"Servo Assisted" brakes and forced induction motor

[stormseeker 0]

Driving in to work tonight, a thought struck me - (as I was just daydreaming about supercharging my VR ;-) )

 

I always thought that servo assistance on brakes worked on the inlet manifold vacuum - but on a forced induction engine, don't you have positive (i.e. greater than atmospheric) pressure in the manifold?

 

Does the servo work the same? Or is it just wired differently?

[Joe M 0]

Have wondered this as well, the answer I got basically stated that fi cars arent always under boost, when off the accelerator there is a vacuum which builds up for the brakes and there is a valve of some sort to stop the vacuum being lost when under boost.

[Fat Tony 0]

Good call Joe I couldnt figure that out especially when boosting so I though you really shouldnt be breaking and producing boost at the same time and didnt want to test my weak theory out :lol:

[Kevin Bacon 5]

The direction of inlet charge flow will always 'pull' air out of the servo (creating a vacuum) regardless of induction method :lol:

 

Slapping a turbo on my 16V made absolutely no difference to the way the standard braking setup behaved.

 

K

[G60JAY 0]

In line with the brake servo is a one way valve which allows air to only flow one way. NA cars have a vacuum in the inlet manifold, except at wot.Most forced induction cars work the same.

Jason