This came up in conversation today. Do you actually need a DV? because some time attack cars run without them and turbos didn't originally have them.

From what I have read recently mate.....You don't, but it puts huge pressure on the Turbo.

If you run with out a dv you will put huge pressure in the system and without that pressure off boost escaping, the turbo will not last.

Sent from my Samsung S3

 

not a good idea to run without dv.

Sent from my Samsung S3

Im sure car manfacturers spent alot of money working this one out, i will go with what they say

Sent from my iPhone 4s

My mates sierra cosworth 4x4 which has a hybrid T3 (330 bhp) doesn't run a dump valve and hasn't for years still on the same turbo. Common mod on the cosworths so I've been told.

My mates sierra cosworth 4x4 which has a hybrid T3 (330 bhp) doesn't run a dump valve and hasn't for years still on the same turbo. Common mod on the cosworths so I've been told.

 

More common on cosworths because they have t34 type turbos which has stronger shafts than the VAG group cars.

 

The VAG group weaker shaft will suffer from the pressure build up caused from the closed throttle , and  with the rush of air hitting the turbine shaft and being chopped up by the compressor wheel causing the turbo to stall momentarily dropping the shaft from extremely high rpm to  zero and back up again consistently,

This will also cause extra lag between gear  changes due to having to spin the turbo back up to speed when back on the throttle

 

so to me not a good idea to run without a DV on these cars