Drilling rotors
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,108
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
I done did it years ago when I was making a BBK for an '87 MC.
You have to lay out the pattern and be mindful of the fins. I used a 3/16 drill bit and then spot faced them with a 5/16 bit. I didn't do any fancy pattern, just pretty much copied what was out there for other cars.
While I didn't have any adverse problems with them, I didn't see any gain either.
You have to lay out the pattern and be mindful of the fins. I used a 3/16 drill bit and then spot faced them with a 5/16 bit. I didn't do any fancy pattern, just pretty much copied what was out there for other cars.
While I didn't have any adverse problems with them, I didn't see any gain either.
So....I guess you're building another show car and want the bling that drilled rotors will add to it. In that case, go for it. It won't be so important if you drill through vanes and other important internal structural components of the rotor if you're just driving it to shows.
Make sure you countersink or chamfer tbe holes like you see in the pictures below. You can see the holes are stress risers where cracks will develop and propagate, but again, if you aren't tracking the car but the holes are only for cosmetic purposes, it doesn't much matter.
Make sure you countersink or chamfer tbe holes like you see in the pictures below. You can see the holes are stress risers where cracks will develop and propagate, but again, if you aren't tracking the car but the holes are only for cosmetic purposes, it doesn't much matter.
While a full radius is better than chamfering the holes, the internal holes don't get chamfered, so neither is a great benefit for street use other than making the holes appear larger.
I hope he just used the wrong terminology to describe his process.
Safety Car
Joined: Jan 2004
Posts: 4,974
Likes: 14
From: Pinellas Park Fl
St. Jude Donor '08-'09 & '12, '14
Just for reference, the holes in C6 rotors are 5/32" (4mm) and not spotfaced. The pattern/location in base rotors is far more important than Z51/F55 or GS/Z06 rotors, as they are bi-rotational. i.e. vaneless
Actually, regardless of the fact there are no vanes on base rotors, it's very important where the holes are located, even for a trailered show car. Making that kind of statement without intimate knowledge of the components can be dangerous and costly to the uninformed.
While a full radius is better than chamfering the holes, the internal holes don't get chamfered, so neither is a great benefit for street use other than making the holes appear larger.
I hope he just used the wrong terminology to describe his process.
Actually, regardless of the fact there are no vanes on base rotors, it's very important where the holes are located, even for a trailered show car. Making that kind of statement without intimate knowledge of the components can be dangerous and costly to the uninformed.
While a full radius is better than chamfering the holes, the internal holes don't get chamfered, so neither is a great benefit for street use other than making the holes appear larger.
I hope he just used the wrong terminology to describe his process.I'm not an engineer, so I used the wrong word, sue me, you understood what I was saying.
I forgot I was in a room full of Sheldons who never make a mistake and have all the answers.
I bow to your expertise
