diesel dump valves

[damo525]

hi i,ve just bought a 2002 525 turbo diesel bmw,now i,ve been told of a mate of mine to buy a dump valve for it,now i,m 35 and its a business edition model so i told him i,m not 18 anymore and i dont want my car sounding like i,ve tried to make it "boyracerish"with the noise!he then said they sound different to the normal petrol ones and its not for them kind of purposes its so it preserves my turbo from premature wear and tear,after he finished it sounded like a really good idea to put one on,and pretty stupid not to!now has anybody else done this or no if its possible or if it,s just not worth doing!thanks

[Greeney2k1]

Tbh I've never seen any performance gain or any "prolonged turbo lifetime" in my opinion they slowly damage your turbo.....when they open they release all the pressure from the housing having your turbo spool up all over again. Sudden changes in pressure / temp will surely damage it over time?

Secondly when you have one your forced to drive like a d*ck to make the pssst noise...eventually damaging your car. I say forced I mean pushed through childish need lol

Diesel ones do sound different but they will be louder because of the turbo spinning at higher pressures than petrol ones.

If you don't lioe the noise don't get one. You can spend upto £200 making the car go psst when you change gear......or get a re-map for £300 that boosts the turbo up and you will hear it much better there! Lop

[andy-mcq]

i believe that diesal dump valves are alot more expensive and if you dump all the boost your car will end up lagging so much itl be like not having a turbo! you dont ever see many people with them on diesals due to the fact there crap.

get a iphone and download the dump valve app, itl have you laughing for a full 2 mins to realise you look like a !Removed! and youl never use it again B)

[BIGjones]

You dont need one mate as BMW have installed a recirculating one as standard. All petrol and diesel cars from the factory have one but instead of the boyracer pssst the air released goes back into the inlet tract. The info above on how they work is very innaccurate. A dumpvalve or recirc valve actually does prolong turbocharger life. When you accelerate the turbo spools up forcing air up the inlet pipework, when you back off or change gear the turbo is still spinning so forcing this air up but its meeting a dead wall at the throttle butterfly. This air then 'backs up' effectivly trying to go backwards through the turbo known as compressor surge. This air tries to spin the compressor the wrong direction whilst the turbine side of the turbo is still trying to turn it the correct way. This over time wears the bearings and can cause the turbine shaft to snap. the dumpvalve or recirc allows the boost pressure to be released when you back off, this allows the turbo to spin freely with the boost pressure simply leaving the valve and causing no damage. The turbo itself isnt being slowed by the air trying to escape as this has been removed so actually spools up much more quicly reducing lag. The turbo can basically keep spinning and producing boost pressure whilst you change gear or back off without the air trying to slow it down and damage it.

Boyracers fit loud ones but these are simply valves that vent to atmosphere rather than the recirculating units that we will all have in our turbocharged cars :-)

[G4VHD]

You dont need one mate as BMW have installed a recirculating one as standard. All petrol and diesel cars from the factory have one but instead of the boyracer pssst the air released goes back into the inlet tract. The info above on how they work is very innaccurate. A dumpvalve or recirc valve actually does prolong turbocharger life. When you accelerate the turbo spools up forcing air up the inlet pipework, when you back off or change gear the turbo is still spinning so forcing this air up but its meeting a dead wall at the throttle butterfly. This air then 'backs up' effectivly trying to go backwards through the turbo known as compressor surge. This air tries to spin the compressor the wrong direction whilst the turbine side of the turbo is still trying to turn it the correct way. This over time wears the bearings and can cause the turbine shaft to snap. the dumpvalve or recirc allows the boost pressure to be released when you back off, this allows the turbo to spin freely with the boost pressure simply leaving the valve and causing no damage. The turbo itself isnt being slowed by the air trying to escape as this has been removed so actually spools up much more quicly reducing lag. The turbo can basically keep spinning and producing boost pressure whilst you change gear or back off without the air trying to slow it down and damage it.

Boyracers fit loud ones but these are simply valves that vent to atmosphere rather than the recirculating units that we will all have in our turbocharged cars :-)

I was going to say exactly the same thing..... ;)