986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - X-drilled & Slotted Rotors CAN be cut!

Lil bastard · 02-20-2008, 04:21 PM

Well, there's no way to tell if you did not measure the lateral runout or put a micrometer on the disc before you started.

The thickness of an OEM Boxster S disc is:

front / rear
28 mm / 24mm

The minimum allowable thickness of an OEM Boxster S disc is:

front / rear
26.0 mm / 22.0 mm

But, the OEM discs, while sometimes supplied by Zimmerman to Porsche for the 'S' model, are not the same discs that Zimmerman offers the public as aftermarket discs, so the allowances listed above may not be the same. But, the Zimmerman aftermarket x-drilled & slotted rotors have been reported to crack more readily by several owners who have installed them.

I'd measure your discs now w/ a micrometer and if inside the minimum allowance for the OEM disc, keep an eye on them for cracking, such as when you wash the wheels etc. Replace as soon as you see any cracks between holes forming. If outside the minimum allowance, I'd think about replacing them for safety's sake.

02-20-2008, 04:21 PM	#4
Lil bastard Registered User Join Date: Feb 2008 Location: Du Monde Posts: 2,199	Well, there's no way to tell if you did not measure the lateral runout or put a micrometer on the disc before you started. The thickness of an OEM Boxster S disc is: front / rear 28 mm / 24mm The minimum allowable thickness of an OEM Boxster S disc is: front / rear 26.0 mm / 22.0 mm But, the OEM discs, while sometimes supplied by Zimmerman to Porsche for the 'S' model, are not the same discs that Zimmerman offers the public as aftermarket discs, so the allowances listed above may not be the same. But, the Zimmerman aftermarket x-drilled & slotted rotors have been reported to crack more readily by several owners who have installed them. I'd measure your discs now w/ a micrometer and if inside the minimum allowance for the OEM disc, keep an eye on them for cracking, such as when you wash the wheels etc. Replace as soon as you see any cracks between holes forming. If outside the minimum allowance, I'd think about replacing them for safety's sake. __________________ 1990 Porsche 964 Carrera 4 Cabriolet 1976 BMW 2002 1990 BMW 325is 1999 Porsche Boxster (gone, but not forgotten) http://i933.photobucket.com/albums/a...smiley-003.gif Never drive faster than your Guardian Angel can fly!