Does anyone have or know where to get a drawing or a diagram of a cross drill pattern for brake discs. I have just recieved my upgrade kit from prodrive this morning and I want to get the discs drilled. We have an inhouse machine shop where I work and they said that if I got a drawing they would do it on the CNC mill. Is this a good idea or not ? Comments please

Kev

Definatly not.
You will weaken the discs considerably.
Nuff said not going to get technical.
J.

OK, fair enough, I won't do it.

Thanks

Kev

Kevin

I have EBC disks & they are "spotted" rather than drilled.
Makes sense I guess as they act like drilled disks (when pad is on disk during braking) but retain the strength of non drilled disks because they are not drilled all the way through.

Ro.

Hmmm, that's an intesting idea. Any one else got any comments on this.

Kev

Don't drilled/grooved/spotted discs need to undergo some kind of heat treatment to strengthen them after they've been machined?

Another reason not to:

Discs are balanced in production after the cross drilling / spotting / grooving process.

To quote directly from the "Brembo Brake Disc Manual":

"In spite of casting and machining quality, slight imbalance it terms of weigh distribution may persist. This is why ventilated discs automatically and systematically balanced by removing stock. This is performed by milling...... The milling machine eliminates material around the outside of the disc, and passes continually until the disc is perfectly balanced."

Altering the balance of the discs by making your own holes / spots will cause vibration, unless you have the means to re-balance the discs afterwards.

Basically it's very inadvisable...


Rich :)

Thanks Rich, that's another good reason not to do it.

All seems like too much hard work.

Thread dead

Kev :-)

All the drilling thing does is weaken the disc and slightly improve heat dissipation, not enough to justify doing it in my eyes. :D Grooves rough up the pads and help braking slightly, but again weaken if the disc is not heat treated and proven through NDT (non destructive testing) personally, i think prodrive should know what they are doing and modifying any of their parts would be silly (and void any warranties)... dont do it :d

duh i have come too late, thread dead, like the man sed.. (hey that rhymes, i might be a poet, and not know it :D nuff sed here ....

All the drilling does in reality is produce sharp edges for stress cracks to appear ( you cannot chamfer the inside edge of the hole ). Dont do it if disc longivety is of any interest. Porsche however actually cast their disc with the holes in them, not drilled!! ( not sure about all models though, but turbo's yep )

OK guys, thanks for all your input. Much appreciated and stopped me making a BIG mistake

Kev :-)