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Discussion Starter #22 (Edited)
They require special calipers, brake pads and they need heat to work properly otherwise they are very hard to modulate. Brembo recently came out with carbon-ceramic disc compound that should have non of these problems, but you don't want to know the price. Many high end track cars switch from factory carbon to steel disc. It just doesn't justify the costs for us mortals. :D
 

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Hello Rudi,
What about carbon discs?
We are blessed with a really light car and extremely light and cheap disc brakes (OEM are much cheaper than aftermarket and quite good).Those who want more they can easily upgrade to Rudy's options.
I would never consider carbon discs due to thir price and many porsche owners replace them with steel brakes if going to the racetrack. --> The carbon discs go back on the car when it is sold, with the brakes in perfect condition :)
 

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Discussion Starter #26
My issue with OEM discs was warping, bad de-dusting capabilities as the drilled holes always got clogged and caused weird pad wear. Rear could be lighter as well, but honestly they are decent for street use and somewhat OK for occasional track use with high end pads. For track and race focused users they are underperforming.
 

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Discussion Starter #28
Here is the list of brake setup (pads, discs and fluids) I ran so far for race/track use:

1st setup
FRONT: Stock
REAR: Stock
FLUID: Stock
DISCS: Stock 305mm/292mm
NOTE: Brake fade, heavy pad deposit, heavy disc warping, weak bite, stock brake bias. Good for a 1-2 laps.

2nd setup
FRONT: Ferodo DS2500
REAR: Ferodo DS2500
FLUID: Stock
DISCS: Stock 305mm/292mm, 2nd set
NOTE: Heavy brake fade, heavy pad deposit, heavy disc warping, weak bite, stock brake bias. Good for 2-3 laps.

3rd setup
FRONT: Ferodo UNO
REAR: Ferodo DS2500
FLUID: Stock
DISCS: Stock 305mm/292mm, 2nd set
NOTE: Medium brake fade, medium pad deposit, medium disc warping, medium bite, too much front brake bias. Good for 3-4 laps.

4th setup
FRONT: Winmax W7
REAR: Winmax W7
FLUID: Motul RBF
DISCS: Stock 305mm/292mm, 2nd set
NOTE: Medium brake fade, low pad deposit, low disc warping, high bite, stock brake bias. Good for 4-5 laps.

5th setup
FRONT: Winmax W7
REAR: Winmax W7
FLUID: Castrol SRF
DISCS: Stock 305mm/292mm, 3rd set
NOTE: Low brake fade, light pad deposit, light disc warping, high bite, stock brake bias. Good for 5-6 laps.

6th setup:

FRONT: Winmax W7
REAR: Winmax W7
FLUID: Castrol SRF
DISCS: GMS BBK kit 330mm/320mm with straight grooved discs
NOTE: No brake fade, no pad deposit, no disc warping, high bite, a bit more rear brake bias. Good for 10+ laps.

Switching from drilled to grooved discs made an enormous difference, because the stock drilled disc get the cooling holes filled with the pads dust and then the pads started to wear out in a weird pattern and then the discs get messed and start to get warped and vibrate. A bit more rearward bias helps with the trail braking too, the car doesn't push so much with the front end out on the heavy braking after the long straights. So far it feels good. We have Imola next month which is very hard on the brakes, to make the ultimate brake test.

:eek:
 

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Gales GMS
for road and some track days, is upgrade of rear only to brake kit good idea ?
with PFC grade 10 front, DS2500 rear & OE disks, there is clear too much bracking on front and ABS actions quick even with AD08R in 215.
I may also just upgrade rear pads for higher Coeff friction, to balance front ones ?
jean
 

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Discussion Starter #30
My recommendation is to always keep front and rear brake pads of the same compound or even better (higher friction coefficient) at the rear. I strongly suggest not to put better (higher friction coefficient) pads in the front as you will decrease braking perfromance due to miss-biased brake balance (too much to the front) and therefore ABS issues.

Upgrading only rear brakes with GMS BBK would provide a near perfect brake bias at about 59F / 41R vs. stock 64 F / 36R, but I wouldn't do it as the front stock rotors will sooner or later get warped and start cracking between the drilled holes and it would also look weird. On the long term, I think the only proper solution is full, front and rear BBK kit with better (higher friction coefficient) at the rear, to achieve somewhere about 61 F / 39 R brake balance.

Next level would be to swap the stock calipers with better performance calipers front and rear to get the rear end properly biased, working and to expand the selection of the rear brake pads, but we will look into this later as we are quite happy with the brake setup we have so far and it is also not gonna be a cheap fix as well.
 

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gales, OK thanks
i'll try first other pads rear, suggestion as dis not fond any pfc, but not Noisy ones
after rear kit GMS only, price ?
after also front kit
 

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Will the caliper be at the exact same position? I’m going for these wheels, and as you can see, there is absolutely no more clearance:
102731
 

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Since the caliper is going to be a bit further from the center - it should improve the clearance.
In the inward/outward plane i guess that caliper doesn't move,
but let Rudi confirm.
 

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Discussion Starter #37
Will the caliper be at the exact same position? I’m going for these wheels, and as you can see, there is absolutely no more clearance:
View attachment 102731
Now that is tighter than a teenie. ?

Exactly. The calipers will stay at the same ET but will move further away from the center providing more clearance.
 

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That is a little close for comfort.


Sent from my iPhone using Tapatalk
It’s actually enough, this picture is from a car modified for racing(still road legal), running 215/265 semi slics. Do not know lateral acceleration (G force) though. But no issues.
 
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