MBC or bleed valve

[Nutternick]

I'm too impatient to wait for a MBC from eBay so was going to buy bleed valve today and was wondering if anybody uses one and what the difference was between the two?

[T5frankie]

It's called a "bleed valve" because it bleeds off some if the boost pressure so the ECU is fooled into thinking the turbo is running at lower psi than it actually is.
withaa ball-spring valve that you can adjust to stay closed until a set pressure. Say you want 15psi then the valve wont open tll that pressure is reached

[claymore]

Yep, I've always used a bleed valve to control my boost.

[stribo]

I have a bleed valve on the C70, fitted between the turbo, and TCV, and it seems to work well. It's adjusted to give 1 bar of boost, which it does without any spikes. My only concern is as it's fooling the ECU into thinking it's running less boost than it actually is, it may under fuel, but this hasn't shown up on the rolling roads I've been to. It's only fitted as a temporary measure until I get the car remapped, but for the price, it works well. As to how it compares to a MBC, I've not had one fitted, so couldn't say.

[Nutternick]

So is it best to use the bleed valve in place of the TCV completely or leave the TCV in place and use the bleed valve on the turbo side or the actuator side?

[T5frankie]

i'd wait for a ball and spring mbc mate

[stribo]

Use the bleed valve between the turbo and TCV, not between the TCV and actuator.

[Brett855tdi]

Am i being daft here... but arnt they both the same thing?

[stribo]

Am i being daft here... but arnt they both the same thing?
No mate, a bleed valve does what it says and bleeds boost off to stop the actuator opening as early as it normally would, an MBC stays shut until a preset pressure is reached, then opens to allow pressure to the actuator.

[Nutternick]

http://youtu.be/fYP4WtFTkF0

little video of it running