Drilling wont help a lot to that fading consern. Use the same calibers and install better brake pads read street brake pads. They wont fade so easily and have better grip.
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I have drilled the discs from one of my previous cars. They will start to crack from hole to hole. Specially when you have run them hot in a track and then you drive into water pool etc. First they get twisted and after that they start to crack... So dont drill.
Your mountain driving is propably not nothing compared to racing what they can take also few laps with stock brakes. CRX is so light that it should not have any problems on normal roads of any kind. People race those cars with stock discs and race pads in 24 hour races in Finland
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