981 GT4 vs 991 GT3 Rotor Compatibility

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05-29-2021, 05:53 PM

carbondan

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981 GT4 vs 991 GT3 Rotor Compatibility

I'm planning on purchasing a set of Girodisc rotors to install on my 991.2 GT3 w/ OEM PCCBs.
I found a set of Girodisc rotors off a 981 GT3 w/ OEM PCCB.

I am curious if they will fit on my 991? I plan to ask Girodisc directly, but they might not be back in the office til Tuesday.
Just curious if anyone has done this before and has first-hand experience.
The 991 GT3 part number is A1-154
The 981 GT4 part number is A1-156

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05-31-2021, 04:20 PM

GrantG

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I think the center aluminum rotor bells may be of different design between GT4 and GT3.

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06-01-2021, 12:54 PM

Tom@TPC Racing

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The 5 holes on the hat are different size. CL drive pin require bigger hole than 5-lug.

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