Superformance Cross Drill or slotted

[justbetter]

OK Lads, need some help with knowing if :

1. Can you cross drill the Superformance discs ? ( will it create fatigue spots )

2. Is Cross Drilling better than just slotting if the above is OK.

3. Should you do both ?

I have a Mk 111 Superformance.

Regards Garrett

[Aussie Mike]

Superformance Cross Dressing? I new you enjoyed "Drag" racing but this is going a bit far.

[justbetter]

GET TO WORK YOU BUGGER...


P.S Thanks for the ride this morning.

Me

[xlr8or]

Don't do it. It's to crucial to balance and strength. If you want slotted and/or drilled just buy them that way.

Just my $.02

[Aussie Mike]

Originally posted by xlr8or


Don't do it. It's to crucial to balance and strength. If you want slotted and/or drilled just buy them that way.

Just my $.02

If done accurately in the proper fixture ballance won't be affected.

Strength shouldn't be a problem either. The only problem with drilled discs I've heard of is the holes leading to cracks forming.
The reports of cracking I believe are only under extreme conditions i.e. V8 Supercar racing etc. I think it has something to do with the varying temperatures across the disc with more air/surface area around the holes meaning that section of the disk runs slightly cooler. The purpose of the holes isn't cooling but allowing the hot gasses greated by the pad rubbing against the disc to escape without pushing the pad away from the disc.

Porsche have been fitting their cars with drilled Brembo rotors for years. For a road car that gets occasional 5 lap sprint duty at the race track would this be enough abuse to cause cracking?

Drilling the discs is easy enough to do but time consuming Slotting them is relatively quick. I often wonder if brake manufactures are recomending slotting because it's less labour intesive for a CNC machine and they can churn them out quicker and cheaper?

Here's one of the disc off my car getting the drilling and slotting treatment. It's probably a bit much but I was looking for things to do while waiting for my kit to turn up.

[justbetter]

Thats not your work shop mike

I've never seen it look that clean, wheres the shavings, 16 spare wheels, 4 1/2 restored motorbikes, cobra nuts and bolts, loose scattered drill bits, loose gun powder, off cuts of billet material, daughters go cart ( nearly going ), air hoses, flood light leads, and cat on the rug in the corner....



Really mike if you gunna back you stories up with photos make the photos real and stop using the loungroom for a background

Me again

[Aussie Mike]

It's a trick I learned a while back. Just clean up the area behind what your's taking a picture of. Eventually if I take enough pictures of my various projects around the shed the whole place will get cleaned up.

Haven't you heard "A clean shed is the sign of a sick mind" That's my excuse and I'm sticking to it.

Cheers

[Mike Hausner]

STAINLESS STEEL BRAKES,here in New York, USA, does not recomend cross drilling rotors (they say cracks can develop) they recomend slotting.
Just my...er their .02.

[rdorman]

If you want to do either, slot them. Fewer question with similar results. No need to get fancy either. Two .030 x .060 (wide) slots parrallel to each other covering the pad surface but NOT coming in comtact with the ID or hub will work just fine.
Rick