single stage brake booster on our turbo leg

[flatoutfred]

Hey guys! I went to the junkyard yesterday to get a master cylinder (1 1/16 abs), while being there I also bought a single stage brake booster from impreza 93-97.

Before I swap the brake booster, I'd just like to get a little feedback from those who did that switch.

I just feel that a brake booster from a n/a is just not meant to be used in a turbo leg.


Sorry for the poor quality(cell phone)

Thanks

[Legacy777]

First, just to use the correct terminology, it's not a single "stage" booster, it is a single diaphragm booster. The one in your car currently is a tandem booster with two diaphragms connected together.

Here are some pics from the tandem booster that shows the inards

http://www.main.experiencetherave.com/s ... kebooster/
http://www.main.experiencetherave.com/s ... kebooster2


As far as the single diaphragm booster, definitely swap it in. It provides much more linear feel and brake modulation.

[Adam West]

So is this is "fix" for the different feel one gets after upgrading to larger brakes in our cars?

Really noticeable and proven by physics? Or butt-dyno approved (the soft science <grin>)?

Thanks in advance for the insight.

AW

[Legacy777]

No it's not the fix for upgrading to larger brakes. That's more a master cylinder issue.

The booster is more just a brake/pedal feel issue.

Are you asking if it's really noticable & proven? Yes it's very noticable....whether it can be proved or not by physics is a little more difficult of a question.

[flatoutfred]

Thanks Josh, I promess I'll never use the single stage booster term again. From now on, I will say: Oh, look dear, it seems like a single diaphragm booster.

I'll change the booster and mc tonight or tomorrow and I'l give you feedback.

But still, I don't get why subaru would put the tandem booster in our legacy and in the wrx if the feel is so shity.

[Legacy777]

The main reason is the amount of braking assist that can be generated with the tandem booster vs. the single diaphragm booster. Not everyone likes a firmer pedal or has the leg power to really stop the car in the event they need to jam on the brakes.

I'm sure there's other reasons too....