Drilled rotors?

[DANNY8]

The other day I was in Repco lookin at there front rotors. I loved the look of the DBA Golds, mainly coz they're gold, and coz they're slotted and drilled. I can get them new for $88 each (retail for $166 each, so I'm savin a fair bit). But my mate that works there said one of his mates came in the day b4 (and he's a mechanic) and was also lookin at them, but ended up getting the next one down, which was just the slotted ones, he rekons any drilled rotors aren't allowed at race tracks coz they can split, and when ya car goes through scrutineering, if they see u have drilled rotors u won't pass.

Anyone know if this is true?

I've already put a set of DBA Golds on layby. I rekon they look great, and I'm under the impression that the rotors would of gone through lots of testing b4 hand, so I'm guessing they can't be all that bad.

Anyone have any good or bad experiences with drilled rotors? Just for the record, I'm also gettin new wheel bearings and Bendix pads , just need my new springs and I can put the front suspension 2gether.

[Doctor Sodways]

The problem with cross drilled rotors on road cars is that the holes get filled with brake dust, and when this dust gets hot, which it does, it heats up quicker than the disk itself and they do indeed begin to crack around the holes. Only small cracks, but each and every hole will have a crack, ill find a photo i have somewhere, an audi with cross drilled rotors after a day at the ring, every hole has a crack around it. Most people who put better rotors on road cars will use slotted only for this reason, yes the cross drilled look tougher, but they serve no real purpose on the street.

So, if i was you, i would be getting the same as the mechanic, cancel the cross drilled, and get slotted, you wont be dissapointed by the slotted on their own anyway


Edit: found those photos for ya

[LowVp]

cross drilling is all wank factor and yeah serves no real purpose

this is my front right

[shaggerz]

cross drilling is all wank factor and yeah serves no real purpose

this is my front right

far from "wank factor"... they do serve a purpose but as has been said, on road cars its not the ideal way to go about it. Slotted will give you the same reduction in the "gas cushion" effect without resulting in buildup of brake dust cracking the rotors.

[immortality]

definitly go the slotted rotors way. they work good and no hassles with the cracking etc

[DANNY8]

Thx heaps guys! You've twisted my arm :P I'll go in today and let them know to switch the rotors. Cheers.

[AirStrike]

The way I always see it, HSV along with plenty of other big name companies (Porsche, Ferrari, etc) use drilled rotors.........

[shaggerz]

they do indeed but I would be willing to bet there is also something special about their pads and calipers. Adding drilled rotors to a car that was designed with solid is probably going to be the cause of the problem hehe.

[AirStrike]

they do indeed but I would be willing to bet there is also something special about their pads and calipers. Adding drilled rotors to a car that was designed with solid is probably going to be the cause of the problem hehe.

I agree 100% and have seen the rotors crack first hand with my mates car. Just pointing out they arn't as bad as everyone seems to think.

[gslrallysport]

The way I always see it, HSV along with plenty of other big name companies (Porsche, Ferrari, etc) use drilled rotors.........

Porsche also use ceramic rotors... and they've had plenty of problems with them!!!

Yes, cross drilled rotors are a wank factor, and the only time I'd reccomend them for anyone is for a vehicle that does alot of beach driving.

The best of both worlds is RDA's dimpled rotors... look as good as drilled, are still gold anodised, but don't crack.

[Bravotwozero]

Porsche also use ceramic rotors... and they've had plenty of problems with them!!!

Yes, cross drilled rotors are a wank factor, and the only time I'd reccomend them for anyone is for a vehicle that does alot of beach driving.

The best of both worlds is RDA's dimpled rotors... look as good as drilled, are still gold anodised, but don't crack.

WTF has beach driving got to do with cross drilled rotors!?

And they most certainly aren't wank factor. The only problem is too many people expect them to last as long as standard solid rotors. You want high performance? You will have to pay the price!

Why are people hung up about looks? I cannot believe a person would upgrade their brakes purely to look cool!

What a stupid post!

[DANNY8]

Mate I'm putting all new suspension and brakes in the car I'm building up so why would I want stock gear? I can get slotted disks for the exact same price as the slotted and drilled disks ($88 each), and as I liked the look of the gold on the slotted and drilled that's wat I decided to get. Altho now that I've seen evidence of cracking I don't want them. I don't want to have to replace the disks every year or however long it takes them to crack, so that's why I'm now gonna change them over.

Thx everyone else for their help and opinions.

[immortality]

what do the V8 supercars run???? they would be about the most abused brakes in OZ

[jNINE]

The V8's run Alcon disks & calipers.

I've got DBA slotted and painted them gold (easy job) and they have gone for about 4 years (100,000 km's) without machining.

If I was to go bigger I would change to the SV5000/saloon car setup from PBR.

[304cci]

all good, but how are you getting them for $88?

[DANNY8]

My brother works at Repco and that's the staff price

Also, I've decided to just stick with the DBA golds....I was gonna get them changed over but if they f**k up I guess they'd be covered by a warranty.

[VT-565]

Cross drilled rotors dont crack due to build of brake dust in the holes.
The cause of the cracking is heat transfer in the different thicknesses of metal on the disc. The metal around the holes will cool and contract much quicker than the rest of the disc, hence the stress cracking around the holes.
For a street car, slotted rotors are more than enough. If it isnt, look at the rest of your system first.

[veclubby]

My brother works at Repco and that's the staff price

geez wat sort of discount does he get? i only get 25% at supercheap...lol

[knowledge_is_power]

Your DBA Gold Cross drilled and slotted rotors will crack as did mine and they aren't covered by warranty. They have a little clause that says they aren't covered if the rotors are exposed to conditions beyond what they are designed for. You'll also find that the gold rotors have a warning stating not for racing in their marketing material, but the slotted silver rotors don't. At the end of the day its your choice. You'll only have to replace them when it happens.

Jezz

[DANNY8]

geez wat sort of discount does he get? i only get 25% at supercheap...lol

Haha yeah sometimes the discount is pretty good. It varies a lot. My clutch was on the shelf for about $330, but I got it for about $150, so that was pretty killer. But when we looked up oils it was a different story. The cheap stuff we only seemed to get 1 or 2 dollars off, and normally the good stuff is the same, but the last time we got oil it was cheaper buying a good brand 5L bottle then the cheap 4L bottle.

Your DBA Gold Cross drilled and slotted rotors will crack as did mine and they aren't covered by warranty. They have a little clause that says they aren't covered if the rotors are exposed to conditions beyond what they are designed for. You'll also find that the gold rotors have a warning stating not for racing in their marketing material, but the slotted silver rotors don't. At the end of the day its your choice. You'll only have to replace them when it happens.

Jezz

Well like u said, if they crack I'll only have to replace them, and atleast then next time I can go for the slotted ones. It's all trial and error.

[pillowdribbler]

I have been told that the DBA Golds even being drilled have a stronger make up and tend not to crack or buckle as quick as the standard metal brake rotors.

[Tree cutter]

I had the old DBA Gold rotors on my calais and they were noisy as. I think the newer ones are a bit different. Mine only had four slots and could be fitted on either side. I replaced them with slotted only which are a bit quieter but dont stop me as quick at high speeds. My old drilled and slotted rotors did have fine cracks in them and one warped but i did give them a hard time.

[Surfwagon]

Literature for standard DBA golds say they are only for street use and not for track use, you need the 4000 or 5000 series for racing.
http://www.dba.com.au/

[sam5l]

yeh they dod dimpled rotors now they dont crack have the same effect and look simliar so id go dimpled and slotted

[crew chief]

The op asked this question in 2007 i'd say he's sorted it by now