WREXY

If your car is standard or even slightly modified the standard item is huge enough according to MRT performance in Sydney. The aftermarket dump valve is for those that like the noise, (me included, I have the Blitz BOV), and it also does improve the throttle response I found, but no power increase. I have also heard that the standard ones can leak, so some people may change for this reason.

Cheers,

Wrexy.

[Edited by WREXY - 12/5/2001 2:05:36 PM]

Dogus

Can someone please tell me if there is any point fitting a dump valve?.... Keep hearing different opinions on the subject, some people say its just so it makes that noise, others that it protects the turbo, some say it will give more power.

Does anyone really know if there's any benefit from having one fitted?

Mickle

My standard dump valve leaks at present making a sound like someone blowing over the top of a bottle at around 4000 revs. This is the only reason I've got to upgrade to a noisier dv ;-)

Dogus

But what exactly does it do??????

WREXY

I know I'm going to make a meal out of what it does, so I'll leave it up to a techie to explain.

Wrexy.

motomc1

HI I WAS ALWAY LEED TO BELEAVE THAT A DUMP VALVE WAS TO STOP THE TURBO CHARGER FROM SLOWING DOWN.I.E STOPPING LAG AFTER A GEAR CHANGES.WHEN YOU LET YOUR FOOT ON THE PEDAL BOOST PRESURE BUILDS UP. THE BACK PRESURE THAT IS FEED BACK TO THE TURBO CHARGE THEN SLOWS IT DOWN .IF YOU DUMP THE PRESURE TO ATMOSPER THEN THE AIR FLOW STILL MOVES AND THE TURBO KEEP SPINING AT A FASTER RATE.HENCE LESS LAGE WHEN YOU PUT YOUR FOOT DOWN.THANKS MATT.IM SURE SOME ONE WILL SAY THATS BULL.

catflap

thats what i had come to beleive, from reading this forum, made a little sense as well i must say, but i read that it coul ddamage the engin on a MY99, and as such have decided to not get one, but also i got nothing but what i read on here to base that on.

Its getting a little like our suermarkets, cant eat beef coz of bsc, cant each eggs coz of salmonela, cant eat this cant eat that, wonder how many of these mods that cause damage actualy do?

But with such an expensive car(subjective, its expensive to me) i wont risk it

Craig Mac

Can anyone confirm this ?
Can a dump valve cause damage to the engine ??

Craig.

motomc1

HI ALL it could stop damage to the turbin.bye releveing the stress forses on it .engine Damage well mixture is the only thing i can think of .and thats only if you have been changeing the boost without getting the mixture to match.runnes ok on my my98 no probs
YES THEY ARE ALOT OF MONEY ....BANK LONE FOR EVER.....

simonzzr

Hi,
To answer your question on what a dumpvalve actually does,yes it will help the turbo to keep spinning to a point but the primary reason for having one fitted is to allow the system to replenish itself with new cold air when the hot air is Dumped.
Cold air is dense air,dense air means more fuel,more fuel means more power
Hope this helps
Regards
Simon

EvilBevel

Oh dear ... so it's better to have no boost at all when re-applying the throttle ?



There has been a great 'thread from hell' about all this, but I'm too tired to search for it.

To sum it up: a dump valve protects your turbo, but has negative repercussions on performance (open or recirc, doesn't matter). Before you give out these great snippets of knowledge: block your dumpvalve, drive the car, and report back what happens. You might be amazed...

motomc1

ILL TRY THAT

motomc1

ARE YOU SAYING THAT THEY RUN BETTER WITH NO DUMP VALVE .AS FAR AS PERFORMACE.AND THAT THERE ONLY THERE TO RELEVE STRESS AT THE WORST POINT.WILL CRIMP THE DUMP VALVE PIPE AND SEE WHAT HAPPENS,