[Otto]

i was not certain that i would be back to hpde this season, but it seems now that i will...

i have bailed on zone 2 at vir, mostly because i don't feel ready, and i know the car is not

one thing about my 2012 987.2 cayman s last year that concerned me was braking

seldom did my brakes hold up for an hpde, usually, in the last sesson or two for an event, they were scary

it got to the point where i was flushing and bleeding, it seemed, all the time

what to do?

i would like to move to a gt3 master and cup booster (low) - for more feel and control, and braided brake lines - for more consistancy

i have seen this combo on many track caymans

i don't really want to go big brakes with hat and floating ring rotors... do i need too?

i like low cost sebro slotted steel rotors and pagid black pads for now

i want to keep with 18 inch wheels, and from what i can tell, 6 piston calipers and big rotors force you into 19 - 20 inch wheels, and then tire selection goes the shit (i prefer nt01 or r888 at this time, but would love to try r7's)

i just feel a little lost right now as to what to do before the season starts

otto

[Dandelion]

Hi Otto - you're fast enough that you're reaching the limits of the stock brake system. Unfortunately, that means you need to upgrade the rotors and possibly calipers (depending on which upgrade path you choose).

The GT3 master cylinder and booster will help with feel, but it won't help the basic problem that the heat generated during a session can't be stored or dissipated fast enough.

ed

[TomChan]

Originally Posted by Varejao17

Hi Otto - you're fast enough that you're reaching the limits of the stock brake system. Unfortunately, that means you need to upgrade the rotors and possibly calipers (depending on which upgrade path you choose).

The GT3 master cylinder and booster will help with feel, but it won't help the basic problem that the heat generated during a session can't be stored or dissipated fast enough.

ed

Agreed.

[Otto]

stoptech ?

brembo ?

wilwood ?

[Dandelion]

GT4.

[TomChan]

Originally Posted by OttoBurgess

seldom did my brakes hold up for an hpde, usually, in the last sesson or two for an event, they were scary

First thing, any time a car feels scary the driver should exit from hot track. Not worth the risk for HPDE, in my opinion.

Originally Posted by OttoBurgess

it got to the point where i was flushing and bleeding, it seemed, all the time

Are you using top tier brake fluid? (i.e., SRF or PFC).

Originally Posted by OttoBurgess

i would like to move to a gt3 master and cup booster (low) - for more feel and control, and braided brake lines - for more consistancy

MC and booster isn't going to help prevent heat saturation/over heating from pure braking. Might help in an indirect way, I'll get to that.

Changing MC to one that has different diameter piston(the GT3 MC does) changes displacement of fluid volume per stroke which also changes the pressure ratio between applied pressure at the brake pedal to the pressure at the brake caliper pistons respective to piston bore size(if anything, applying more pressure may make over heating worst) and number of pistons. Usually GT3 MC is used for GT3 6-piston caliper conversion which the displacement of the extra pistons is better matched to the fluid volume per stroke of the GT3 MC.

Changing booster changes the level of power assist. The GT3 booster has less power assist than Cayman which means the driver can modulate braking force better to threshold braking to prevent ABS and PSM engagement. This is where it might help indirectly- with less power assist, there's more feel, and more modulation, which when the increased modulation range is used properly a driver can prevent ABS and PSM engagement to reduce heat in the brake system. ABS and PSM engagement causes temperature spikes in the system.

Replacing aging brake hoses is a good practice. On this car I don't know if braided hose are better than the stock hoses. The factory race cars such as GT3 Cup and GT3R uses the exact same part number hoses as any stock 987/997/996/986. Some braided hoses actually have one size smaller flow diameter(there's playing with pressure ratio again in the system) making the pedal feel firmer because you'd be pushing the same volume fluid through a smaller hole. I guess the maker do this to fulfill the advertise claim of firmer pedal. One some other model cars where the stock hoses aren't so good then braided hoses can make a big overall improvement.

Originally Posted by OttoBurgess

i don't really want to go big brakes with hat and floating ring rotors... do i need too?

At some point(relative to the driving pace + vehicle weight + available tire grip) it becomes necessary to have bigger brake system.

Originally Posted by OttoBurgess

i want to keep with 18 inch wheels, and from what i can tell, 6 piston calipers and big rotors force you into 19 - 20 inch wheels

Absolutely NOT TRUE.

Originally Posted by OttoBurgess

wheels, and then tire selection goes the shit (i prefer nt01 or r888 at this time, but would love to try r7's

All three tire you mentioned come in 19" sizes. R7 would make the problem worst by increasing grip threshold which puts more load on the brake system.

The issue might not be from braking itself. It might be from subtle PSM engagement during trail braking or corner exit throttle.

Also the suspension may be too soft for the pace causing over weight distribution to tires then ABS and PSM does their thing causing brake temperature spikes.

Bottom line, the stock brakes on a stock car at stock weight can only perform so well. Once a certain track driving pace is achieved, a driver have the following choice:
1) Don't try to improve pace, even brake 5 feet sooner and less hard. The brake system will hold up longer at slightly slower pace.
2) Invest in elaborate brake cooling system. But without increase metal mass of the rotors and its internal venting still need to bleed after every or every session.
3) Bigger rotors and space out the calipers. Or Bigger rotors and bigger calipers.
4) If its determined that brake issue is PSM-caused, install a PSM kill switch at your own risk(not recommended but some drivers do it). Usually this done after the suspension is fully sorted.

Just my opinions...I could be wrong about everything.

[Chopper Dropper]

Learn to brake better, not harder, often braking less a bit earlier can allow you to get more settled at turn in and on the gas earlier to exit faster and hopefully lower lap times.
Good choice to skip the earlier DEs, overdoing at this stage can set you back a whole lot.
Dirk

[TomChan]

Originally Posted by OttoBurgess

stoptech ?

brembo ?

wilwood ?

All of the above are excellent sources.

Also consider Essex/AP Radi-CAL kit or OEM GT3 or OEM Turbo.
Any caliper that has bigger or more piston will require bigger piston MC/booster. Also, the really badass brake systems are meant for stiffer suspension to prevent "stoppies".

On the lower budget end, Girodisk makes 340/325mm rotor kits with spacers to space out the stock calipers. They work okay for the price range.

[Vicegrip]

Originally Posted by OttoBurgess

stoptech ?

brembo ?

wilwood ?

Air. More of it. Increase as needed. Many methods to do this and some even work.

[Vicegrip]

Originally Posted by Chopper Dropper

Learn to brake better, not harder, often braking less a bit earlier can allow you to get more settled at turn in and on the gas earlier to exit faster and hopefully lower lap times.
Good choice to skip the earlier DEs, overdoing at this stage can set you back a whole lot.
Dirk

Good advice but don't feather and drag into a corner. Brake firmly and hard when needed. Same amount of energy removed in a short clean cycle is better than a long soak.