Upgrading V8 master cylinder and brake booster
Discussion
Does anyone know if the master cylinder and brake booster of pre 2012.25 Vantage models can be updated with the newer ones used in the Vantage V8S? Surprisingly AM has reduced the overall piston area of the 6-pot caliper by almost 16% compared to the earlier used 4-pot calipers. Here are the figures
- 4-pot calipers (40 and 44mm) = 5,554 mm² piston area
- 6-pot calipers (28, 30 and 36mm) = 4,680 mm² piston area
If piston area becomes smaller it needs more pressure to achieve the same or even a better clamping force. Ergo, V8S models must have a bigger master cylinder and/or otherwise a new brake booster, pedal ratio still 1:4 as far as I know. Doesn't make sense just to install bigger rotors/pads and reducing clamping force at the same time.
I am thinking about to upgrade the brake system of my pre 2012.25MY Vantage. Would be great to exchange some thoughts and experiences.
- 4-pot calipers (40 and 44mm) = 5,554 mm² piston area
- 6-pot calipers (28, 30 and 36mm) = 4,680 mm² piston area
If piston area becomes smaller it needs more pressure to achieve the same or even a better clamping force. Ergo, V8S models must have a bigger master cylinder and/or otherwise a new brake booster, pedal ratio still 1:4 as far as I know. Doesn't make sense just to install bigger rotors/pads and reducing clamping force at the same time.
I am thinking about to upgrade the brake system of my pre 2012.25MY Vantage. Would be great to exchange some thoughts and experiences.
It's not possible to update a pre 212.25 with a V8S unit as the earlier Booster is an active type and has additional electrical connectors on the booster can for the internal electronics, the master cylinder also has the pressure sensor fitted on the older type.
The V8S system is classed as a passive Booster and has the "active" electronic components, and the pressure sensor, in the ABS module, you'd get lots of faults and likely no functioning DSC.
FYI, the master cylinders are the same size between the two, but are a completely new casting on the newer units.
The V8S system is classed as a passive Booster and has the "active" electronic components, and the pressure sensor, in the ABS module, you'd get lots of faults and likely no functioning DSC.
FYI, the master cylinders are the same size between the two, but are a completely new casting on the newer units.
KnowsAnAston said:
It's not possible to update a pre 212.25 with a V8S unit as the earlier Booster is an active type and has additional electrical connectors on the booster can for the internal electronics, the master cylinder also has the pressure sensor fitted on the older type.
The V8S system is classed as a passive Booster and has the "active" electronic components, and the pressure sensor, in the ABS module, you'd get lots of faults and likely no functioning DSC.
FYI, the master cylinders are the same size between the two, but are a completely new casting on the newer units.
Many thanks, this is a very useful information. Do you know where the differences are and how they change the behavior of the brake and/or ABS system? Does it have an influence regarding reliability?The V8S system is classed as a passive Booster and has the "active" electronic components, and the pressure sensor, in the ABS module, you'd get lots of faults and likely no functioning DSC.
FYI, the master cylinders are the same size between the two, but are a completely new casting on the newer units.
Btw, do you eventually know the piston diameter of the brake master cylinder and the force of the brake booster of pre 2012.25MY models? Thx.
Impasse said:
Would you be able to describe the faults with your current set up?
The current system does not have any faults. It's just the braking response when hot that shall be improved. I tried different brake pads, i.e. Brembo (HP1000 / HP2000), PFC, Pagid and found a good compromise between street and race track using Pagid RSL pads. The standard brake pad does no really work well, it's more or less crap. However, improving the overall performance will require a combination of bigger calipers, pads and disc rotors.I have some experiences in upgrading brake systems (I live close to the Nurburgring) but the AM V8 brake system is a new subject. As far as I know all pre 2012.25MY V8 models have Brembo OEM 4-pot monobloc calipers with 40/44mm piston at the front and 34/36mm at the rear. Dimensions are almost identical with Brembo's Gran Tourismo P-type brake caliper, i.e. bolting space, offset, etc.
I recently got my hands on a 6-pot caliper and was surprised that piston area has been reduced compared to the 4-pot calipers. My first assumption was, AM has chosen a different brake booster with higher force or have changed master cylinder and pedal ratio. Meanwhile I found out it doesn't.
However, there is most probably a good solution using Brembo equipment to leave piston areas unaltered but having a 6-pot caliper using a bigger brake pad and rotor. This would be a different solution than AM has chosen. But it will follow a general rule that says, increase piston area first, than pad area and finally rotor diameter. Unfortunately there is no Brembo caliper with bigger pistons instead of pure racing calipers. But those ones are in absence of dust seals not suitable for road use.
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