Danno

I think you may have mis-read the Tom's site:

"The piston sizes used in the big red or GTS 4-piston Brembo calipers are the same size as those used in the M030 option S4 calipers, namely 36 and 44 mm. The brake pad width is also the same 132 mm."

This just says that the BigReds/Blacks have the same pistons inside the calipers as the 928-S4 calipers.... however...

"However, the brake pad depth is increased substantially to match the larger rotor diameter."

This second part clearly says that they use different pads and different rotors. It's like this statement:

"The door-handles on the '86 Toyota Supra are the same as those used in the '86 Lotus Elan, namely a flush aerodynamic handle. The color is also the same natural plastic black finish. However, the doors are significantly lighter to match the higher-performing car."

Here's what they look like next to each other:


And the specifications:

928-S4 / 951 TurboS / 993 C2,C4
Brake pistons: 44/36mm
Rotor diameter: 304x32mm
Pad size: 132x48mm (12mm thick)
Pad surface-area: 112.5 cm2

BigRed / 928-GTS BigBlack / 964 Turbo 3.6 / 993 TT,RS,C4S
Brake pistons: 44/36mm
Rotor diameter: 322x32mm
Pad size: 132x58mm (12mm thick)
Pad surface-area: 151 cm2

Another picture:

djazzy99

ohhh, i see. so the pads and rotors that are used in those calipaers are the difference. thanks danno for pointing that out. does anybody know how well these two brake systems perform compared to each other? ie- are they relatively close in braking distance etc?

facboy

i'm no expert, but i think braking distance would be pretty similar initially. the 928 S4s would probably fade earlier though if u were really pushing it - but i've heard people say that they've never seen the s4s fade on the track.

lots of people have experience with this though - has anybody upgraded from s4s to big reds? any major difference?