Ap brakes not spongy on standard mc

Porsche brakes spongy on standard mc

You gotta make sure you have a good vacuum also !!

just depends on piston size, the ap setup is a decent setup unlike a retro fit 'any old porsche caliper setup', the desired piston size can be calculated with a mathematical equation...don't ask me for it cos i don't know

Yeah it's easy 1+1 = 4

;-)

how is it you know that, but don't know about lube to stop bum rash?

Lmfao

hehehe

Ap brakes not spongy on standard mc

Porsche brakes spongy on standard mc

You gotta make sure you have a good vacuum also !!

Please what do you mean by vacuum???

Vaccuum lines feeding the servo (vacuum booster)

These dry and crack, meaning you loose full assistance of the servo, leading to a 'spongey' brake pedal

The effect of this will be amplified if you then increase the piston surface area you're trying to power.

Here's a listing for the full R8 GT 6pot front, 4pot rear ceramic kit, which includes a new brake booster

Here's a listing for the full R8 GT 6pot front, 4pot rear ceramic kit, which includes a new brake booster

Chrrrrrrrrist!

Compare that booster to the pony little thing fitted to mk.4 based cars

Golf/Octy

R8 GT

ps

That booster might be compatible with the 23mm MC ...

The bigger servo is just to compensate for the larger amount of force needed to push the larger master cylinder piston. It doesn't get around the MC to caliper piston ratio it just means that the pedal feels the same under your foot when a bigger MC is fitted.

Having a leaking vac line to the servo would actually make a spongey pedal feel better rather than worse as you would have to push the pedal harder for the same braking force

Having a leaking vac line to the servo would actually make a spongey pedal feel better rather than worse as you would have to push the pedal harder for the same braking force

Think you're misunderstanding

Without working servo, brakes will not generate full 'bite' without pushing hard - which some 'experts' describe as 'spongey' - which the 'experts' assume is due to oversized pistons

With servo working, no spongyness, sharp braking

The larger the piston area you're trying to run, clearly, the greater the noticable effect will be

This I have directly experienced

The bigger servo is just to compensate for the larger amount of force needed to push the larger master cylinder piston. It doesn't get around the MC to caliper piston ratio it just means that the pedal feels the same under your foot when a bigger MC is fitted.

That kit used the same MC as the basic R8 v8 TTBOMK

Without the servo it would feel like you are trying to push a brick through the floor with much reduced pedal travel for the same leg effort.

Oversize caliper pistons without changing the MC will give a soft pedal with much more pedal travel for the same leg effort. Feeling like you are pushing a sponge with your foot.

They give the opposite effects. I can't see how they are confused

When the servo completely fails yes, brakes suddenly go very hard, feeling bit like an airlock

However, uptill full failure some folks have assume their inability to push the brake pedal hard enough as 'spongey'

A true 'spongey' pedal can (normally) be pushed to the floor/stop

Basically a case of mis-diagnosis

ps

I've had leaky old vac lines replaced, which gave me full bite out of my 6pots

I've then had these new lines melt through on me on a spirited drive, which resulted in rock hard pedal, where the actually brake pedal flexed before being able to generate any brake force - which was fun