage my new turbo? And in general, why do they get damaged by this?

cossiedaz

i prefer the loud crack of a dumpvalve, specially wen drivin in built up areas as u dont have to go fast and everyone looks.
anuva reason is i get ppl thinkin my car is fake cos of not havin a vented bonnett (pre-90 2wd) so its easier for me to convince them otherwise wiv a dump valve

puntoturbo

wastegate noise on rally cars is because of their external gate

mattbibs

the damage is caused by the compressed air being forced back through the compressor housing. this causes the chatter or fluttering sound as the blades are still spinning after delivering the boost. the bigger the boost pressure - the bigger the potential damage.

it not so much about the bhp figure its more what boost pressure you will be using. think i read the other day that a sustained 24 psi tends to blow up these T3's!

Simmo

iTrader: (20)

I didn't have a dump valve when i bought my 2wd stage 3 saph and loved the chatter, but put dump valve on to protect turbo. noticed it picked up better on gear changes... fresh cool air must make a small difference. have now been told you don't really need dumpy unless you're running monster T4!

Cos500

Are dumpvalves somehow now available for diesels, had the 500 out last weekend and im sure the tit that pulled up next to me in his diesel rover had something like that on it, i had to laugh specially when he stalled it after reving it as much as he could so i could here the noise. very sad.

mattbibs

yeah but apparently it costs like Ł300 to put a DV on one of those!

and as said before they serve no real purpose unless running monster power!

Richors

Don't differnt types of DV's make different sounds then?
I tohught group A ones chattered and ones like Baileys and Forge create the whoosh noise.......?

The Gravedigger

Actually I quite like the sound of "monster T4"

dark3drcos.kickass

chatter every time it sounds fucking awesome dump valves sound gay and should only be used on fiats and renos. i had one when i got my car and it made both in relation to earlier posts but out the dv went first poss opp

The Gravedigger

LoL I like that

3dr_Mark

mine has chatter and no dump valve

chatter has always sounded more like a rally car to me and sounds great on cossies

dump valves are for people who want to be noteced around town

Hectori

Dump valve protects my turbo, and works much better whit it. who cares what it sounds like, when its better than whitout DV.

dark3drcos.kickass

still stick with earlier statement (dump valves sound gay) and gayness should be avoided at all costs

Stavros

Chatter, which is what we talking about, its the noise of the air coming back out the turbo inlet when the throttle shuts.

absolutley nothing to do with the wastegate in the slightest, whoever started that famous rumour needs a slap

its got absolutley fuck all to do with wastegates, external or not external

Hectori

i rather have DV and hi boost and sound like gay, than have chatter and let everyone know you dont have power in your engine.

i think that all show, no go shit should be avoided at all costs.

all Cosworths should be build by race spec, not race looks.

dark3drcos.kickass

but race cars don't run hi boost they rely on quality of engine build so if you run hi boost your car bears no resemblance to race car as a wrc car is limited to little over 300 horse

Hectori

WRC cars start from high boost at low RPMs and then begin to tail off into lower pressure as the revs build up. so actualy they run at hi boost. and there are many race cars that dont have restrictors, in other classes. rallycross for example.

and i know you just didn`t compare your cossie to the WRC spec car. WRC cars are custom build all around.

dark3drcos.kickass

it seems it isn't just dump valves that sound gay and i quote " i know you just didn't " i wasn't comparing my car to anything as it happens, it's obviously a case of agreeing to disagree i suppose, in my opinion my point is valid in yours not so it seems

DAN P

iTrader: (1)

my stg 3 cossie sounds the nuts no d/v in sight CHATTERR baby


DAN

MADsteveCOS

Wastegate chatter, without a doubt, it drives women crazy!!!!!!!!!

JimRS

Dumpvalves are really useful when ur running high boost on a high BHP engine. Some people say the wastegate chatter on a High performace engine can damage the turbo.