what disks r beta? x-drilled or slotted?

In theory, x drilled rotors (as they are usually slotted and cross drilled)provide better cooling, more abrasion on the pad and more venting for associated gasses...

In practice? Doubt you could tell the difference on a standard brake setup.

I prefer slotted. I've heard about and seen to many cracked crossdrilled discs.

I'm running DBA slotted discs now.

exactly what i've heard too eh - i've got DBA slotteds, and very happy with them

I had DBA cross drilled/slotted rotors on my last car,an XH ute, and they were excellent, you could give them a real hard time and they still worked well. Never had problems with cracking. I can't compare them with slotted only rotors in my experience though, as I've never given slotted brakes a hard time.

If your not racing, or giving it a extra hard time, slotteds are fine, they get rid of the gas build up, and cool better, cross drilled cool even better, but only if you race everywhere, tromping the brakes all the time.

When I changed my rotors recently I was talked out of Cross-Drilled, ended up with Slotted. They said they can often crack and it's excessive for what I needed them for - just normal driving.

You've got to weigh up the pros and cons. Both cross-drilled and slotted have positives and negatives.

Crossdrilled:

Benefits:

1. It reduces weight. Less unsprung weight, better handling (in theory at least). Less mass to cool down when you get the discs glowing red.
2. Better cooling through more ventilation
3. Vastly increased fade resistance due to gasses being able to get out from between the disc and pad

Negative:

Cross drilling reduces the surface area of the disc, so you need more pad pressure to get the same braking at before.

Slotted:

Benefits:

1. Reduces weight
2. Better cooling (although not as much as cross-drilling)
3. Vastly reduces brake fade
4. Keeps the pad deglazed

Negative:

Again, reduces surface area.


It is VITAL if you run a slotted disc that you run a GOOD pad. The slots actually have a sharpish edge which takes a teeny-weeny slice off the pad every time it passes the pad's surface. If you use a cheap, soft compound pad, you cut the pad away and get a significantly reduced pad life.

As for cross-drilled discs cracking... well, any disc will crack if you subject it to severe thermal shock. If you nail the brakes from 150km all the time with stone cold brakes, you will crack your discs no matter how fancy or rudimentary they are. Probably the reason why people crack cross-drilled discs is because of the reduces surface area.... you need more pad pressure which generates more heat, more quickly and this can increase the thermal shock on the disc. Also, you can't just drill holes anywhere. It has to be done right, however, any Joe Bloggs can take his discs off, put them in a bench drill and turn them into cross-drilled discs and stuff them up 100km later

I don't see anythign wrong with cross-drilled. Porsche use them and their drivers don't have any problems. I don't see many Porsche drivers schreeching to a top at every set of lights either. If what you guys are saying about cross-drilled is right (being overdone) then Porsche drivers would have HEAPS of trouble being relatively light cars with massive brakes, compared to a Falcon which is a relatively heavy car with relatively small brakes!

EDIT: Also, if you go with DBA, get their Kangaroo Paw discs. I've read wonderful things about it.... greater cooling, more even cooling, much stronger that standard vented discs and lighter.

my theory, f**k off dba crossdrilleds as they will crack if your a heavy braker and tend to use it for a bit of fun on the streets

i learnt ive got rda slotteds and as ive been told by several people including a dba reseller not to go go crossdrilled slotted as they 'always' crack.

ill post up pix soon if anyones interested lol

ive heard all those stories too.. too many times!
ive got dba slotted rotors with brembo pads on my elxr.. works awesome!

my mate went on a tour through dba the other day and they told him crossed drilled are crap and dont bother.

before anyone starts flaming my a***, thats from dba and not me!

I hear lots of 2nd hand stories about DBA X-Drilled cracking. I've given mine a HELL of a time (front and rear x-drilled/slotted) and theyre just simply awesome. I use them with the Bendix Ultimates. Ive been bad and never had my discs machined.. theyve done about 20-30k of hard work, with about 4 sets of front pads. Massive lips, gouges from metal on metal. *shrug* theyre tops.

From people who've owned them, they only praise them

For those who dont own them, they seem to have lots of bad stories. Go do the math.

DBA dont recommend their 'DBA Sport' rotors for track use. thats written everywhere.

I have to agree with Waggin. My PERSONAL experience with DBA cross drilled has been nothing but positive. I could get the front brakes smoking and still rely on them to stop the car. No cracks, no warps. I was running Ultimates as Waggin is. Another positive is they shed water extremely well too when you're driving in the rain and hit the brakes. No feeling of 's**t, wet discs!'
I think a lot of the warping/cracking issues people have with rotors is from not cooling them down properly. Parking your car with stinking hot rotors has to do harm to them when you consider one part of the rotor is stuck under a hot caliper and stays hotter than the rest of the rotor which is cooling down in the atmosphere.
I'll always drive a couple of slow sedate kilometers after thrashing the brakes to cool them down.

I work for Repco in NZ and one of the brands we sell, are your aussy made DBA product. I have been to a couple of training sessions with their sales and marketing guy Steve, and he advised that the Gold or X drilled are more of a marketing thing as people demand the agressive look of a X drilled rotor, particullary with bigger wheels where you can see the rotor. (they do look cool) - However, he also informs that their is no preformance advantage between slotted only and x drilled rotors. This is from the manufacturer. As mentioned earlier their biggest advance is the kangeroo paw design, which cools more effeciently and is stronger.

I put the slotted option on my EL V8 and once bedded in - it stops noticably better than standard. I have fitted Lucas pads - don't know if they are sold in Aus - and it stops well even with my boat in tow!